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Sample records for very-late activation antigen

  1. Differential role for very late antigen-5 in mobilization and homing of hematopoietic stem cells

    NARCIS (Netherlands)

    Wierenga, P. K.; Weersing, E.; Dontje, B.; de Haan, G.; van Os, R.

    2006-01-01

    The role of very late antigen-5 (VLA-5) in homing and mobilization of hematopoietic stem cells from normal bone marrow (NBM) and bone marrow (MBM) and peripheral blood (MPB) from mobilized mice was investigated. We found a decreased number of VLA-5-expressing cells in the lineage-negative fraction

  2. 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...... significant differences between the two strains. Expression of VLA-1 was also found to be redundant regarding the ability of effector T cells to eliminate virus from internal organs of i.v. infected mice. Using delayed-type hypersensitivity (DTH) assays to evaluate subdermal CD8(+) T......, the current findings indicate that the expression of VLA-1 is not pivotal for T-cell-mediated antiviral immunity to a systemic infection....

  3. Targeted blockade in lethal West Nile virus encephalitis indicates a crucial role for very late antigen (VLA-4-dependent recruitment of nitric oxide-producing macrophages

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    Getts Daniel R

    2012-10-01

    Full Text Available Abstract Infiltration of Ly6Chi monocytes from the blood is a hallmark of viral encephalitis. In mice with lethal encephalitis caused by West Nile virus (WNV, an emerging neurotropic flavivirus, inhibition of Ly6Chi monocyte trafficking into the brain by anti-very late antigen (VLA-4 integrin antibody blockade at the time of first weight loss and leukocyte influx resulted in long-term survival of up to 60% of infected mice, with subsequent sterilizing immunity. This treatment had no effect on viral titers but appeared to be due to inhibition of Ly6Chi macrophage immigration. Although macrophages isolated from the infected brain induced WNV-specific CD4+ T-cell proliferation, T cells did not directly contribute to pathology, but are likely to be important in viral control, as antibody-mediated T-cell depletion could not reproduce the therapeutic benefit of anti-VLA-4. Instead, 70% of infiltrating inflammatory monocyte-derived macrophages were found to be making nitric oxide (NO. Furthermore, aminoguanidine-mediated inhibition of induced NO synthase activity in infiltrating macrophages significantly prolonged survival, indicating involvement of NO in the immunopathology. These data show for the first time the therapeutic effects of temporally targeting pathogenic NO-producing macrophages during neurotropic viral encephalitis.

  4. A third-phase cutaneous (very late phase response after elicitation with dinitrofluorobenzene in passively or actively sensitized mice

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    Eiichi Tahara

    1999-01-01

    Full Text Available Previous studies have reported that the mice passively sensitized with anti-dinitrophenol (DNP IgE antibody exhibited IgE-mediated cutaneous reaction with an immediate phase response (IPR at 1 h and a late phase response (LPR at 24 h after the challenge of dinitrofluorobenzene (DNFB. We found that the third-phase inflammatory reaction with intense and persisting infiltration of eosinophils, named ‘very late phase reaction (vLPR’, was induced following IPR and LPR in response to DNFB in actively and passively sensitized mice, and that the peak response of vLPR was at 8 days after the challenge. This reaction was slightly observed in non-sensitized mice. Since the accumulation of eosinophils in vLPR was markedly observed when compared with that of LPR at 24 h, the vLPR may be an important reaction in allergic diseases. The development of vLPR was partly decreased in mast cell-deficient WBB6F1-W/Wv mice and was absent in T cell-deficient BALB/c-nu/nu mice in passive sensitization. These results indicate that the vLPR in the triphasic cutaneous reaction may be mainly mediated by T cells and partially by mast cells and/or IgE antibody, and consequently lead to an intense ear swelling accompanying massive infiltration of eosinophils.

  5. The interaction affinity between vascular cell adhesion molecule-1 (VCAM-1 and very late antigen-4 (VLA-4 analyzed by quantitative FRET.

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    Sandeep Chakraborty

    Full Text Available Very late antigen-4 (VLA-4, a member of integrin superfamily, interacts with its major counter ligand vascular cell adhesion molecule-1 (VCAM-1 and plays an important role in leukocyte adhesion to vascular endothelium and immunological synapse formation. However, irregular expressions of these proteins may also lead to several autoimmune diseases and metastasis cancer. Thus, quantifying the interaction affinity of the VCAM-1/VLA-4 interaction is of fundamental importance in further understanding the nature of this interaction and drug discovery. In this study, we report an 'in solution' steady state organic fluorophore based quantitative fluorescence resonance energy transfer (FRET assay to quantify this interaction in terms of the dissociation constant (Kd. We have used, in our FRET assay, the Alexa Fluor 488-VLA-4 conjugate as the donor, and Alexa Fluor 546-VCAM-1 as the acceptor. From the FRET signal analysis, Kd of this interaction was determined to be 41.82 ± 2.36 nM. To further confirm our estimation, we have employed surface plasmon resonance (SPR technique to obtain Kd = 39.60 ± 1.78 nM, which is in good agreement with the result obtained by FRET. This is the first reported work which applies organic fluorophore based 'in solution' simple quantitative FRET assay to obtain the dissociation constant of the VCAM-1/VLA-4 interaction, and is also the first quantification of this interaction. Moreover, the value of Kd can serve as an indicator of abnormal protein-protein interactions; hence, this assay can potentially be further developed into a drug screening platform of VLA-4/VCAM-1 as well as other protein-ligand interactions.

  6. E-selectin and very late activation antigen-4 mediate adhesion of hematopoietic progenitor cells to bone marrow endothelium

    NARCIS (Netherlands)

    Rood, P. M.; Dercksen, M. W.; Cazemier, H.; Kerst, J. M.; von dem Borne, A. E.; Gerritsen, W. R.; van der Schoot, C. E.

    2000-01-01

    Adhesion of CD34+ hematopoietic progenitor cells (HPCs) to sinusoidal endothelium probably plays a key role in homing of transplanted CD34+ HPCs to the bone marrow (BM). We have investigated the role of various adhesion molecules in the interaction of purified CD34+ HPCs derived from BM or

  7. VERY LATE PHOTOMETRY OF SN 2011fe

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    Kerzendorf, W. E. [Department of Astronomy and Astrophysics, University of Toronto, 50 Saint George Street, Toronto, ON M5S 3H4 (Canada); Taubenberger, S.; Seitenzahl, I. R.; Ruiter, A. J., E-mail: wkerzendorf@gmail.com [Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Straße 1, D-85748 Garching (Germany)

    2014-12-01

    The Type Ia supernova SN 2011fe is one of the closest supernovae of the past decades. Due to its proximity and low dust extinction, this object provides a very rare opportunity to study the extremely late time evolution (>900 days) of thermonuclear supernovae. In this Letter, we present our photometric data of SN 2011fe taken at an unprecedented late epoch of ≈930 days with GMOS-N mounted on the Gemini North telescope (g = 23.43 ± 0.28, r = 24.14 ± 0.14, i = 23.91 ± 0.18, and z = 23.90 ± 0.17) to study the energy production and retention in the ejecta of SN 2011fe. Together with previous measurements by other groups, our result suggests that the optical supernova light curve can still be explained by the full thermalization of the decay positrons of {sup 56}Co. This is in spite of theoretical predicted effects (e.g., infrared catastrophe, positron escape, and dust) that advocate a substantial energy redistribution and/or loss via various processes that result in a more rapid dimming at these very late epochs.

  8. Outcome of Very Late Relapse in Patients with Hodgkin's Lymphomas

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    Francesco Gaudio

    2011-01-01

    Full Text Available Recurrences of Hodgkin's Lymphoma (HL 5 years after the initial therapy are rare. The aim of this study is to report a single centre experience of the clinical characteristics, outcome, and toxicity of pts who experienced very late relapses, defined as relapses that occurred 5 or more years after the achievement of first complete remission. Of 532 consecutive pts with classical HL treated at our Institute from 1985 to 1999, 452 pts (85% achieved a complete remission. Relapse occurred in 151 pts: 135 (29.8% within 5 years and 16 over 5 years (3.5%, very late relapses. Very late relapses occurred after a median disease-free interval of 7 years (range: 5–18. Salvage treatment induced complete remission in 14 pts (87.5%. At a median of 4 years after therapy for very late relapse, 10 pts (63% are still alive and free of disease and 6 (37% died (1 from progressive HL, 1 from cardiac disease, 1 from thromboembolic disease, 1 from HCV reactivation, and 2 from bacterial infection. The probability of failure-free survival at 5 years was 75%. The majority of deaths are due to treatment-related complications. Therapy regimens for very late relapse HL are warranted to minimize complications.

  9. [Very late drug-eluting stent thrombosis by stent fracture].

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    Cheaito, R; Tritar, A; Scemama, A; Ferrag, W; Goy, P; Haziza, F; Benamer, H

    2015-12-01

    The superiority of drug-eluting stents in reducing the risk of in-stent restenosis compared to bare-metal stents is no longer challenged. Nevertheless, the drug-eluting stents may carry long-term risk of late and very late stent thrombosis. The promoting factors of this complication are usually divided into three chapters depending on the patient, the procedure and the stent. Indeed, the literature has reported several parameters related to the stent itself, such as its length, the malapposition, its diameter, but also more rarely the occurrence of stent fracture. We present the case of a patient admitted for myocardial infarction after a very late thrombosis of Cypher drug-eluting stent four years after its implantation and related to stent fracture. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  10. Capgras syndrome in a very late onset, treatment resistant schizophrenia.

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    Ain, M K Nurul; Rosdinom, R; Raynuha, M

    2015-09-01

    We report a Malay man, with underlying chronic medical illnesses, presenting with positive symptoms of schizophrenia, including Capgras syndrome (CS) at the age of 73. Physical examination and blood investigations were normal and brain CT scan showed age-related cerebral atrophy. Neuropsychological assessment showed probable right hemisphere lesions but relatively intact memory and intellectual functions. Several neuroleptics including depot injections were tried but ineffective. Positive symptoms including CS eventually improved with clozapine before his death from myocardial infarction. This case report highlights the uncommon occurrence of CS in treatment resistant schizophrenia (TRS) of very late onset and its treatment challenges.

  11. Mechanisms of Very Late Drug-Eluting Stent Thrombosis Assessed by Optical Coherence Tomography

    DEFF Research Database (Denmark)

    Taniwaki, Masanori; Radu, Maria D; Zaugg, Serge

    2016-01-01

    BACKGROUND: The pathomechanisms underlying very late stent thrombosis (VLST) after implantation of drug-eluting stents (DES) are incompletely understood. Using optical coherence tomography, we investigated potential causes of this adverse event. METHODS AND RESULTS: Between August 2010 and Decemb...

  12. Idiopathic very late-onset cerebellar ataxia: a Brazilian case series.

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    Teive, Hélio A G; Moscovich, Mariana; Moro, Adriana; Farah, Marina; Arruda, Walter O; Munhoz, Renato P

    2015-11-01

    The authors present a Brazilian case series of eight patients with idiopathic very-late onset (mean 75.5 years old) cerebellar ataxia, featuring predominantly gait ataxia, associated with cerebellar atrophy. 26 adult patients with a diagnosis of idiopathic late onset cerebellar ataxia were analyzed in a Brazilian ataxia outpatient clinic and followed regularly over 20 years. Among them, 8 elderly patients were diagnosed as probable very late onset cerebellar ataxia. These patients were evaluated with neurological, ophthalmologic and Mini-Mental Status examinations, brain MRI, and EMG. 62.5% of patients were males, mean age was 81.9 years-old, and mean age of onset was 75.5 years. Gait cerebellar ataxia was observed in all patients, as well as, cerebellar atrophy on brain MRI. Mild cognitive impairment and visual loss, due to macular degeneration, were observed in 50% of cases. Chorea was concomitantly found in 3 patients. We believe that this condition is similar the one described by Marie-Foix-Alajouanine presenting with mild dysarthria, associated with gait ataxia, and some patients had cognitive dysfunction and chorea.

  13. Very late stent thrombosis of bare-metal coronary stent nine years after primary percutaneous coronary intervention

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    Đurić Predrag

    2016-01-01

    Full Text Available Introduction. Stent thrombosis (ST in clinical practice can be classified according to time of onset as early (0–30 days after stent implantation, which is further divided into acute ( 30 days and very late (> 12 months. Myocardial reinfaction due to very late ST in a patient receiving antithrombotic therapy is very rare, and potentially fatal. The procedure alone and related mechanical factors seem to be associated with acute/subacute ST. On the other hand, in-stent neoathero-sclerosis, inflammation, premature cessation of antiplatelet therapy, as well as stent fracture, stent malapposition, un-covered stent struts may play role in late/very late ST. Some findings implicate that the etiology of very late ST of bare-metal stent (BMS is quite different from those following drug-eluting stent (DES implantation. Case report. We presented a 56-year old male with acute inferoposterior ST segment elevation myocardial infarction (STEMI related to very late stent thrombosis, 9 years after BMS implantation, despite antithrombotic therapy. Thrombus aspiration was successfully performed followed by percutaneous coronary intervention (PCI with implantation of DES into the pre-viously implanted two stents to solve the in-stent restenosis. Conclusion. Very late stent thrombosis, although fortu-nately very rare, not completely understood, might cause myocardial reinfaction, but could be successfully treated with thrombus aspiration followed by primary PCI. Very late ST in the presented patient might be connected with neointimal plaque rupture, followed by thrombotic events.

  14. IVUS Findings in Late and Very Late Stent Thrombosis. A Comparison Between Bare-metal and Drug-eluting Stents.

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    Fuentes, Lara; Gómez-Lara, Josep; Salvatella, Neus; Gonzalo, Nieves; Hernández-Hernández, Felipe; Fernández-Nofrerias, Eduard; Sánchez-Recalde, Ángel; Alfonso, Fernando; Romaguera, Rafael; Ferreiro, José Luis; Roura, Gerard; Teruel, Luis; Gracida, Montserrat; Marcano, Ana Lucrecia; Gómez-Hospital, Joan-Antoni; Cequier, Ángel

    2017-09-01

    Stent thrombosis (ST) is a life-threatening complication after stent implantation. Intravascular ultrasound is able to discern most causes of ST. The aim of this study was to compare intravascular ultrasound findings between bare-metal stents (BMS) and drug-eluting stents (DES) in patients with late (31 days to 1 year) or very late ST (> 1 year). Of 250 consecutive patients with late or very late ST in 7 Spanish institutions, 114 patients (45.5% BMS and 54.5% DES) were imaged with intravascular ultrasound. Off-line intravascular ultrasound analysis was performed to assess malapposition, underexpansion, and neoatherosclerosis. The median time from stent implantation to ST was 4.0 years with BMS and 3.4 years with DES (P = .04). Isolated malapposition was similarly observed in both groups (36.5% vs 46.8%; P = .18) but was numerically lower with BMS (26.6% vs 48.0%; P = .07) in patients with very late ST. Isolated underexpansion was similarly observed in both groups (13.5% vs 11.3%; P = .47). Isolated neoatherosclerosis occurred only in patients with very late ST and was more prevalent with BMS (22.9%) than with DES (6.0%); P = .02. At 2.9 years' follow-up, there were 0% and 6.9% cardiac deaths, respectively (P = .06) and recurrent ST occurred in 4.0% and 5.2% of patients, respectively (P = .60). Malapposition was the most common finding in patients with late and very late ST and is more prevalent with DES in very late ST. In contrast, neoatherosclerosis was exclusively observed in patients with very late ST and mainly with BMS. Copyright © 2017 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

  15. [Activities of treg cells stimulated by soluble adult worm antigen and egg antigen of Schistosoma japonicum].

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    Dong, Xiao-Xiao; Zhang, Cui; Yang, Xiao-Wei; Li, Yong; Chen, Xiao-Jun; Xue, Xue; Zhang, Wei-Wei; Xu, Zhi-Peng; Kong, Wen-Jun; Zhu, Ji-Feng; Zhou, Sha; Liu, Feng; Su, Chuan

    2013-04-01

    To observe and compare the effects of soluble adult worm antigen (SWA) and soluble egg antigen (SEA) of Schistosoma japonicum on the induction of Treg cells and the suppressive activity of Treg cells. Splenocytes were prepared from mice treated with PBS, SWA, and SEA, respectively, and then the proportions of Treg cells and the levels of IL-10 and TGF-beta in Treg cells were determined by FACS. The purified Treg cells from the mice treated as above-mentioned were detected for their immunosuppressive activities by incorporation of [3H] thymidine for the final 16 h of culture. Compared to SWA, SEA induced the higher proportion of Treg cells with a stronger suppressive activity, which produced the higher levels of IL-10 and TGF-beta (P < 0.05). SEA significantly induces Treg cells and enhances their immunosuppressive activity.

  16. Yokukansan (TJ-54) for treatment of very-late-onset schizophrenia-like psychosis: an open-label study.

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    Miyaoka, Tsuyoshi; Wake, Rei; Furuya, Motohide; Liaury, Kristian; Ieda, Masa; Kawakami, Kazunori; Tsuchie, Keiko; Fukushima, Michiyo; Ishihara, Kotomi; Araki, Tomoko; Hashioka, Sadayuki; Horiguchi, Jun

    2013-05-15

    Although schizophrenia affects all age groups, late or very-late-onset schizophrenia-like psychosis has not been well studied, and various treatment issues remain unresolved. The objective of the present study was to evaluate the efficacy and safety of yokukansan (TJ-54), Japanese herbal medicine, monotherapy in a diagnostically homogenous group of elderly patients without cognitive impairment suffering from very-late-onset schizophrenia. Forty patients of mean age 73.1±4.8 years, fulfilling both the recent consensus criteria for very late-onset schizophrenia-like psychosis and the DSM-IV-TR criteria for schizophrenia, were assessed by the brief psychiatric rating scale, the clinical global impression scale-severity, and positive and negative syndrome scale at baseline and after 4 weeks administration of TJ-54 (2.5-7.5 g/day). In addition, abnormal movements were evaluated with the Simpson-Angus scale, Barnes Akathisia scale, and abnormal involuntary movement scale. A highly significant (p54 was very well tolerated by the patients, and no clinically significant adverse effects were observed. Scores on all abnormal movement scales did not differ significantly prior to and after TJ-54 treatment. Preliminary results indicate that TJ-54 appears to be an efficacious and safe herbal medicine for treatment of very-late-onset schizophrenia-like psychosis. Copyright © 2013 Elsevier GmbH. All rights reserved.

  17. Late and very-late first-contact schizophrenia and the risk of dementia--a nationwide register based study

    DEFF Research Database (Denmark)

    Kørner, Alex; Lopez, Ana Garcia; Lauritzen, Lise

    2009-01-01

    OBJECTIVE: To examine whether late and very-late first-contact schizophrenia carry a risk for later development of dementia. METHODS: By linkage of the psychiatric and the somatic nation-wide registers of all out- and in-patients with hospital contact in Denmark, we identified all patients...... with first ever contact during the period from January 1994 to December 2001 with one of the index main diagnoses: late (age >or=40) and very-late first-contact (age >or=60) schizophrenia. First contact osteoarthritis patients as well as data on the general population were used as controls. The first...... diagnosis of dementia for each individual at discharge or at out-patient contact was established. The probability of getting a dementia diagnosis is estimated using Poisson regression models with dementia as the outcome of interest. RESULTS: Twelve thousand six hundred and sixteen and 7,712 individuals were...

  18. Unusually very late-onset new growth of intraocular retinoblastoma: A case report and review of literature

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    Yeshigeta Gelaw

    2017-04-01

    Conclusions and importance: Despite initial satisfactory treatment and complete regression of the tumor, very late-onset new growth of intraocular retinoblastoma can occur. Hence, life-long follow-up in all patients with retinoblastoma is warranted, given the risk for new tumor formation even later in life. To our knowledge, this is the first report of new growth of intraocular retinoblastoma after regression for more than a decade.

  19. Very Late Local Relapse of Ewing's Sarcoma of the Head and Neck treated with Aggressive Multimodal Therapy

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    J. Thariat

    2008-01-01

    Full Text Available Ewing's sarcoma's relapse rarely occurs more than two years after the initial diagnosis. We report the case of a 26-year-old man with a history of Ewing's sarcoma of the left maxillary sinus at the age of 10 who presented with a very late local relapse, 16 years after the first occurrence of disease. Ultimate control was achieved after multimodal therapy including surgery, high-dose chemotherapy, and radiotherapy. This report indicates that local relapses of Ewing's sarcoma can be treated with curative intent in selected cases.

  20. Structure of a ganglioside with Cad blood group antigen activity

    NARCIS (Netherlands)

    Vliegenthart, J.F.G.; Gillard, B.K.; Blanchard, D.; Bouhours, J.-F.; Cartron, J.-P.; Kuik, J.A. van; Kamerling, J.P.; Marcus, D.M.

    1988-01-01

    The Cad antigen is a rare erythrocyte blood group antigen expressed on both sialoglycoprotein and ganglioside structures. It is related both serologically and biochemically to the Sd' blood group antigen expressed on over 90% of Caucasian erythrocytes. We reported previously that Cad erythrocytes

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

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    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. Central diabetes insipidus as a very late relapse limited to the pituitary stalk in Langerhans cell histiocytosis.

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    Nakagawa, Shunsuke; Shinkoda, Yuichi; Hazeki, Daisuke; Imamura, Mari; Okamoto, Yasuhiro; Kawakami, Kiyoshi; Kawano, Yoshifumi

    2016-07-01

    Central diabetes insipidus (CDI) and relapse are frequently seen in multifocal Langerhans cell histiocytosis (LCH). We present two females with multifocal LCH who developed CDI 9 and 5 years after the initial diagnosis, respectively, as a relapse limited to the pituitary stalk. Combination chemotherapy with cytarabine reduced the mass in the pituitary stalk. Although CDI did not improve, there has been no anterior pituitary hormone deficiency (APHD), neurodegenerative disease in the central nervous system (ND-CNS) or additional relapse for 2 years after therapy. It was difficult to predict the development of CDI in these cases. CDI might develop very late in patients with multifocal LCH, and therefore strict follow-up is necessary, especially with regard to symptoms of CDI such as polydipsia and polyuria. For new-onset CDI with LCH, chemotherapy with cytarabine might be useful for preventing APHD and ND-CNS.

  3. Association of Localized Hypersensitivity and In-Stent Neoatherosclerosis with the Very Late Drug-Eluting Stent Thrombosis

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    Yamaji, Kyohei; Kubo, Shunsuke; Inoue, Katsumi; Kadota, Kazushige; Kuramitsu, Shoichi; Shirai, Shinichi; Ando, Kenji; Nobuyoshi, Masakiyo; Mitsudo, Kazuaki; Kimura, Takeshi

    2014-01-01

    Background Localized hypersensitivity reaction, delayed arterial healing, and neoatherosclerosis inside the stent have been suggested as the underlying pathologic mechanisms of very late stent thrombosis (VLST) of drug-eluting stent (DES). The present study sought to explore the prevalence of inflammatory cell infiltrates and evidence for fragments of atherosclerotic plaques in the aspirated thrombi in patients with DES VLST. Methods and Results From April 2004 to September 2012, 48 patients with stent thrombosis (ST) of DES underwent thrombus aspiration with retrieved material sufficient for the histopathologic analysis; early ST (EST, within 30 days): N = 17, late ST (LST, between 31 and 365 days): N = 7, and very late ST (VLST, >1 year): N = 24. Eosinophil fraction in the aspirated thrombi was significantly higher in patients with VLST (8.2±5.7%) as compared with those with EST (4.3±3.0%) and LST (5.5±3.8%) (P = 0.03). Eosinophil fraction in the aspirated thrombi was significantly higher in 12 VLST patients with angiographic peri-stent contrast staining (PSS) and/or incomplete stent apposition (ISA) by intravascular ultrasound than in 12 VLST patients without PSS or ISA (10.6±6.1% versus 5.8±4.1%, P = 0.03). Evidences for fragments of atherosclerotic plaques in the aspirated thrombi were observed only in 3 (13%) out of 24 patients with DES VLST. Conclusions Eosinophil fraction in the aspirated thrombi was significantly higher in patients with DES VLST as compared with those with EST and LST. Evidences for fragments of atherosclerotic plaques were relatively uncommon in patients with DES VLST. PMID:25423451

  4. Association of localized hypersensitivity and in-stent neoatherosclerosis with the very late drug-eluting stent thrombosis.

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    Kyohei Yamaji

    Full Text Available Localized hypersensitivity reaction, delayed arterial healing, and neoatherosclerosis inside the stent have been suggested as the underlying pathologic mechanisms of very late stent thrombosis (VLST of drug-eluting stent (DES. The present study sought to explore the prevalence of inflammatory cell infiltrates and evidence for fragments of atherosclerotic plaques in the aspirated thrombi in patients with DES VLST.From April 2004 to September 2012, 48 patients with stent thrombosis (ST of DES underwent thrombus aspiration with retrieved material sufficient for the histopathologic analysis; early ST (EST, within 30 days: N = 17, late ST (LST, between 31 and 365 days: N = 7, and very late ST (VLST, >1 year: N = 24. Eosinophil fraction in the aspirated thrombi was significantly higher in patients with VLST (8.2±5.7% as compared with those with EST (4.3±3.0% and LST (5.5±3.8% (P = 0.03. Eosinophil fraction in the aspirated thrombi was significantly higher in 12 VLST patients with angiographic peri-stent contrast staining (PSS and/or incomplete stent apposition (ISA by intravascular ultrasound than in 12 VLST patients without PSS or ISA (10.6±6.1% versus 5.8±4.1%, P = 0.03. Evidences for fragments of atherosclerotic plaques in the aspirated thrombi were observed only in 3 (13% out of 24 patients with DES VLST.Eosinophil fraction in the aspirated thrombi was significantly higher in patients with DES VLST as compared with those with EST and LST. Evidences for fragments of atherosclerotic plaques were relatively uncommon in patients with DES VLST.

  5. Very late complications of cervical arthroplasty: results of 2 controlled randomized prospective studies from a single investigator site.

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    Hacker, Francis M; Babcock, Rebecca M; Hacker, Robert J

    2013-12-15

    Prospective, single-site, randomized, Food and Drug Administration-approved investigational device exemption clinical trials of 2 cervical arthroplasty (CA) devices. To evaluate complications with CA occurring more than 4 years after the surgical procedure in Food and Drug Administration clinical trials of the Bryan and Prestige LP arthroplasty devices. Reports of several randomized clinical studies have shown CA to be a safe and effective alternative to anterior cervical fusion in the treatment of degenerative cervical disc disorders. A majority include follow-up intervals of 4 years or less. Between 2002 and 2006, 94 patients were enrolled in Food and Drug Administration studies of the Bryan and Prestige LP cervical disc devices. Charts, imaging studies, and hospital records were reviewed for those who underwent arthroplasty and returned more than 4 years after their surgical procedure with neck-related pain or dysfunction. Excluding adjacent segment disease that occurred with a similar rate for patients who underwent fusion and arthroplasty, 5 patients, all treated with arthroplasty, returned for evaluation of neck and arm symptoms between 48 and 72 months after surgery. Four patients had peridevice vertebral body bone loss. One patient had posterior device migration and presented with myelopathy. Three required revision surgery and 2 were observed. Four patients maintained follow-up and reported stabilization or improvement in symptoms. Despite their similarities, CA and fusion are not equivalent procedures in this study in regard to very late complications. Similar to large joint arthroplasty, delayed device-related complications may occur with CA. These complications commenced well beyond the time frame for complications associated with more traditional cervical spine procedures. Both patients and surgeons should be aware of the potential for very late device-related complications occurring with CA and the need for revision surgery. 1.

  6. Biodegradable nanoellipsoidal artificial antigen presenting cells for antigen specific T-cell activation.

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    Meyer, Randall A; Sunshine, Joel C; Perica, Karlo; Kosmides, Alyssa K; Aje, Kent; Schneck, Jonathan P; Green, Jordan J

    2015-04-01

    Non-spherical nanodimensional artificial antigen presenting cells (naAPCs) offer the potential to systemically induce an effective antigen-specific immune response. In this report it is shown biodegradable ellipsoidal naAPCs mimic the T-Cell/APC interaction better than equivalent spherical naAPCs. In addition, it is demonstrated ellipsoidal naAPCs offer reduced non-specific cellular uptake and a superior pharmacokinetic profile compared to spherical naAPCs. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Stent malapposition, as a potential mechanism of very late stent thrombosis after bare-metal stent implantation: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Higuma, Takumi, E-mail: higuma@cc.hirosaki-u.ac.jp; Abe, Naoki; Hanada, Kenji; Yokoyama, Hiroaki; Tomita, Hirofumi; Okumura, Ken

    2014-04-15

    A 90-year-old man was admitted to our hospital with acute ST-segment elevation myocardial infarction. He had a history of post-infarction angina pectoris 79 months ago and had a bare-metal stent (BMS) implanted in the proximal left anterior descending artery at our hospital. Emergent coronary angiography demonstrated thrombotic occlusion in the previously stented segment. After catheter thrombectomy, antegrade flow was restored, but 90% stenosis with haziness persisted in the proximal and distal portions of the previously stented segment. Intravascular ultrasound imaging showed interstrut cavities or stent malapposition at the proximal and distal sites of stented segment. In close proximity to the sites, residual thrombi were also observed. Optical coherence tomography (OCT) demonstrated neither lipid-laden neointimal tissue nor rupture but clearly demonstrated residual thrombus adjacent to the malapposed region in addition to the stent malapposition. PCI with balloon was successfully performed and stent apposition was confirmed by OCT. Stent malapposition is an unusual mechanism of very late stent thrombosis after BMS implantation. OCT can clearly reveal the etiology of stent thrombosis.

  8. The role of CD4 in antigen-independent activation of isolated single T lymphocytes

    DEFF Research Database (Denmark)

    Kelso, A; Owens, T

    1988-01-01

    The membrane molecule CD4 (L3T4) is thought to facilitate activation of Class II H-2-restricted T cells by binding to Ia determinants on antigen-presenting cells. Recent reports suggest that CD4 can also contribute to antigen-independent activation by anti-T cell receptor (TCR) antibodies. An ass...

  9. Increased prevalence of late stage T cell activation antigen (VLA-1) in active juvenile chronic arthritis

    DEFF Research Database (Denmark)

    Ødum, Niels; Morling, Niels; Platz, P

    1987-01-01

    in remission, and controls. The prevalence of T suppressor/inducer (CD4+,Leu8+) cells was higher in remission JCA (17%) than in active JCA (11%) and controls (10%). This increase, however, did not reach statistical significance. In conclusion, late stage but not early stage T cell activation antigens were......The presence of activated T cells as judged from the reaction with monoclonal antibodies (MoAb) against (a) a late stage T cell activation antigen (VLA-1), (b) the interleukin 2 (IL2) receptor (CD25), and (c) four different HLA class II molecules (HLA-DR, DRw52, DQ, and DP) was studied in 15...... patients with active juvenile chronic arthritis (JCA), 10 patients with JCA in remission, and 11 age matched, healthy controls. In addition, the distribution of T 'helper/inducer' (CD4+), T 'suppressor/inducer' (CD4+, Leu8+), T 'suppressor/cytotoxic' (CD8+), and 'natural killer' (NK) cells (CD16...

  10. Immune activation by casein dietary antigens in bipolar disorder

    NARCIS (Netherlands)

    Severance, E.G.; Dupont, D.; Dickerson, F.B.; Stallings, C.R.; Origoni, A.E.; Krivogorsky, B.; Yang, S.; Haasnoot, W.; Yolken, R.H.

    2010-01-01

    Objectives: Inflammation and other immune processes are increasingly linked to psychiatric diseases. Antigenic triggers specific to bipolar disorder are not yet defined. We tested whether antibodies to bovine milk caseins were associated with bipolar disorder, and whether patients recognized

  11. Phosphatase active antigens in sea urchin eggs and embryos. II. A comparison between the activities in unfertilized eggs and plutei.

    Science.gov (United States)

    Westin, M

    1975-06-01

    Phosphatase activities in sea urchin eggs and plutei were investigated by means of histochemical staining of immunoprecipitates. Two protein fractions were obtained by extraction in a hypotonic medium and by detergent treatment of the residual pellet. Three distinctly different phosphatase activities were discerned, nucleoside diphosphatase (EC 3.6.1.6.), acid phosphatase (EC 3.1.3.2.) and alkaline phosphatase (EC 3.1.3.1.). The nucleoside diphosphatase activity, which was confined to one antigen, was present in both water soluble and detergent extracts and at roughly the same concentration in eggs and plutei. By means of a monospecific antiserum the immunological identify of this antigen was established in all instances. The acid phosphatase activity, which was displayed by ten detergent extracted antigens in eggs, was only found in five detergent extracted antigens in plutei. This decrease in number of enzyme active antigens was also reflected by a general decrease in number of enzyme active antigens was also reflected by a general decrease in activity as assessed by quantitative determinations. Furthermore, by means of absorbed antisera it was established that two or three of the acid phosphatase active antigens were "egg specific". Another acid phosphatase active antigen, which was common to both developmental stages, was investigated by a monospecific antiserum. While this antigen was found in both soluble fractions, it was only enzymatically active when extracted with detergent. Alkaline phosphatase active antigens were only found in the detergent extract of plutei. However, immunoprecipitates with this activity appeared both with antiserum against unfertilized eggs and with antiserum against plutei. This suggests that the egg contained the antigens in an enzymatically inactive form.

  12. Deglycosylation influences the oxidation activity and antigenicity of myeloperoxidase.

    Science.gov (United States)

    Wang, Jia; Li, Jian-Nan; Cui, Zhao; Zhao, Ming-Hui

    2016-09-19

    Myeloperoxidase (MPO) is pathogenic in ANCA associated vasculitis. It also acts as bactericidal agent. MPO has five N-linked glycosylation sites on its heavy chains. The effect of glycosylation pattern to the functions of MPO is barely known. We used eight glycosidases to remove different glycans on MPO separately. The chlorination activity of MPO, the binding between ceruloplasmin and MPO, and the reversing effect of MPO-ANCA to this binding were measured. Three de-glycosylated MPOs were used to assay the influence of deglycosylation on microbicidal effect of MPO. Compared with intact MPO, chlorination activity of deglycosylated MPO declined, in which removing of β-galactopyranoside (0.35 ± 0.02 vs. 0.50 ± 0.04, P < 0.001) and α-linked sialic acid (0.35 ± 0.02 vs. 0.50 ± 0.04, P < 0.001) presented the most significance. Deglycosylation reduced the binding capacity between MPO and its physiological inhibitor-ceruloplasmin, with the most significance on the removal of innermost GlcNAc (0.37 ± 0.04 vs. 1.06 ± 0.11, P < 0.001). Binding between MPO and ceruloplasmin was hardly reversed by MPO-ANCA after deglycosylation, especially on the removal of α-linked sialic acid (71.2 ± 5.1% vs. 88.3 ± 1.0%, P = 0.009), chitobiose core (73.6 ± 1.9% vs. 88.3 ± 1.0%, P = 0.001) and GlcNAc (77.9 ± 1.9% vs. 88.3 ± 1.0%, P = 0.002). Removal of innermost GlcNAc, β-galactopyranoside and α-neuraminidase could weaken the bactericidal effect of MPO, especially the removal of α-neuraminidase (P < 0.001). Deglycosylation decreased oxidation activity of MPO and its binding with ceruloplasmin. Deglycosylation could also decrease the microbicidal effect of MPO, which might contribute to severer infections and inflammation. Deglycosylated MPO presented less antigenicity to MPO-ANCA, which indicated the contribution of glycans to MPO epitopes. This article is protected by copyright. All rights reserved.

  13. Activated Brain Endothelial Cells Cross-Present Malaria Antigen.

    Science.gov (United States)

    Howland, Shanshan W; Poh, Chek Meng; Rénia, Laurent

    2015-06-01

    In the murine model of cerebral malaria caused by P. berghei ANKA (PbA), parasite-specific CD8+ T cells directly induce pathology and have long been hypothesized to kill brain endothelial cells that have internalized PbA antigen. We previously reported that brain microvessel fragments from infected mice cross-present PbA epitopes, using reporter cells transduced with epitope-specific T cell receptors. Here, we confirm that endothelial cells are the population responsible for cross-presentation in vivo, not pericytes or microglia. PbA antigen cross-presentation by primary brain endothelial cells in vitro confers susceptibility to killing by CD8+ T cells from infected mice. IFNγ stimulation is required for brain endothelial cross-presentation in vivo and in vitro, which occurs by a proteasome- and TAP-dependent mechanism. Parasite strains that do not induce cerebral malaria were phagocytosed and cross-presented less efficiently than PbA in vitro. The main source of antigen appears to be free merozoites, which were avidly phagocytosed. A human brain endothelial cell line also phagocytosed P. falciparum merozoites. Besides being the first demonstration of cross-presentation by brain endothelial cells, our results suggest that interfering with merozoite phagocytosis or antigen processing may be effective strategies for cerebral malaria intervention.

  14. Activated Brain Endothelial Cells Cross-Present Malaria Antigen.

    Directory of Open Access Journals (Sweden)

    Shanshan W Howland

    2015-06-01

    Full Text Available In the murine model of cerebral malaria caused by P. berghei ANKA (PbA, parasite-specific CD8+ T cells directly induce pathology and have long been hypothesized to kill brain endothelial cells that have internalized PbA antigen. We previously reported that brain microvessel fragments from infected mice cross-present PbA epitopes, using reporter cells transduced with epitope-specific T cell receptors. Here, we confirm that endothelial cells are the population responsible for cross-presentation in vivo, not pericytes or microglia. PbA antigen cross-presentation by primary brain endothelial cells in vitro confers susceptibility to killing by CD8+ T cells from infected mice. IFNγ stimulation is required for brain endothelial cross-presentation in vivo and in vitro, which occurs by a proteasome- and TAP-dependent mechanism. Parasite strains that do not induce cerebral malaria were phagocytosed and cross-presented less efficiently than PbA in vitro. The main source of antigen appears to be free merozoites, which were avidly phagocytosed. A human brain endothelial cell line also phagocytosed P. falciparum merozoites. Besides being the first demonstration of cross-presentation by brain endothelial cells, our results suggest that interfering with merozoite phagocytosis or antigen processing may be effective strategies for cerebral malaria intervention.

  15. Activated Brain Endothelial Cells Cross-Present Malaria Antigen

    Science.gov (United States)

    Howland, Shanshan W.; Poh, Chek Meng; Rénia, Laurent

    2015-01-01

    In the murine model of cerebral malaria caused by P. berghei ANKA (PbA), parasite-specific CD8+ T cells directly induce pathology and have long been hypothesized to kill brain endothelial cells that have internalized PbA antigen. We previously reported that brain microvessel fragments from infected mice cross-present PbA epitopes, using reporter cells transduced with epitope-specific T cell receptors. Here, we confirm that endothelial cells are the population responsible for cross-presentation in vivo, not pericytes or microglia. PbA antigen cross-presentation by primary brain endothelial cells in vitro confers susceptibility to killing by CD8+ T cells from infected mice. IFNγ stimulation is required for brain endothelial cross-presentation in vivo and in vitro, which occurs by a proteasome- and TAP-dependent mechanism. Parasite strains that do not induce cerebral malaria were phagocytosed and cross-presented less efficiently than PbA in vitro. The main source of antigen appears to be free merozoites, which were avidly phagocytosed. A human brain endothelial cell line also phagocytosed P. falciparum merozoites. Besides being the first demonstration of cross-presentation by brain endothelial cells, our results suggest that interfering with merozoite phagocytosis or antigen processing may be effective strategies for cerebral malaria intervention. PMID:26046849

  16. 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.

  17. Bioactive polysaccharide-based pH-sensitive polymers for cytoplasmic delivery of antigen and activation of antigen-specific immunity.

    Science.gov (United States)

    Yuba, Eiji; Yamaguchi, Ayaka; Yoshizaki, Yuta; Harada, Atsushi; Kono, Kenji

    2017-03-01

    For establishment of cancer immunotherapy, antigen carriers are needed which have functions not only to deliver antigen into cytosol of dendritic cells (DCs), which induces antigen-specific cellular immune responses, but also to activate DCs. We previously reported cytoplasmic delivery of antigen using liposomes modified with pH-sensitive polymers such as carboxylated poly(glycidol)s or dextran. Modification using these polymers provides stable liposomes with pH-sensitive fusogenic/membrane-disruptive ability. For this study, bioactive polysaccharide-based pH-sensitive polymers were constructed to achieve not only cytoplasmic delivery of antigen but also activation of DCs. Curdlan and mannan were used as bioactive polysaccharides because they are known to activate DCs via their respective interactions with Dectin-1 and Dectin-2. Carboxylated curdlan and mannan promoted Th1 cytokine production from DCs, indicating the activation of DCs by these polysaccharide derivatives. These polymer-modified liposomes released their contents at weakly acidic pH and delivered model antigenic proteins into cytosol of DCs. Subcutaneous administration of curdlan derivative-modified or mannan derivative-modified liposomes induced strong antigen-specific immune responses and stronger antitumor effects than those of liposomes modified with dextran derivative. Therefore, bioactive polysaccharide-modified liposomes that achieve both cytoplasmic delivery of antigen and activation of DCs are promising for cancer immunotherapy. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Relation between laboratory test results and histological hepatitis activity in individuals positive for hepatitis B surface antigen and antibodies to hepatitis B e antigen

    NARCIS (Netherlands)

    ter Borg, F.; ten Kate, F. J.; Cuypers, H. T.; Leentvaar-Kuijpers, A.; Oosting, J.; Wertheim-van Dillen, P. M.; Honkoop, P.; Rasch, M. C.; de Man, R. A.; van Hattum, J.; Chamuleau, R. A.; Reesink, H. W.; Jones, E. A.

    1998-01-01

    BACKGROUND: Hepatitis B surface antigen (HBsAg) and antibodies to hepatitis B e antigen (anti-HBe) commonly coexist, and laboratory tests are often requested to assess histological hepatitis activity. An optimum panel of tests has not been found and the usefulness of hepatitis B virus (HBV) DNA

  19. Selective Activation of Antigen-Experienced T Cells by Anti-CD3 Constrained on Nanoparticles

    Science.gov (United States)

    Lo, Ying-Chun; Edidin, Michael A.; Powell, Jonathan D.

    2013-01-01

    Activation of T cells through the T cell receptor (TCR) is mediated by the TCR-CD3 signaling complex. Cross linking of this complex with antibodies directed against CD3 leads to potent activation of T cells. However, such activation is not antigen-specific. We exploited the observation that the TCR-CD3 complex is clustered on T cells that have been activated by antigen by using anti-CD3 nanoparticles to selectively activate antigen-experienced mouse T cells. We find that constraining anti-CD3 on the surface of a nanoparticle markedly and selectively enhances proliferation and cytokine production of antigen-experienced T cells but does not activate naïve T cells. This effect was recapitulated in heterogeneous cultures containing mixtures of antigen-specific CD4+ or CD8+ T cells and bystander T cells. Furthermore, in vivo anti-CD3 coated nanoparticles increased the expansion of antigen-specific T cells following vaccination. Overall, these findings indicate that anti-CD3 coated nanoparticles could be use to enhance the efficacy of vaccines and immunotherapy. The results also suggest constraining a ligand on the surface of a nanoparticle might as general strategy for selectively targeting clustered receptors. PMID:24098054

  20. Circulating fibroblast activation protein activity and antigen levels correlate strongly when measured in liver disease and coronary heart disease.

    Directory of Open Access Journals (Sweden)

    Shirley Uitte de Willige

    Full Text Available Circulating fibroblast activation protein (cFAP is a constitutively active enzyme expressed by activated fibroblasts that has both dipeptidyl peptidase and endopeptidase activities. We aimed to assess the correlation between cFAP activity and antigen levels and to compare variations in levels.In plasma of 465 control individuals, 368 patients with coronary heart disease (CHD and 102 hepatitis C virus (HCV infected patients with severe liver disease before and after liver transplant, cFAP activity levels were measured with a newly developed cFAP activity assay. In the same samples, cFAP antigen levels were measured using a commercially available cFAP ELISA. Correlation analyses between activity and antigen levels were performed by calculating Pearson's correlation coefficient (ρ. Additionally, normal ranges, determinants and differences between cohorts and between anticoagulants were investigated.cFAP activity and antigen levels significantly correlated in controls (ρ: 0.660, p<0.001 and in CHD patients (ρ: 0.709, p<0.001. cFAP activity and antigen levels in the HCV cohort were significantly lower in the samples taken after liver transplantation (p<0.001 and normalized toward levels of healthy individuals. Furthermore, cFAP activity and antigen levels were higher in men and significantly associated with body mass index. Also, cFAP activity and antigen levels were higher in EDTA plasma as compared to the levels in citrated plasma from the same healthy individuals.For analyzing cFAP levels, either activity levels or antigen levels can be measured to investigate differences between individuals. However, it is of importance that blood samples are collected in the same anticoagulant.

  1. Antigen display, T-cell activation, and immune evasion during acute and chronic ehrlichiosis.

    Science.gov (United States)

    Nandi, Bisweswar; Chatterjee, Madhumouli; Hogle, Kathryn; McLaughlin, Maura; MacNamara, Katherine; Racine, Rachael; Winslow, Gary M

    2009-10-01

    How spatial and temporal changes in major histocompatibility complex/peptide antigen presentation to CD4 T cells regulate CD4 T-cell responses during intracellular bacterial infections is relatively unexplored. We have shown that immunization with an ehrlichial outer membrane protein, OMP-19, protects mice against fatal ehrlichial challenge infection, and we identified a CD4 T-cell epitope (IA(b)/OMP-19(107-122)) that elicited CD4 T cells following either immunization or infection. Here, we have used an IA(b)/OMP-19(107-122)-specific T-cell line to monitor antigen display ex vivo during acute and chronic infection with Ehrlichia muris, a bacterium that establishes persistent infection in C57BL/6 mice. The display of IA(b)/OMP-19(107-122) by host antigen-presenting cells was detected by measuring intracellular gamma interferon (IFN-gamma) production by the T-cell line. After intravenous infection, antigen presentation was detected in the spleen, peritoneal exudate cells, and lymph nodes, although the kinetics of antigen display differed among the tissues. Antigen presentation and bacterial colonization were closely linked in each anatomical location, and there was a direct relationship between antigen display and CD4 T-cell effector function. Spleen and lymph node dendritic cells (DCs) were efficient presenters of IA(b)/OMP-19(107-122), demonstrating that DCs play an important role in ehrlichial infection and immunity. Chronic infection and antigen presentation occurred within the peritoneal cavity, even in the presence of highly activated CD4 T cells. These data indicated that the ehrlichiae maintain chronic infection not by inhibiting antigen presentation or T-cell activation but, in part, by avoiding signals mediated by activated T cells.

  2. Enhancement of human natural cytotoxicity by Plasmodium falciparum antigen activated lymphocytes

    DEFF Research Database (Denmark)

    Theander, T G; Pedersen, B K; Bygbjerg, I C

    1987-01-01

    stimulation enhanced the cytotoxic activity and induced strong proliferative responses in all MNC preparations. The role of NK cells in the protection against malaria is unknown, but they play a role in the protection against virus infection and in the immune surveillance against cancer. Our findings indicate...... cell (NK cell) sensitive cell line, K562, were measured. It was found that SPag stimulation enhanced cytotoxic activity of MNC from donors whose lymphocytes exhibited a strong proliferative response to the antigen. MNC with low proliferative responsiveness showed increased cytotoxic activity if the MNC...... that malaria antigens either directly or through the activation of immunoregulatory cells enhance the NK cell activity....

  3. Aptamers for CD Antigens: From Cell Profiling to Activity Modulation

    Directory of Open Access Journals (Sweden)

    Amin Nozari

    2017-03-01

    Full Text Available Nucleic acid-based aptamers are considered to be a promising alternative to antibodies because of their strong and specific binding to diverse targets, fast and inexpensive chemical synthesis, and easy labeling with a fluorescent dye or therapeutic agent. Cluster of differentiation (CD proteins are among the most popular antigens for aptamers on the cell surface. These anti-CD aptamers could be used in cell biology and biomedicine, from simple cell phenotyping by flow cytometry or fluorescent microscopy to diagnosis and treatment of HIV/AIDS to cancer and immune therapies. The unique feature of aptamers is that they can act simultaneously as an agonist and antagonist of CD receptors depending on a degree of aptamer oligomerization. Aptamers can also deliver small interfering RNA to silence vital genes in CD-positive cells. In this review, we summarize nucleic acid sequences of anti-CD aptamers and their use, which have been validated in multiple studies.

  4. Mathematical models of e-antigen mediated immune tolerance and activation following prenatal HBV infection.

    Directory of Open Access Journals (Sweden)

    Stanca M Ciupe

    Full Text Available We develop mathematical models for the role of hepatitis B e-antigen in creating immunological tolerance during hepatitis B virus infection and propose mechanisms for hepatitis B e-antigen clearance, subsequent emergence of a potent cellular immune response, and the effect of these on liver damage. We investigate the dynamics of virus-immune cells interactions, and derive parameter regimes that allow for viral persistence. We modify the model to account for mechanisms responsible for hepatitis B e-antigen loss, such as seroconversion and virus mutations that lead to emergence of cellular immune response to the mutant virus. Our models demonstrate that either seroconversion or mutations can induce immune activation and that instantaneous loss of e-antigen by either mechanism is associated with least liver damage and is therefore more beneficial for disease outcomes.

  5. Enhancement of human natural cytotoxicity by Plasmodium falciparum antigen activated lymphocytes.

    Science.gov (United States)

    Theander, T G; Pedersen, B K; Bygbjerg, I C; Jepsen, S; Larsen, P B; Kharazmi, A

    1987-12-01

    Mononuclear cells (MNC) isolated from malaria immune donors and from donors never exposed to malaria were stimulated in vitro with soluble purified Plasmodium falciparum antigens (SPag) or PPD. After 7 days of culture the proliferative response and the cytotoxic activity against the natural killer cell (NK cell) sensitive cell line, K562, were measured. It was found that SPag stimulation enhanced cytotoxic activity of MNC from donors whose lymphocytes exhibited a strong proliferative response to the antigen. MNC with low proliferative responsiveness showed increased cytotoxic activity if the MNC were preincubated with interleukin 2 (IL-2) for one hour before the start of the cytotoxic assay. SPag activation did not enhance the cytotoxic activity of MNC which did not respond to the antigen in the proliferation assay, and preincubation of these cells with IL-2 did not increase the activity. PPD stimulation enhanced the cytotoxic activity and induced strong proliferative responses in all MNC preparations. The role of NK cells in the protection against malaria is unknown, but they play a role in the protection against virus infection and in the immune surveillance against cancer. Our findings indicate that malaria antigens either directly or through the activation of immunoregulatory cells enhance the NK cell activity.

  6. Inhibiting DNA methylation activates cancer testis antigens and expression of the antigen processing and presentation machinery in colon and ovarian cancer cells.

    Science.gov (United States)

    Siebenkäs, Cornelia; Chiappinelli, Katherine B; Guzzetta, Angela A; Sharma, Anup; Jeschke, Jana; Vatapalli, Rajita; Baylin, Stephen B; Ahuja, Nita

    2017-01-01

    Innovative therapies for solid tumors are urgently needed. Recently, therapies that harness the host immune system to fight cancer cells have successfully treated a subset of patients with solid tumors. These responses have been strong and durable but observed in subsets of patients. Work from our group and others has shown that epigenetic therapy, specifically inhibiting the silencing DNA methylation mark, activates immune signaling in tumor cells and can sensitize to immune therapy in murine models. Here we show that colon and ovarian cancer cell lines exhibit lower expression of transcripts involved in antigen processing and presentation to immune cells compared to normal tissues. In addition, treatment with clinically relevant low doses of DNMT inhibitors (that remove DNA methylation) increases expression of both antigen processing and presentation and Cancer Testis Antigens in these cell lines. We confirm that treatment with DNMT inhibitors upregulates expression of the antigen processing and presentation molecules B2M, CALR, CD58, PSMB8, PSMB9 at the RNA and protein level in a wider range of colon and ovarian cancer cell lines and treatment time points than had been described previously. In addition, we show that DNMTi treatment upregulates many Cancer Testis Antigens common to both colon and ovarian cancer. This increase of both antigens and antigen presentation by epigenetic therapy may be one mechanism to sensitize patients to immune therapies.

  7. EVALUATION OF HUMAN LEUKOCYTE ANTIGEN CLASS I AND II ANTIGENS IN HELICOBACTER PYLORI-POSITIVE PEDIATRIC PATIENTS WITH ACTIVE GASTRITIS AND DUODENAL ULCER

    Directory of Open Access Journals (Sweden)

    Sevim GÖNEN

    2017-10-01

    Full Text Available ABSTRACT BACKGROUND: As being the first bacteria determined to be carcinogenic, Helicobacter pylori (H. pylori is a pathogen localized in the stomach in more than half of the world population. Some earlier studies have found a relation between tissue histocompatibility antigens and gastric cancers depending on the regions. OBJECTIVE: The present study aimed to determine the distribution of human leukocyte antigen (HLA class I and class II antigens in H. pylori-positive pediatric patients with active gastritis and duodenal ulcer, excluding cancer cases, in our center. METHODS: The study included 40 patients diagnosed with H. pylori-positive active gastritis and duodenal ulcer and 100 controls consisting of healthy donor candidates. The HLA class I and class II antigens were studied in the isolated DNA samples using the polymerase chain reaction sequence-specific oligonucleotide probes. RESULTS: The frequency of HLA-B*51 antigen was significantly higher in the patient group than in the control group (40% vs 17%; P=0.003. There was no difference between the two groups in terms of the frequencies of HLA-A, HLA-C, HLA-DR, and HLA-DQ antigens. CONCLUSION: It was determined that HLA-B*51 plays a critical role in H. pylori infection.

  8. Increased expression of natural-killer-associated and activation antigens in multiple myeloma.

    Science.gov (United States)

    Gonzalez, M; San Miguel, J F; Gascon, A; Moro, M J; Hernandez, J M; Ortega, F; Jimenez, R; Guerras, L; Romero, M; Casanova, F

    1992-02-01

    The expression of both natural-killer (NK)-associated and activation antigens was studied by flow cytometry in the peripheral blood of 47 untreated multiple myeloma (MM) patients. A significant increase in both absolute and relative numbers of CD57 positive cells as well as in the proportion of CD16 and CD11b cells was observed in patients with MM, specially in those in early stages of the disease (clinical stages I and II), suggesting a possible surveillance mechanism in response to an emerging malignant clone. Additional double stainings showed that strong CD16+ NK cells coexpress the CD56, CD11b, and CD2 antigens, while they lacked CD3, CD5, and WT31 antigens. Moreover, the previously reported increase in CD8 cells present in MM would be mainly due to a subset of CD8 cells that coexpress the CD57 Ags. The expression of activation antigens, especially CD38, was increased in peripheral blood lymphocytes of MM patients, the differences reaching statistical significance both in absolute and relative numbers in those cases with high numbers of CD16 NK cells and thus suggesting that these cells are functionally activated. These results reveal the existence of an increase in NK and activated cells in the peripheral blood of myeloma patients that may reflect a host's immunological mechanism in an attempt to modulate tumor cell growth.

  9. Active Immunization with Lipopolysaccharide Pseudomonas Antigen for Chronic Pseudomonas Bronchopneumonia in Guinea Pigs

    OpenAIRE

    Pennington, James E.; Hickey, William F.; Blackwood, Linda L.; Arnaut, M. Amin

    1981-01-01

    Chronic respiratory infection with Pseudomonas aeruginosa is a leading clinical problem among patients with cystic fibrosis. Because antimicrobial agents are usually ineffective in eradicating these infections, additional therapeutic or prophylactic measures should be considered. In this study, an experimental guinea pig model of chronic Pseudomonas aeruginosa bronchopneumonia was utilized to determine whether active immunization with lipopolysaccharide (LPS) P. aeruginosa antigen may favorab...

  10. Induction of anergy or active suppression following oral tolerance is determined by antigen dosage.

    OpenAIRE

    Friedman, A; Weiner, H L

    1994-01-01

    Oral tolerance was generated to hen egg white lysozyme in the mouse or to guinea pig myelin basic protein in the rat by a low-dose (1 mg) or a high-dose (5-20 mg) feeding regimen. High doses of antigen induced tolerance characterized by anergy with little or no active suppression and increased secretion of interleukin 4 (IL-4). Anergy was shown by an increase in frequency of IL-2-secreting cells following culture in recombinant IL-2. Low doses of antigen induced tolerance characterized by ant...

  11. Accumulation of plasma cells in inflamed sites: effects of antigen, nonspecific microbial activators, and chronic inflammation.

    Science.gov (United States)

    Mallison, S M; Smith, J P; Schenkein, H A; Tew, J G

    1991-11-01

    Plasma cells are common in chronically inflamed sites, including periodontal lesions. The aim of this study was to determine which factors contribute to this local accumulation of plasma cells. Specifically, we sought to evaluate the effects of specific antigen and nonspecific activators from an infectious agent associated with chronic inflammation (Fusobacterium nucleatum, an organism prominent in chronic periodontal lesions) and the effect of the chronic inflammation itself. Chronic inflammation (14 to 17 days) was induced in horseradish peroxidase (HRP)-immune rabbits by subcutaneous injection of 50 microliters of sterile alum in several sites in their backs. Controls included sites injected with saline or more acute sites examined after 3 days of alum inflammation. Sites were challenged with HRP (the antigen), sonicated F. nucleatum (the nonspecific activator), or both together to see whether F. nucleatum has an adjuvant effect. Three days after challenge, HRP-specific antibody-forming cells (AFC) were enumerated after peroxidase histochemistry. In noninflamed sites or sites with acute inflammation, virtually no HRP-specific AFC were evident. In contrast, chronic inflammation alone was sufficient to elicit a specific AFC response (congruent to 10 cells per mm2). Addition of either F. nucleatum or HRP to the chronic lesion about doubled the number of HRP-specific AFC. However, a dramatic 8- to 15-fold (80 to 150/mm2) increase was seen in chronically inflamed sites challenged with antigen and activator together. Interestingly, the activator did not have this adjuvant effect in the acute sites or in normal skin. In short, accumulation of plasma cells in inflamed sites is promoted by chronic inflammation, activators of microbial origin, and specific antigen. This milieu can be expected to develop in some periodontal lesions and could help explain why gingival crevicular fluid from some sites may contain extraordinary levels of locally produced specific antibodies

  12. Very Late Pathological Responses to Cobalt-Chromium Everolimus-Eluting, Stainless Steel Sirolimus-Eluting, and Cobalt-Chromium Bare Metal Stents in Humans.

    Science.gov (United States)

    Mori, Hiroyoshi; Atmakuri, Dheeraj R; Torii, Sho; Braumann, Ryan; Smith, Samantha; Jinnouchi, Hiroyuki; Gupta, Anuj; Harari, Emanuel; Shkullaku, Melsi; Kutys, Robert; Fowler, David; Romero, Maria; Virmani, Renu; Finn, Aloke V

    2017-11-17

    The "very late" clinical outcomes for durable polymer drug-eluting stents and bare metal stents (BMSs) have been shown to be dissimilar in clinical studies. Conceptually, the long-term vascular compatibility of BMSs is still regarded to be superior to drug-eluting stents; however, no pathologic study to date has specifically addressed this issue. We evaluated the very late (≥1 year) pathologic responses to durable polymer drug-eluting stents (cobalt-chromium [CoCr] everolimus-eluting stents [EESs] and stainless steel sirolimus-eluting stents [SS-SESs]) versus BMSs (CoCr-BMSs). From the CVPath stent registry, we studied a total of 119 lesions (40 CoCr-EESs, 44 SS-SESs, 35 CoCr-BMSs) from 92 autopsy cases with a duration ranging from 1 to 5 years. Sections of stented coronary segments were pathologically analyzed. Inflammation score and the percentage of struts with giant cells were lowest in CoCr-EESs (median inflammation score: 0.6; median percentage of struts with giant cells: 3.8%) followed by CoCr-BMSs (median inflammation score: 1.3 [Pstents and may have implications for future stent design. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

  13. The potential interaction between ewe body condition score and nutrition during very late pregnancy and lactation on the performance of twin-bearing ewes and their lambs

    Directory of Open Access Journals (Sweden)

    L. M. Cranston

    2017-09-01

    Full Text Available Objective The present study aimed to determine the impact of ewe body condition score (BCS (over a range of 2.0 to 3.0 and nutritional treatments (consisting of differing herbage masses during very late pregnancy and lactation and their potential interaction on the performance of twin-bearing ewes and their lambs to weaning. Methods On day 142 of pregnancy, twin-bearing ewes with a BCS of 2.0, 2.5, or 3.0 were allocated to a “Moderate’ or ‘Unrestricted’ nutritional treatment until day 95 of lactation (weaning. The nutritional treatments aimed to achieve average herbage masses of 1,200 to 1,300 kg dry matter (DM/ha (Moderate and 1,500 to 1,800 kg DM/ha (Unrestricted. Results There were no three-way interactions between ewe BCS group, nutritional treatment and time for any ewe or lamb parameter. The nutritional treatments had no effect (p>0.05 on lamb birth or weaning weight. Lambs born to Moderate ewes had greater survival and total litter weight at weaning (p1,200 kg DM/ha during very late pregnancy and lactation.

  14. Protein quality, antigenicity, and antioxidant activity of soy-based foodstuffs.

    Science.gov (United States)

    Amigo-Benavent, Miryam; Silván, Jose Manuel; Moreno, Francisco Javier; Villamiel, Mar; Del Castillo, M Dolores

    2008-08-13

    Commercial soy-based foodstuffs, including beverages ( n = 15), cow's milk supplemented with soy isoflavones ( n = 1), snacks ( n = 1), and biscuits ( n = 2), were analyzed to find any link between alterations in protein quality, safety (antigenicity), functionality (antioxidant activity), and food processing. Protein content was analyzed by the Kjeldhal method and available lysine by OPA assay. Chromatographic (RP-HPLC) and electrophoretic (SDS-PAGE) protein profiles were obtained to monitor modifications in the structure of soy allergens. The antigenicity was estimated by immunoblotting against soy total antibodies. Total phenol content was measured by Folin-Ciocalteu, while peroxyl radical scavenging activity of the sample was determined by ORAC FL assay. Protein content did not differ of those declared by the producers. Lysine availability was higher in liquid soy beverages compared to that in other soy foodstuffs studied here. 7S and 11S soy allergens were detected by RP-HPLC and SDS-PAGE, respectively. Both data indicated changes in soy protein patterns due to processing of instant powdered soymilk, soy snacks, and biscuits. Immunoblotting assay showed modifications in the antigenic response of these foodstuffs based on soy, suggesting that their processing had altered the structure of soy allergens. RP-HPLC, SDS-PAGE, and immunoblotting resulted in adequate analytical approaches for detecting changes in protein structure due to processing and adulteration. Protein quality, antigenicity, and antioxidant activity of soy products can be affected as a function of the intensity of the thermal processing.

  15. Janus particles as artificial antigen-presenting cells for T cell activation.

    Science.gov (United States)

    Chen, Bo; Jia, Yilong; Gao, Yuan; Sanchez, Lucero; Anthony, Stephen M; Yu, Yan

    2014-01-01

    Here we show that the multifunctionality of Janus particles can be exploited for in vitro T cell activation. We engineer bifunctional Janus particles on which the spatial distribution of two ligands, anti-CD3 and fibronectin, mimics the "bull's eye" protein pattern formed in the membrane junction between a T cell and an antigen-presenting cell. Different levels of T cell activation can be achieved by simply switching the spatial distribution of the two ligands on the surfaces of the "bull's eye" particles. We find that the ligand pattern also affects clustering of intracellular proteins. This study demonstrates that anisotropic particles, such as Janus particles, can be developed as artificial antigen-presenting cells for modulating T cell activation.

  16. Signal transduction by HLA class II antigens expressed on activated T cells

    DEFF Research Database (Denmark)

    Ødum, Niels; Martin, P J; Schieven, G L

    1991-01-01

    Human T cells express HLA class II antigens upon activation. Although activated, class II+ T cells can present alloantigens under certain circumstances, the functional role of class II antigens on activated T cells remains largely unknown. Here, we report that cross-linking of HLA-DR molecules...... after cross-linking CD4. Ligation of CD4 and class II molecules generated a synergistic effect of the intracellular free Ca2+ concentration response that required an interaction between the molecules on the cell surface. Since class II is the natural ligand for CD4, the present data suggest that class...... expressed on allospecific, CD4+ T clones and cell lines can function as transduction elements that trigger rapid cellular responses including tyrosine phosphorylation of cellular proteins and mobilization of Ca2+ from internal stores. The proteins phosphorylated on tyrosine were distinct from those observed...

  17. Immunopathology of human schistosomiasis mansoni: II. NK activity and stimulation by specific antigen

    Directory of Open Access Journals (Sweden)

    L. K. Benarroch

    1988-12-01

    Full Text Available Sixteen S. mansoni infected and untreated patients (5 with recent infection and 11 with chronic disease were evaluated for their in vitro natural killer (NK activity against the NK sensitive target K562 cell line. NK levels in 9 out of 11 patients (82% with chronic disease were significantly lower (mean = 15 ± 6%,compared with patients recently infected (mean = 41 ± 9% p < 0.001 and with the control group (mean = 38 ± 13% p < 0.001. However, both patients and controls NK activity was stimulated by soluble adult worm antigens (SAWA, indicating that NK function even in the chronic stage of the infection is able to respond to the parasite antigens. These results suggest the possibility of NK cell participation as effector mechanism against S. mansoni.

  18. Mucosal-Associated Invariant T Cells: New Insights into Antigen Recognition and Activation

    Directory of Open Access Journals (Sweden)

    Xingxing Xiao

    2017-11-01

    Full Text Available Mucosal-associated invariant T (MAIT cells, a novel subpopulation of innate-like T cells that express an invariant T cell receptor (TCRα chain and a diverse TCRβ chain, can recognize a distinct set of small molecules, vitamin B metabolites, derived from some bacteria, fungi but not viruses, in the context of an evolutionarily conserved major histocompatibility complex-related molecule 1 (MR1. This implies that MAIT cells may play unique and important roles in host immunity. Although viral antigens are not recognized by this limited TCR repertoire, MAIT cells are known to be activated in a TCR-independent mechanism during some viral infections, such as hepatitis C virus and influenza virus. In this article, we will review recent works in MAIT cell antigen recognition, activation and the role MAIT cells may play in the process of bacterial and viral infections and pathogenesis of non-infectious diseases.

  19. Accumulation of plasma cells in inflamed sites: effects of antigen, nonspecific microbial activators, and chronic inflammation.

    OpenAIRE

    Mallison, S M; Smith, J. P.; Schenkein, H. A.; Tew, J G

    1991-01-01

    Plasma cells are common in chronically inflamed sites, including periodontal lesions. The aim of this study was to determine which factors contribute to this local accumulation of plasma cells. Specifically, we sought to evaluate the effects of specific antigen and nonspecific activators from an infectious agent associated with chronic inflammation (Fusobacterium nucleatum, an organism prominent in chronic periodontal lesions) and the effect of the chronic inflammation itself. Chronic inflamm...

  20. Kinetics of T cell-activation molecules in response to Mycobacterium tuberculosis antigens

    Directory of Open Access Journals (Sweden)

    Antas Paulo RZ

    2002-01-01

    Full Text Available The phenotypic features acquired subsequent to antigen-specific stimulation in vitro were evaluated by means of the kinetic expressions of CD69 and CD25 activation molecules on T lymphocytes and assayed by flow cytometry in response to PPD, Ag85B, and ferritin in PPD-positive healthy control individuals. In response to PHA, CD69 staining on both CD4+ and CD8+ T cells became initially marked after 4 h, peaked at 24 h, and quickly decreased after 120 h. For CD25, a latter expression was detected around 8 h, having increased after 96 h. As expected, the response rate to the mycobacterial antigens was much lower than that to the mitogen. Positive staining was high after 96 h for CD25 and after 24 h for CD69. CD69 expression was significantly enhanced (p < 0.05 on CD8+ as compared to CD4+ T cells. High levels were also found between 96-120 h. Regarding Ag85B, CD25+ cells were mostly CD4+ instead of CD8+ T cells. Moreover, in response to ferritin, a lower CD25 expression was noted. The present data will allow further characterization of the immune response to new mycobacterial-specific antigens and their evaluation for possible inclusion in developing new diagnostic techniques for tuberculosis as well in a new vaccine to prevent the disease.

  1. Bacteroides gingivalis antigens and bone resorbing activity in root surface fractions of periodontally involved teeth

    Energy Technology Data Exchange (ETDEWEB)

    Patters, M.R.; Landsberg, R.L.; Johansson, L.A.; Trummel, C.L.; Robertson, P.R. (Department of Periodontology, University of Connecticut, School of Dental Medicine, Farmington, Connecticut, U.S.A.)

    1982-01-01

    Bone resorbing activity and the presence of antigens of Bacteroides gingivalis were assessed in plaque, calculus, cementum, and dentin obtained from roots of teeth previously exposed to periodontitis. Each fraction was obtained by scaling the root surface. The fraction were extracted by stirring and sonication, and the soluble centrifuged, sterilized, dialyzed, and adjusted to equivalent protein concentrations. Cementum and dentin extracts from impacted teeth were prepared similarly and served as controls. Stimulation of bone resorption by each extract was assessed in organ cultures of fetal rat bones by measurement of release of previously-incorporated /sup 45/Ca from the bone into the medium. In some groups of teeth, calculus and cementum were treated with acid prior to scaling. Citric acid washes were recovered and dialyzed. An enzyme-linked immunosorbent assay (ELISA) was used to assess the extracts for the presence of antigens reactive with an antiserum to B. gingivalis. Significant stimulation of bone resorption was found in all calculus and periodontally-involved cementum preparations. ELISA showed significant levels of B.gingivalis antigens in plaque, calculus, and cementum of periodontally-involved teeth, but not in involved dentin nor in cementum or dentin of impact teeth. Treatment with citric acid removed essentially all B.gingivalis antigens from cementum but not calculus. The results suggest that substances which stimulate bone resorption and substances which react with B. gingivalis antiserum are present in surface plaque, calculus, and cementum or periodontally-involved teeth. These substances are not present in cementum and dentin of impacted teeth nor in dentin of periodontally-involved teeth. Treatment by both scaling and citric demineralization will remove most of these substances from cementum of teeth previously exposed to periodontitis.

  2. Artificial antigen presenting cell (aAPC) mediated activation and expansion of natural killer T cells.

    Science.gov (United States)

    East, James E; Sun, Wenji; Webb, Tonya J

    2012-12-29

    a fundamental requirement of NKT cell activation, antigen: CD1d-Ig complexes provide a reliable method to isolate, activate, and expand effector NKT cell populations.

  3. Epidemiology of Late and Very Late Onset Group B Streptococcal Disease: Fifteen-Year Experience From Two Australian Tertiary Pediatric Facilities.

    Science.gov (United States)

    Bartlett, Adam W; Smith, Ben; George, C R Robert; McMullan, Brendan; Kesson, Alison; Lahra, Monica M; Palasanthiran, Pamela

    2017-01-01

    Group B Streptococcus (GBS) is a recognized cause of sepsis and meningitis, particularly in infants. Early onset (LOD, 7-89 days) and very late onset disease (VLOD, ≥90 days) is less well understood. The aims of this study were to assess risk factors, presentation, management and outcome for GBS LOD and VLOD. Microbiology laboratory databases and hospital diagnostic coding for Sydney Children's Hospital and the Children's Hospital at Westmead were investigated for patients ≥7 days of age diagnosed with GBS bloodstream infection or meningitis from January 1, 2000 to December 31, 2014 (15 years). Subjects' medical records were reviewed to confirm diagnosis and analyze risk factors, presentation, management and outcome. Eighty-seven cases of LOD and 28 cases of VLOD were identified, including 49 cases of bloodstream infection and 66 cases of meningitis. No significant differences in risk factors or presentation were identified between LOD and VLOD. Patients with LOD were more likely to develop sequelae compared with VLOD [odds ratio (OR): 3, 95% confidence interval (CI): 1.03-8.77]. Female sex was the only significant risk factor identified for GBS meningitis (OR: 3.5, 95% CI: 1.5-8.1). GBS meningitis was significantly associated with neurodevelopmental impairment or death compared with bloodstream infection (OR: 30, 95% CI: 6.4-140.6). GBS LOD and VLOD are encountered in similar at-risk populations, with LOD associated with higher morbidity. Infants presenting with meningitis are at significantly higher risk of sequelae compared with bloodstream infection.

  4. Development of an Antigen-DNAzyme Based Probe for a Direct Antibody-Antigen Assay Using the Intrinsic DNAzyme Activity of a Daunomycin Aptamer

    Directory of Open Access Journals (Sweden)

    Noorsharmimi Omar

    2013-12-01

    Full Text Available G-Quadruplex (G-4 structures are formed when G-rich DNA sequences fold into intra- or intermolecular four-stranded structures in the presence of metal ions. G-4-hemin complexes are often effective peroxidase-mimicking DNAzymes that are applied in many detection systems. This work reports the application of a G-rich daunomycin-specific aptamer for the development of an antibody-antigen detection assay. We investigated the ability of the daunomycin aptamer to efficiently catalyze the hemin-dependent peroxidase activity independent of daunomycin. A reporter probe consisting of biotinylated antigen and daunomycin aptamer coupled to streptavidin gold nanoparticles was successfully used to generate a colorimetric readout. In conclusion, the daunomycin aptamer can function as a robust alternative DNAzyme for the development of colorimetric assays.

  5. Choroidal dendritic cells require activation to present antigen and resident choroidal macrophages potentiate this response.

    Science.gov (United States)

    Forrester, J V; Lumsden, L; Duncan, L; Dick, A D

    2005-03-01

    The uveal compartment of the eye contains extensive networks of resident macrophages and dendritic cells. These cells are now recognised to have a role in many ocular pathologies. The aim of this study was to isolate, characterise, and compare the function of ciliary body/choroid dendritic cells and macrophages from the normal eye. Explants of rat and human ciliary body/choroid were cultured in vitro for various periods of time and cells harvested either from the supernatant fluid or from enzyme digested and washed explants. The cells were then phenotyped by microscopy and flow cytometry, examined by video time lapse photomicroscopy, and analysed functionally in a series of immunoassays. Two main types of dendritic cell were identified: large veil-like MHC class II(mid) motile but relatively non-translocatory cells and small MHC class II(hi) motile and rapidly translocating cells. Tissue macrophages mainly remained associated with the explants in culture but gradually lost their resident tissue marker (ED2) and detached from the explants as clusters of low density, large, CR3 (ED7)(+) cells, some of which underwent apoptosis. Video time lapse studies showed dendritic cells constantly interacting with large single cells and cell clusters by traversing the interstices of the cell clusters. In functional studies, freshly isolated dendritic cells were poor presenters of antigen and required activation by short term culture for acquisition of antigen presenting function. In contrast, dendritic cell depleted choroidal cell preparations containing macrophages and other cells failed to present antigen even after short term culture but augmented the antigen presenting function of dendritic cells when tested in co-culture. At least two types of dendritic cells are present in the normal ciliary body/choroid layer of the eye. It is likely that these cells have different functions based on their motility and potential to migrate to secondary lymphoid tissue either during normal

  6. Particle shape dependence of CD8+ T cell activation by artificial antigen presenting cells.

    Science.gov (United States)

    Sunshine, Joel C; Perica, Karlo; Schneck, Jonathan P; Green, Jordan J

    2014-01-01

    Previous work developing particle-based acellular, artificial antigen presenting cells (aAPCs) has focused exclusively on spherical platforms. To explore the role of shape, we generated ellipsoidal PLGA microparticles with varying aspect ratios (ARs) and synthesized aAPCs from them. The ellipsoidal biomimetic aAPCs with high-AR showed significantly enhanced in vitro and in vivo activity above spherical aAPCs with particle volume and antigen content held constant. Confocal imaging indicates that CD8+ T cells preferentially migrate to and are activated by interaction with the long axis of the aAPC. Importantly, enhanced activity of high-AR aAPCs was seen in a mouse melanoma model, with high-AR aAPCs improving melanoma survival compared to non-cognate aAPCs (p = 0.004) and cognate spherical aAPCs (p = 0.05). These findings indicate that particle geometry is a critical design criterion in the generation of aAPCs, and may offer insight into the essential role of geometry in the interaction between CD8+ T cells and biological APCs. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. HIV-1 Activates T Cell Signaling Independently of Antigen to Drive Viral Spread.

    Science.gov (United States)

    Len, Alice C L; Starling, Shimona; Shivkumar, Maitreyi; Jolly, Clare

    2017-01-24

    HIV-1 spreads between CD4 T cells most efficiently through virus-induced cell-cell contacts. To test whether this process potentiates viral spread by activating signaling pathways, we developed an approach to analyze the phosphoproteome in infected and uninfected mixed-population T cells using differential metabolic labeling and mass spectrometry. We discovered HIV-1-induced activation of signaling networks during viral spread encompassing over 200 cellular proteins. Strikingly, pathways downstream of the T cell receptor were the most significantly activated, despite the absence of canonical antigen-dependent stimulation. The importance of this pathway was demonstrated by the depletion of proteins, and we show that HIV-1 Env-mediated cell-cell contact, the T cell receptor, and the Src kinase Lck were essential for signaling-dependent enhancement of viral dissemination. This study demonstrates that manipulation of signaling at immune cell contacts by HIV-1 is essential for promoting virus replication and defines a paradigm for antigen-independent T cell signaling. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  8. Incidence and predictors of very late (>or=4 years) major cardiac adverse events in the DESIRE (Drug-Eluting Stents in the Real World)-Late registry.

    Science.gov (United States)

    Costa, J Ribamar; Sousa, Amanda; Moreira, Adriana C; Costa, Ricardo A; Cano, Manuel; Maldonado, Galo; Campos, Cantídio; Carballo, Mariana; Pavanello, Ricardo; Sousa, J Eduardo

    2010-01-01

    Our aim was to access the incidence of late major adverse cardiac events (MACE) and stent thrombosis (ST) in nonselected, complex patients followed for a period >/=4 years. Despite the efficacy of drug-eluting stents (DES) in reducing repeated target lesion revascularization, concerns regarding the occurrence of late and very late ST have partially obscured the benefits of this novel technology. All consecutive patients treated solely with DES between May 2002 and January 2005 were enrolled into this prospective, nonrandomized, single-center registry. The primary end point was long-term occurrence of MACE up to 7 years. Independent predictors of MACE, cardiac death, target lesion revascularization, and ST were obtained by a multivariate Cox proportional hazards regression model. A total of 1,010 patients were enrolled. Most of them were men (77%) with a mean age of 63.7 years. Stent/patient rate was 1.4. Patients were kept in dual antiplatelet therapy for 3 and 6 months after Cypher (Cordis, Johnson & Johnson, Miami Lakes, Florida) and Taxus (Boston Scientific Corp., Natick, Massachusetts) stent implantation, respectively. Follow-up was obtained in 98.2% of the cohort (median 5.01 years). Survival free of MACE and cumulative incidence of definite/probable ST were 84.6% and 1.7%, respectively. Independent predictors of ST were percutaneous coronary intervention in the setting of acute myocardial infarction, DES overlapping, treatment of multivessel disease, presence of moderate-to-severe calcification at lesion site, and in-stent residual stenosis. The deployment of DES in complex, real-world patients resulted in a low rate of very long-term MACE and ST. However, ST still occurs very long after the index procedure. Copyright (c) 2010 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  9. Naive T lymphocytes traffic to inflamed central nervous system, but require antigen recognition for activation

    DEFF Research Database (Denmark)

    Krakowski, M L; Owens, T

    2000-01-01

    Organ-specific autoimmune diseases may be induced by infiltration of the target tissue by CD4(+) T cells with specificity for self antigen(s). As disease progresses, T cells of other specificities appear in the tissue. Traffic of naive, antigen-inexperienced T cells to target tissues has not been...

  10. Two step procedure for purification of enzymatically active prostate-specific antigen from seminal plasma.

    Science.gov (United States)

    Bindukumar, B; Kawinski, Elzbieta; Cherrin, Craig; Gambino, Leah M; Nair, Madhavan P N; Schwartz, Stanley A; Chadha, Kailash C

    2004-12-25

    The role of prostate-specific antigen (PSA) during the onset of prostate cancer and subsequent tumor growth and metastasis is not well understood. We have developed a simple two step procedure, based on principles of hydrophobic charge-induction chromatography and molecular size chromatography to provide pure free-PSA (f-PSA) preparation that is free from all other known PSA complexes as well as human kallikrein 2 (hK2). The overall recovery of f-PSA is 72%. The isolated f-PSA consists of three known isoforms that corresponds to pI of 6.2, 6.4 and 7.2. f-PSA is enzymatically active and its enzymatic activity can be effectively neutralized by a serine protease inhibitor.

  11. Vitamin D controls T cell antigen receptor signaling and activation of human T cells

    DEFF Research Database (Denmark)

    von Essen, Marina Rode; Kongsbak-Wismann, Martin; Schjerling, Peter

    2010-01-01

    Phospholipase C (PLC) isozymes are key signaling proteins downstream of many extracellular stimuli. Here we show that naive human T cells had very low expression of PLC-gamma1 and that this correlated with low T cell antigen receptor (TCR) responsiveness in naive T cells. However, TCR triggering...... led to an upregulation of approximately 75-fold in PLC-gamma1 expression, which correlated with greater TCR responsiveness. Induction of PLC-gamma1 was dependent on vitamin D and expression of the vitamin D receptor (VDR). Naive T cells did not express VDR, but VDR expression was induced by TCR...... signaling via the alternative mitogen-activated protein kinase p38 pathway. Thus, initial TCR signaling via p38 leads to successive induction of VDR and PLC-gamma1, which are required for subsequent classical TCR signaling and T cell activation....

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

    Directory of Open Access Journals (Sweden)

    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

  13. Butyrate and propionate inhibit antigen-specific CD8+ T cell activation by suppressing IL-12 production by antigen-presenting cells

    DEFF Research Database (Denmark)

    Nastasi, Claudia; Fredholm, Simon; Willerslev-Olsen, Andreas

    2017-01-01

    Short chain fatty acids (SCFAs), such as acetate, butyrate and propionate, are products of microbial macronutrients fermentation that distribute systemically and are believed to modulate host immune responses. Recent data have indicated that certain SCFAs, such as butyrate and propionate, directly...... modulate human dendritic cell (DC) function. Given the role of DCs in initiating and shaping the adaptive immune response, we now explore how SCFAs affect the activation of antigen-specific CD8+ T cells stimulated with autologous, MART1 peptide-pulsed DC. We show that butyrate reduces the frequency...... of peptide-specific CD8+ T cells and, together with propionate, inhibit the activity of those cells. On the contrary, acetate does not affect them. Importantly, butyrate and propionate inhibit the production of IL-12 and IL-23 in the DCs and exogenous IL-12 fully restores the activation of the MART-1...

  14. Minor antigen distribution predicts site-specific graft-versus-tumor activity of adoptively transferred, minor antigen-specific CD8 T Cells

    National Research Council Canada - National Science Library

    Shand, Jessica C; Qin, Haiying; Nasholm, Nicole; Capitini, Christian M; Fry, Terry J

    2014-01-01

    .... Although minor histocompatibility antigens (MiHA) represent promising targets, broad expression of these antigens has been associated with poor responses and T cell dysfunction that may not be prevented by targeting MiHA with limited expression...

  15. Functionally Active Fc Mutant Antibodies Recognizing Cancer Antigens Generated Rapidly at High Yields

    Directory of Open Access Journals (Sweden)

    Kristina M. Ilieva

    2017-09-01

    Full Text Available Monoclonal antibodies find broad application as therapy for various types of cancer by employing multiple mechanisms of action against tumors. Manipulating the Fc-mediated functions of antibodies that engage immune effector cells, such as NK cells, represents a strategy to influence effector cell activation and to enhance antibody potency and potentially efficacy. We developed a novel approach to generate and ascertain the functional attributes of Fc mutant monoclonal antibodies. This entailed coupling single expression vector (pVitro1 antibody cloning, using polymerase incomplete primer extension (PIPE polymerase chain reaction, together with simultaneous Fc region point mutagenesis and high yield transient expression in human mammalian cells. Employing this, we engineered wild type, low (N297Q, NQ, and high (S239D/I332E, DE FcR-binding Fc mutant monoclonal antibody panels recognizing two cancer antigens, HER2/neu and chondroitin sulfate proteoglycan 4. Antibodies were generated with universal mutagenic primers applicable to any IgG1 pVitro1 constructs, with high mutagenesis and transfection efficiency, in small culture volumes, at high yields and within 12 days from design to purified material. Antibody variants conserved their Fab-mediated recognition of target antigens and their direct anti-proliferative effects against cancer cells. Fc mutations had a significant impact on antibody interactions with Fc receptors (FcRs on human NK cells, and consequently on the potency of NK cell activation, quantified by immune complex-mediated calcium mobilization and by antibody-dependent cellular cytotoxicity (ADCC of tumor cells. This strategy for manipulation and testing of Fc region engagement with cognate FcRs can facilitate the design of antibodies with defined effector functions and potentially enhanced efficacy against tumor cells.

  16. Antigen-specific cytotoxic T cell and antigen-specific proliferating T cell clones can be induced to cytolytic activity by monoclonal antibodies against T3

    NARCIS (Netherlands)

    Spits, H.; Yssel, H.; Leeuwenberg, J.; de Vries, J. E.

    1985-01-01

    T3 is a human differentiation antigen expressed exclusively on mature T cells. In this study it is shown that anti-T3 monoclonal antibodies, in addition to their capacity to induce T cells to proliferate, are able to induce antigen-specific cytotoxic T lymphocyte clones to mediate antigen

  17. Activation of human natural killer cells by the novel innate immune modulator recombinant Eimeria antigen.

    Science.gov (United States)

    Aylsworth, Charles F; Aldhamen, Yasser A; Seregin, Sergey S; Godbehere, Sarah; Amalfitano, Andrea

    2013-08-01

    The safe and effective activation of the innate and adaptive immune systems are crucial in the implementation of immunotherapeutic modalities for the prevention and treatment of human diseases. Eimeria antigen (EA) and its recombinantly expressed analog (rEA) are extremely effective activators of innate immunity in mice. The effects of rEA in the mouse are primarily mediated through the TLR11/12 MyD88 signaling system. Human cells lack functional TLR11 and TLR12, suggesting that rEA would not be effective in providing beneficial immune activation in humans. In the current report we provide definitive evidence that the treatment of human peripheral blood mononuclear cell (PBMC) cultures with rEA significantly up regulates CD69, CD107, NKG2D levels on NK cells. Furthermore, rEA stimulates human NK cell effector functions including increasing intracellular levels of IFNγ and Granzyme B. These responses are positively correlated with an improved capacity of rEA stimulated human PBMCs to kill NK cell-sensitive human K562 tumor cells. Importantly, rEA-triggered innate immune responses was not associated with increased pro-inflammatory cytokines and chemokines production. These data confirm a previously unidentified role for rEA in human immune cell activation, and suggests the utilization of rEA in immunotherapies against a variety of infectious diseases and cancers. Copyright © 2013 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.

  18. Vaccine adjuvant MF59 promotes the intranodal differentiation of antigen-loaded and activated monocyte-derived dendritic cells.

    Directory of Open Access Journals (Sweden)

    Rossella Cioncada

    Full Text Available MF59 is an oil-in-water emulsion adjuvant approved for human influenza vaccination in European Union. The mode of action of MF59 is not fully elucidated yet, but results from several years of investigation indicate that MF59 establishes an immunocompetent environment at injection site which promotes recruitment of immune cells, including antigen presenting cells (APCs, that are facilitated to engulf antigen and transport it to draining lymph node (dLN where the antigen is accumulated. In vitro studies showed that MF59 promotes the differentiation of monocytes to dendritic cells (Mo-DCs. Since after immunization with MF59, monocytes are rapidly recruited both at the injection site and in dLN and appear to have a morphological change toward a DC-like phenotype, we asked whether MF59 could play a role in inducing differentiation of Mo-DC in vivo. To address this question we immunized mice with the auto-fluorescent protein Phycoerythrin (PE as model antigen, in presence or absence of MF59. We measured the APC phenotype and their antigen uptake within dLNs, the antigen distribution within the dLN compartments and the humoral response to PE. In addition, using Ovalbumin as model antigen, we measured the capacity of dLN APCs to induce antigen-specific CD4 T cell proliferation. Here, we show, for the first time, that MF59 promotes differentiation of Mo-DCs within dLNs from intranodal recruited monocytes and we suggest that this differentiation could take place in the medullary compartment of the LN. In addition we show that the Mo-DC subset represents the major source of antigen-loaded and activated APCs within the dLN when immunizing with MF59. Interestingly, this finding correlates with the enhanced triggering of antigen-specific CD4 T cell response induced by LN APCs. This study therefore demonstrates that MF59 is able to promote an immunocompetent environment also directly within the dLN, offering a novel insight on the mechanism of action of

  19. Soluble Expression and Characterization of Biologically Active Bacillus anthracis Protective Antigen in Escherichia coli

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    Nagendra Suryanarayana

    2016-01-01

    Full Text Available Bacillus anthracis secretory protein protective antigen (PA is primary candidate for subunit vaccine against anthrax. Attempts to obtain large quantity of PA from Escherichia coli expression system often result in the formation of insoluble inclusion bodies. Therefore, it is always better to produce recombinant proteins in a soluble form. In the present study, we have obtained biologically active recombinant PA in small scale E. coli shake culture system using three different expression constructs. The PA gene was cloned in expression vectors bearing trc, T5, and T7 promoters and transformed into their respective E. coli hosts. The growth conditions were optimized to obtain maximum expression of PA in soluble form. The expression construct PA-pET32c in DE3-pLysS E. coli host resulted in a maximum production of soluble PA (15 mg L−1 compared to other combinations. Purified PA was subjected to trypsin digestion and binding assay with lethal factor to confirm the protein’s functionality. Biological activity was confirmed by cytotoxicity assay on J774.1 cells. Balb/c mice were immunized with PA and the immunogenicity was tested by ELISA and toxin neutralization assay. This study highlights the expression of soluble and biologically active recombinant PA in larger quantity using simpler E. coli production platform.

  20. Cross-presentation of viral antigens in dribbles leads to efficient activation of virus-specific human memory T cells.

    Science.gov (United States)

    Ye, Wei; Xing, Yun; Paustian, Christopher; van de Ven, Rieneke; Moudgil, Tarsem; Hilton, Traci L; Fox, Bernard A; Urba, Walter J; Zhao, Wei; Hu, Hong-Ming

    2014-04-16

    Autophagy regulates innate and adaptive immune responses to pathogens and tumors. We have reported that autophagosomes derived from tumor cells after proteasome inhibition, DRibbles (Defective ribosomal products in blebs), were excellent sources of antigens for efficient cross priming of tumor-specific CD8⁺ T cells, which mediated regression of established tumors in mice. But the activity of DRibbles in human has not been reported. DRibbles or cell lysates derived from HEK293T or UbiLT3 cell lines expressing cytomegalovirus (CMV) pp65 protein or transfected with a plasmid encoding dominant HLA-A2 restricted CMV, Epstein-Barr virus (EBV), and Influenza (Flu) epitopes (CEF) were loaded onto human monocytes or PBMCs and the response of human CMV pp65 or CEF antigen-specific CD4⁺ and CD8⁺ memory T cells was detected by intracellular staining. The effect of cytokines (GM-CSF, IL-4, IL-12, TNF-α, IFN-α and IFN-γ) TLR agonists (Lipopolysaccharide, Polyinosinic-polycytidylic acid (poly(I:C), M52-CpG, R848, TLR2 ligand) and CD40 ligand on the cross-presentation of antigens contained in DRibbles or cell lysates was explored. In this study we showed that purified monocytes, or human PBMCs, loaded with DRibbles isolated from cells expressing CMV or CEF epitopes, could activate CMV- or CEF-specific memory T cells. DRibbles were significantly more efficient at stimulating CD8⁺ memory T cells compared to cell lysates expressing the same antigenic epitopes. We optimized the conditions for T-cell activation and IFN-γ production following direct loading of DRibbles onto PBMCs. We found that the addition of Poly(I:C), CD40 ligand, and GM-CSF to the PBMCs together with DRibbles significantly increased the level of CD8⁺ T cell responses. DRibbles containing specific viral antigens are an efficient ex vivo activator of human antigen-specific memory T cells specific for those antigens. This function could be enhanced by combining with Poly(I:C), CD40 ligand, and GM

  1. Longitudinal microarray analysis of cell surface antigens on peripheral blood mononuclear cells from HIV+ individuals on highly active antiretroviral therapy

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    Wang Bin

    2008-03-01

    Full Text Available Abstract Background The efficacy of highly active antiretroviral therapy (HAART determined by simultaneous monitoring over 100 cell-surface antigens overtime has not been attempted. We used an antibody microarray to analyze changes in the expression of 135 different cell-surface antigens overtime on PBMC from HIV+ patients on HAART. Two groups were chosen, one (n = 6 achieved sustainable response by maintaining below detectable plasma viremia and the other (n = 6 responded intermittently. Blood samples were collected over an average of 3 years and 5–8 time points were selected for microarray assay and statistical analysis. Results Significant trends over time were observed for the expression of 7 cell surface antigens (CD2, CD3epsilon, CD5, CD95, CD36, CD27 and CD28 for combined patient groups. Between groups, expression levels of 10 cell surface antigens (CD11a, CD29, CD38, CD45RO, CD52, CD56, CD57, CD62E, CD64 and CD33 were found to be differential. Expression levels of CD9, CD11a, CD27, CD28 and CD52, CD44, CD49d, CD49e, CD11c strongly correlated with CD4+ and CD8+ T cell counts, respectively. Conclusion Our findings not only detected markers that may have potential prognostic/diagnostic values in evaluating HAART efficacy, but also showed how density of cell surface antigens could be efficiently exploited in an array-like manner in relation to HAART and HIV-infection. The antigens identified in this study should be further investigated by other methods such as flow cytometry for confirmation as biological analysis of these antigens may help further clarify their role during HAART and HIV infection.

  2. Hepatitis B virus e antigen induces activation of rat hepatic stellate cells

    Energy Technology Data Exchange (ETDEWEB)

    Zan, Yanlu [Center for Molecular Virology, CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Zhang, Yuxia, E-mail: yzhang@wehi.edu.au [Center for Molecular Virology, CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101 (China); Tien, Po, E-mail: tienpo@sun.im.ac.cn [Center for Molecular Virology, CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101 (China)

    2013-06-07

    Highlights: •HBeAg expression in HSCs induced production of ECM protein and liver fibrotic markers. •The activation and proliferation of HSCs were mediated by TGF-β. •HBeAg protein purified from cell medium directly activated HSCs. -- Abstract: Chronic hepatitis B virus infection is a major cause of hepatic fibrosis, leading to liver cirrhosis and hepatocellular carcinoma. Hepatitis B virus e antigen (HBeAg) is an accessory protein of HBV, not required for viral replication but important for natural infection in vivo. Hepatic stellate cells (HSCs) are the major producers of excessive extracellular matrix during liver fibrogenesis. Therefore, we examined the influence of HBeAg on HSCs. The rat HSC line HSC-T6 was transfected with HBeAg plasmids, and expression of α-smooth muscle actin, collagen I, transforming growth factor-β1 (TGF-β), and tissue inhibitors of metalloproteinase 1 (TIMP-1) was investigated by quantitative real-time PCR. The proliferation of HSCs was determined by MTS analysis. HBeAg transduction induced up-regulation of these fibrogenic genes and proliferation of HSCs. We found that HBeAg induced TGF-β secretion in HSCs, and the activation of HSCs was prevented by a neutralizing anti-TGF-β antibody. Depletion and addition of HBeAg protein in conditioned medium from HSC-T6 cells transduced with HBeAg indicated that HBeAg directly induced the activation and proliferation of rat primary HSCs. Taken together, HBeAg induces the activation and proliferation of HSCs, mainly mediated by TGF-β, and HBeAg protein purified from cell medium can directly activate HSCs.

  3. A cytoplasmic activator of DNA replication is involved in signal transduction in antigen-specific T cell lines.

    Science.gov (United States)

    Wong, R L; Clark, R B; Gutowski, J K; Katz, M E; Fresa, K L; Cohen, S

    1990-05-01

    Cytoplasmic extracts prepared from T cell lines undergoing antigen-specific, interleukin-2 (IL-2)-dependent proliferation were tested for their ability to induce DNA synthesis in isolated, quiescent nuclei. A tetanus toxoid (TET)-specific T cell line, established from peripheral blood of a normal human volunteer, was stimulated in the presence of relevant antigen and 1 unit/ml IL-2. Cytoplasmic extracts prepared from these cells were capable of inducing DNA synthesis in isolated, quiescent nuclei. The ability of cytoplasmic extracts to induce DNA synthesis in isolated, quiescent nuclei. The ability of cytoplasmic extracts to induce DNA synthesis in isolated nuclei correlated positively with the degree of proliferation induced in these cells. In contrast, incubation of this T cell line in the absence of antigen failed to induce proliferation and cytoplasmic extracts prepared from these cells induced little to no DNA synthesis in isolated, quiescent nuclei. The factor present in the cytoplasm of T cells stimulated with relevant antigen in the presence of IL-2 is similar, if not identical, to a factor which we have previously demonstrated in cytoplasmic extracts prepared from transformed lymphoblastoid cell lines and from mitogenically stimulated normal human peripheral blood mononuclear cells. This factor, which we have called activator of DNA replication (ADR) is a heat-labile protein, and is inactivated by treatment with protease inhibitors, including aprotinin. The ability of cytoplasmic extracts from T cells undergoing antigen-specific, IL-2-dependent proliferation to induce DNA synthesis in isolated, quiescent nuclei was markedly inhibited in the presence of aprotinin, providing strong evidence that a cytoplasmic activator of DNA replication, ADR, is involved in the signal transduction process for antigen-specific, IL-2-dependent T cell proliferation. ADR may represent a common intracellular mediator of DNA synthesis in activated and transformed lymphocytes.

  4. The Rickettsia Surface Cell Antigen 4 Applies Mimicry to Bind to and Activate Vinculin*

    Science.gov (United States)

    Park, HaJeung; Lee, Jun Hyuck; Gouin, Edith; Cossart, Pascale; Izard, Tina

    2011-01-01

    Pathogenic Rickettsia species cause high morbidity and mortality, especially R. prowazekii, the causative agent of typhus. Like many intracellular pathogens, Rickettsia exploit the cytoskeleton to enter and spread within the host cell. Here we report that the cell surface antigen sca4 of Rickettsia co-localizes with vinculin in cells at sites of focal adhesions in sca4-transfected cells and that sca4 binds to and activates vinculin through two vinculin binding sites (VBSs) that are conserved across all Rickettsia. Remarkably, this occurs through molecular mimicry of the vinculin-talin interaction that is also seen with the IpaA invasin of the intracellular pathogen Shigella, where binding of these VBSs to the vinculin seven-helix bundle head domain (Vh1) displaces intramolecular interactions with the vinculin tail domain that normally clamp vinculin in an inactive state. Finally, the vinculin·sca4-VBS crystal structures reveal that vinculin adopts a new conformation when bound to the C-terminal VBS of sca4. Collectively, our data define the mechanism by which sca4 activates vinculin and interacts with the actin cytoskeleton, and they suggest important roles for vinculin in Rickettsia pathogenesis. PMID:21841197

  5. Preparation, Characterization, and Determination of Immunological Activities of Transfer Factor Specific to Human Sperm Antigen

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    Jianwei Zhou

    2013-01-01

    Full Text Available Objective. The objective of this study was to prepare, characterize, and determine immunological activities of specific transfer factor (STF specific to human sperm antigen (HSA for the preparation of antisperm contraceptive vaccine that can be used as an immunocontraceptive. Methods. HSA-STF was prepared using the spleens of rabbits vaccinated with HSA. The specific immunological activities were examined by lymphocyte proliferation test (LPT, leukocyte adhesion inhibition test (LAIT, and by determining the concentrations of IL-4, γ-IFN, and IL-21. HSA-STF was a helveolous substance, having a pH value of 7.0±0.4 and UV absorption maxima at 258 ± 6 nm. It contained seventeen amino acids; glycine and glutamic acids were the highest in terms of concentrations (38.8 μg/mL and 36.3 μg/mL, resp.. Results. The concentration of polypeptide was 2.34±0.31 mg/mL, and ribose was 0.717±0.043 mg/mL. The stimulation index for lymphocyte proliferation test was 1.84, and the leukocyte adhesion inhibition rate was 37.7%. There was a statistically significant difference between the cultural lymphocytes with HSA-STF and non-HSA-STF for γ-IFN and IL-21 (P0.05. Conclusion. HSA-STF was prepared and characterized successfully. It had immunological activity which could transfer the immune response specific to HSA and prove to be a potential candidate for the development of male immunocontraceptive agents.

  6. Preparation, characterization, and determination of immunological activities of transfer factor specific to human sperm antigen.

    Science.gov (United States)

    Zhou, Jianwei; Kong, Cui; Yuan, Zhaohong; Luo, Junmin; Ma, Rui; Yu, Jiang; Cao, Jinghe

    2013-01-01

    OBJECTIVE. The objective of this study was to prepare, characterize, and determine immunological activities of specific transfer factor (STF) specific to human sperm antigen (HSA) for the preparation of antisperm contraceptive vaccine that can be used as an immunocontraceptive. METHODS. HSA-STF was prepared using the spleens of rabbits vaccinated with HSA. The specific immunological activities were examined by lymphocyte proliferation test (LPT), leukocyte adhesion inhibition test (LAIT), and by determining the concentrations of IL-4, γ -IFN, and IL-21. HSA-STF was a helveolous substance, having a pH value of 7.0 ± 0.4 and UV absorption maxima at 258 ± 6 nm. It contained seventeen amino acids; glycine and glutamic acids were the highest in terms of concentrations (38.8 μ g/mL and 36.3 μ g/mL, resp.). RESULTS. The concentration of polypeptide was 2.34 ± 0.31 mg/mL, and ribose was 0.717 ± 0.043 mg/mL. The stimulation index for lymphocyte proliferation test was 1.84, and the leukocyte adhesion inhibition rate was 37.7%. There was a statistically significant difference between the cultural lymphocytes with HSA-STF and non-HSA-STF for γ -IFN and IL-21 (P 0.05). CONCLUSION. HSA-STF was prepared and characterized successfully. It had immunological activity which could transfer the immune response specific to HSA and prove to be a potential candidate for the development of male immunocontraceptive agents.

  7. Plasmodium falciparum acid basic repeat antigen (ABRA) peptides: erythrocyte binding and biological activity.

    Science.gov (United States)

    Curtidor, H; Urquiza, M; Suarez, J E; Rodriguez, L E; Ocampo, M; Puentes, A; Garcia, J E; Vera, R; Lopéz, R; Ramirez, L E; Pinzon, M; Patarroyo, M E

    2001-08-14

    Non overlapping 20-mer peptides, covering the complete sequence of acid basic repeat antigen (ABRA) of Plasmodium falciparum, were synthesised and tested in binding assays to erythrocytes. Five peptides localised in the N-terminal region coded 2148 (121LQSHKKLIKALKKNIESYQN(140)), 2149 (141KKHLIYKNKSYNPLLLSCVK(160)), 2150 (161KMNMLKENVDYIQKNQNLFK(180)), 2152 (201YKSQGHKKETSQNQNENNDN(220)) and 2153 (221QKYQEVNDEDDVNDEEDTND(240)) specifically bind to erythrocytes. These peptides bind independently of the peptide and erythrocyte charge, with high affinity (Kd between 70 and 180 nM) and the hydrophobic interaction is important for this binding ( approximately 30% hydrophobic critical residues). These results allow us define a specific erythrocyte binding region (residues 121-240), which may bound to at least three different binding sites on erythrocytes. Peptide 2153 shares the underlined sequence 221QKYQEVNDEDDVNDEEDTND(240) with an earlier 18-mer peptide recognised by human exposed sera. Peptides number 2148 and 2149 in vitro inhibit erythrocyte invasion by merozoites. We found that 2149 peptide and some of its glycine analogues show specific haemolytic and/or antimicrobial activity. We discuss a possible role of ABRA or its regions in the merozoite invasion of erythrocyte.

  8. Plant virus particles carrying tumour antigen activate TLR7 and Induce high levels of protective antibody.

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    Jantipa Jobsri

    Full Text Available Induction of potent antibody is the goal of many vaccines targeted against infections or cancer. Modern vaccine designs that use virus-like particles (VLP have shown efficacy for prophylactic vaccination against virus-associated cancer in the clinic. Here we used plant viral particles (PVP, which are structurally analogous to VLP, coupled to a weak idiotypic (Id tumour antigen, as a conjugate vaccine to induce antibody against a murine B-cell malignancy. The Id-PVP vaccine incorporates a natural adjuvant, the viral ssRNA, which acts via TLR7. It induced potent protective anti-Id antibody responses in an in vivo mouse model, superior to the "gold standard" Id vaccine, with prevalence of the IgG2a isotype. Combination with alum further increased antibody levels and maintained the IgG2a bias. Engagement of TLR7 in vivo was followed by secretion of IFN-α by plasmacytoid dendritic cells and by activation of splenic CD11chi conventional dendritic cells. The latter was apparent from up-regulation of co-stimulatory molecules and from secretion of a wide range of inflammatory cytokines and chemokines including the Th1-governing cytokine IL-12, in keeping with the IgG2a antibody isotype distribution. PVP conjugates are a novel cancer vaccine design, offering an attractive molecular form, similar to VLP, and providing T-cell help. In contrast to VLP, they also incorporate a safe "in-built" ssRNA adjuvant.

  9. Production of immunologically active surface antigens of hepatitis B virus by Escherichia coli.

    Science.gov (United States)

    MacKay, P; Pasek, M; Magazin, M; Kovacic, R T; Allet, B; Stahl, S; Gilbert, W; Schaller, H; Bruce, S A; Murray, K

    1981-01-01

    Several plasmids have been constructed which direct the synthesis of hepatitis B virus surface antigens in Escherichia coli either as the native polypeptide or fused to other plasmid encoded polypeptides. When injected into rabbits, extracts from bacteria carrying some of these plasmids induced the synthesis of antibodies to the antigens even though the extracts did not give satisfactory positive results in radioimmunoassay for them. Either the NH2-terminal segment or the COOH-terminal segment of the surface antigens alone was sufficient to elicit the immune response, but antibodies against the two segments showed different specificities. The results emphasize the value of an in vivo assay for the presence of antigens in crude cell extracts and illustrate the feasibility of this type of screening with laboratory animals. PMID:6170067

  10. Taenia crassiceps Antigens Control Experimental Type 1 Diabetes by Inducing Alternatively Activated Macrophages

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    Arlett Espinoza-Jiménez

    2017-01-01

    Full Text Available Type 1 diabetes (T1D is an autoimmune disease caused by the selective destruction of the pancreatic β-cells, causing inability to produce insulin. Proinflammatory cytokines such as IL-1β, IL-6, TNF-α, IFN-γ, IL-12, IL-17, and NO can be released by CD4 and CD8+ lymphocytes as well as by classically activated macrophages (CAMϕs, which are important in the development of T1D. Helminth infections have been shown to prevent T1D, mainly through Th2-biased responses and increased recruitment of regulatory cell populations. Previously, we have shown that Taenia crassiceps infection in mice significantly reduces hyperglycemia, insulitis, and the incidence of T1D. In this study, we determined whether T. crassiceps-derived products such as soluble (TcS or excreted/secreted (TcES antigens might have a beneficial influence on the development of experimental T1D. Treatment with different doses before or after induction of T1D was analyzed. Mice that were pretreated with TcS were unable to develop T1D, whereas those receiving TcES early after T1D induction displayed significantly reduced insulitis and hyperglycemia along with increased recruitment of alternatively activated macrophages (AAMϕs and myeloid-derived suppressor cells (MDSCs. Finally, we examined the modulatory role of AAMϕs on T1D by depleting macrophages with clodronate-loaded liposomes, demonstrating that AAMϕs are key cells in T1D regulation.

  11. Comparative analysis of activation induced marker (AIM assays for sensitive identification of antigen-specific CD4 T cells.

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    Samantha Reiss

    Full Text Available The identification and study of antigen-specific CD4 T cells, both in peripheral blood and in tissues, is key for a broad range of immunological research, including vaccine responses and infectious diseases. Detection of these cells is hampered by both their rarity and their heterogeneity, in particular with regards to cytokine secretion profiles. These factors prevent the identification of the total pool of antigen-specific CD4 T cells by classical methods. We have developed assays for the highly sensitive detection of such cells by measuring the upregulation of surface activation induced markers (AIM. Here, we compare two such assays based on concurrent expression of CD69 plus CD40L (CD154 or expression of OX40 plus CD25, and we develop additional AIM assays based on OX40 plus PD-L1 or 4-1BB. We compare the relative sensitivity of these assays for detection of vaccine and natural infection-induced CD4 T cell responses and show that these assays identify distinct, but overlapping populations of antigen-specific CD4 T cells, a subpopulation of which can also be detected on the basis of cytokine synthesis. Bystander activation had minimal effect on AIM markers. However, some T regulatory cells upregulate CD25 upon antigen stimulation. We therefore validated AIM assays designed to exclude most T regulatory cells, for both human and non-human primate (NHP, Macaca mulatta studies. Overall, through head-to-head comparisons and methodological improvements, we show that AIM assays represent a sensitive and valuable method for the detection of antigen-specific CD4 T cells.

  12. Tumor Expression of the Carcinoembryonic Antigen Correlates with High Mitotic Activity and Cell Pleomorphism Index in Lung Carcinoma

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    Rancés Blanco

    2013-01-01

    Full Text Available At present, some research efforts are focusing on the evaluation of a variety of tumor associated antigens (TAAs for a better understanding of tumor biology and genetics of lung tumors. For this reason, we evaluated the tissue expression of carcinoembryonic antigen (CEA and ior C2 (a cell surface O-linked glycoprotein carbohydrate chain TAA in lung carcinomas, as well as its correlation with a variety of clinicopathological features. The tissue expression of CEA was evidenced in 22/43 (51.16% lung carcinomas and it was correlated with mitotic activity, cell pleomorphism indexes, and age of patients. The expression of ior C2 was observed in 15/43 (34.88% tumors but no correlation with the clinicopathological features mentioned above was obtained. No correlation between both CEA and ior C2 antigens expression and the overall survival (OS of non-small-cell lung cancer patients was also observed. However, CEA-negative patients displayed higher OS rates as compared with positive ones (69.74 versus 58.26 months. Our results seem to be in agreement with the role of CEA expression in tumor cell proliferation, inhibition of cell polarizations and tissue architecture distortion. The significance of ior C2 antigen in these malignancies and it potential use in diagnosis, prognosis, and/or immunotherapy must be reevaluated.

  13. Peptide vaccines prevent tumor growth by activating T cells that respond to native tumor antigens.

    Science.gov (United States)

    Jordan, Kimberly R; McMahan, Rachel H; Kemmler, Charles B; Kappler, John W; Slansky, Jill E

    2010-03-09

    Peptide vaccines enhance the response of T cells toward tumor antigens and represent a strategy to augment antigen-independent immunotherapies of cancer. However, peptide vaccines that include native tumor antigens rarely prevent tumor growth. We have assembled a set of peptide variants for a mouse-colon tumor model to determine how to improve T-cell responses. These peptides have similar affinity for MHC molecules, but differ in the affinity of the peptide-MHC/T-cell receptor interaction with a tumor-specific T-cell clone. We systematically demonstrated that effective antitumor responses are generated after vaccination with variant peptides that stimulate the largest proportion of endogenous T cells specific for the native tumor antigen. Importantly, we found some variant peptides that strongly stimulated a specific T-cell clone in vitro, but elicited fewer tumor-specific T cells in vivo, and were not protective. The T cells expanded by the effective vaccines responded to the wild-type antigen by making cytokines and killing target cells, whereas most of the T cells expanded by the ineffective vaccines only responded to the peptide variants. We conclude that peptide-variant vaccines are most effective when the peptides react with a large responsive part of the tumor-specific T-cell repertoire.

  14. Sperm antigens in fertilization.

    Science.gov (United States)

    Saling, P M

    1990-02-01

    A review of sperm antigens involved in fertilization includes a description of sperm differentiation, seminal fluid components that coat sperm, sperm antigens involved in binding to the zona pellucida (ZP), antigens involved in the acrosome reaction, in zona pellucida penetration, and those active in fusion with the ova membrane. Sperm antigens are located in certain domains of the cell, and they are altered during capacitation and passage through the female tract. Caltrin and acrosome-stabilizing factor are applied by seminal fluid. At least 2 antigens have been studied that occur in sterile women, although one cross reacts with milk proteins. Some antigens active in ZP binding are trypsin, proacrosin, acrosin, PH-20 from guinea pigs, and rabbit sperm autoantigen I. Antigens involved in the acrosome reaction, such as M42, are likely to cross react with other body proteins that also entail exocytosis. A mouse antigen involved in ZP penetration, MS 207 is well characterized. PH-30 from guinea pigs and M29 from mouse participate in sperm-egg membrane fusion, as does fertilization antigen I from human and mouse sperm which is know to cause infertility. Oddly, patients' sera react with polymers but not monomers of this antigen. Studies with antisperm antibodies suggest that it will not be necessary to agglutinate all sperm to block fertility, only to inhibit a single sperm epitope and function. It will probably be feasible to inhibit multiple successive events, and possibly to induce temporary immunity.

  15. Plant Virus Particles Carrying Tumour Antigen Activate TLR7 and Induce High Levels of Protective Antibody

    Science.gov (United States)

    Jobsri, Jantipa; Allen, Alex; Rajagopal, Deepa; Shipton, Michael; Kanyuka, Kostya; Lomonossoff, George P.; Ottensmeier, Christian; Diebold, Sandra S.; Stevenson, Freda K.; Savelyeva, Natalia

    2015-01-01

    Induction of potent antibody is the goal of many vaccines targeted against infections or cancer. Modern vaccine designs that use virus-like particles (VLP) have shown efficacy for prophylactic vaccination against virus-associated cancer in the clinic. Here we used plant viral particles (PVP), which are structurally analogous to VLP, coupled to a weak idiotypic (Id) tumour antigen, as a conjugate vaccine to induce antibody against a murine B-cell malignancy. The Id-PVP vaccine incorporates a natural adjuvant, the viral ssRNA, which acts via TLR7. It induced potent protective anti-Id antibody responses in an in vivo mouse model, superior to the “gold standard” Id vaccine, with prevalence of the IgG2a isotype. Combination with alum further increased antibody levels and maintained the IgG2a bias. Engagement of TLR7 in vivo was followed by secretion of IFN-α by plasmacytoid dendritic cells and by activation of splenic CD11chi conventional dendritic cells. The latter was apparent from up-regulation of co-stimulatory molecules and from secretion of a wide range of inflammatory cytokines and chemokines including the Th1-governing cytokine IL-12, in keeping with the IgG2a antibody isotype distribution. PVP conjugates are a novel cancer vaccine design, offering an attractive molecular form, similar to VLP, and providing T-cell help. In contrast to VLP, they also incorporate a safe “in-built” ssRNA adjuvant. PMID:25692288

  16. Caspase-1 Dependent IL-1β Secretion and Antigen-Specific T-Cell Activation by the Novel Adjuvant, PCEP

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    Sunita Awate

    2014-06-01

    Full Text Available The potent adjuvant activity of the novel adjuvant, poly[di(sodiumcarboxylatoethylphenoxyphosphazene] (PCEP, with various antigens has been reported previously. However, very little is known about its mechanisms of action. We have recently reported that intramuscular injection of PCEP induces NLRP3, an inflammasome receptor gene, and inflammatory cytokines, including IL-1β and IL-18, in mouse muscle tissue. Caspase-1 is required for the processing of pro-forms of IL-1β and IL-18 into mature forms and is a critical constituent of the NLRP3 inflammasome. Hence, in the present study, we investigated the role of caspase-1 in the secretion of IL-1β and IL-18 in PCEP-stimulated splenic dendritic cells (DCs. Caspase inhibitor YVAD-fmk-treated splenic DCs showed significantly reduced IL-1β and IL-18 secretion in response to PCEP stimulation. Further, PCEP had no effect on the expression of MHC class II or co-stimulatory molecules, CD86 and CD40, suggesting that PCEP does not induce DC maturation. However, PCEP directly activated B-cells to induce significant production of IgM. In addition, PCEP+ovalbumin (OVA immunized mice showed significantly increased production of antigen-specific IFN-γ by CD4+ and CD8+ T-cells. We conclude that PCEP activates innate immunity, leading to increased antigen-specific T-cell responses.

  17. Classical and nonclassical HLA class I antigen and NK Cell-activating ligand changes in malignant cells: current challenges and future directions.

    Science.gov (United States)

    Chang, Chien-Chung; Campoli, Michael; Ferrone, Soldano

    2005-01-01

    Changes in classical and nonclassical HLA class I antigen and NK cell-activating ligand expression have been identified in malignant lesions. These changes, which are described in this chapter, are believed to play a major role in the clinical course of the disease since both HLA class I antigens and NK cell-activating ligands are critical to the interaction between tumor cells and components of both innate and adaptive immune systems. Nevertheless, there is still debate in the literature about the biologic and functional significance of HLA class I antigen and NK cell-activating ligand abnormalities in malignant lesions. The reasons for this debate are reviewed. They include (i) the incomplete association between classical HLA class I antigen changes and the clinical course of the disease; (ii) the relatively limited number of malignant lesions that have been analyzed for nonclassical HLA class I antigen and NK cell-activating ligand expression; and (iii) the conflicting data regarding the role of immunoselection in the generation of malignant cells with HLA antigen and NK cell-activating ligand abnormalities. The technical limitations associated with the assessment of HLA antigen and NK cell-activating ligand expression in malignant lesions as well as the immunological and nonimmunological variables that may confound the impact of HLA antigen and NK cell-activating ligand changes on the clinical course of the disease are also discussed. Future studies aimed at overcoming these limitations and characterizing these variables are expected to provide a solution to the current debate regarding the significance of HLA class I antigen and NK cell-activating ligand abnormalities in malignant lesions.

  18. Circulating antigen tests and urine reagent strips for diagnosis of active schistosomiasis in endemic areas

    NARCIS (Netherlands)

    Ochodo, Eleanor A; Gopalakrishna, Gowri; Spek, Bea; Reitsma, Johannes B; van Lieshout, Lisette; Polman, Katja; Lamberton, Poppy; Bossuyt, Patrick M M; Leeflang, Mariska M G

    2015-01-01

    BACKGROUND: Point-of-care (POC) tests for diagnosing schistosomiasis include tests based on circulating antigen detection and urine reagent strip tests. If they had sufficient diagnostic accuracy they could replace conventional microscopy as they provide a quicker answer and are easier to use.

  19. [Immunochemical properties of conjugated antigens from N-substituted phenothiazines and dibenzazepines with antiarrhythmic activity].

    Science.gov (United States)

    Burkin, A A; Burkin, M A

    2008-01-01

    The use of metabolites of antiarrhythmic drugs (ethmozine, ethacizine, and bonnecor) as haptens in the synthesis of conjugated antigens allowed us to induce the formation of antibodies with different specificity for certain metabolites. A new enzyme immunoassay was developed for the detection of phenothiazine and dibenzazepine derivatives (ethmozine, ethacizine, and bonnecor). Nanogram and subnanogram quantities of these substances may be detected in biological fluids.

  20. CD40 Ligand-activated, antigen-specific B cells are comparable to mature dendritic cells in presenting protein antigens and major histocompatibility complex class I- and class II-binding peptides

    Science.gov (United States)

    Ahmadi, Tahamtan; Flies, Amanda; Efebera, Yvonne; Sherr, David H

    2008-01-01

    Dendritic cells (DC) are increasingly exploited for cell-based immunotherapy. However, limitations in ex vivo DC growth and DC functional heterogeneity have motivated development of complementary antigen-presenting cell sources. Here, the ability of CD40 ligand (CD40L)-activated B cells to fulfil that role was investigated. We demonstrate for the first time that non-specific or antigen-specific murine B cells can be grown for extended periods of time by stimulation with CD40L. These cells rapidly up-regulate and maintain high levels of co-stimulatory molecules. In a head-to-head comparison with DC, CD40L-expanded B cells were comparable to DC in the presentation of peptides to CD4+ and CD8+ T cells. While DC were superior to antigen non-specific CD40L-activated B cells with regard to whole protein (NP-BSA) processing and presentation, CD40L-expanded B cells from NP-BSA-immunized mice were comparable to DC when presenting BSA or NP-BSA to primed primary T cells or when presenting NP linked to an unrelated carrier, CGG, to naïve T cells. Thus, the combination of CD40L activation, which supports B-cell growth and augments intracellular protein processing, and antigen uptake via the B-cell receptor, allows for efficient uptake, processing, and presentation of whole protein antigens in a fashion comparable to that observed with mature DC. Like DC, CD40L-activated B cells efficiently home to secondary lymphoid organs in vivo. This system represents a unique tool for studying primary antigen-specific B cells and the results suggest that the outgrowth of large numbers of highly activated B cells represents a viable and practical complement to DC for cell-based immunotherapy. PMID:18067555

  1. Antitumor activity of sustained N-myc reduction in rhabdomyosarcomas and transcriptional block by antigene therapy.

    Science.gov (United States)

    Tonelli, Roberto; McIntyre, Alan; Camerin, Consuelo; Walters, Zoë S; Di Leo, Korinne; Selfe, Joanna; Purgato, Stefania; Missiaglia, Edoardo; Tortori, Andrea; Renshaw, Jane; Astolfi, Annalisa; Taylor, Kathryn R; Serravalle, Salvatore; Bishop, Ryan; Nanni, Cristina; Valentijn, Linda J; Faccini, Andrea; Leuschner, Ivo; Formica, Serena; Reis-Filho, Jorge S; Ambrosini, Valentina; Thway, Khin; Franzoni, Monica; Summersgill, Brenda; Marchelli, Rosangela; Hrelia, Patrizia; Cantelli-Forti, Giorgio; Fanti, Stefano; Corradini, Roberto; Pession, Andrea; Shipley, Janet

    2012-02-01

    Rhabdomyosarcomas are a major cause of cancer death in children, described with MYCN amplification and, in the alveolar subtype, transcription driven by the PAX3-FOXO1 fusion protein. Our aim was to determine the prevalence of N-Myc protein expression and the potential therapeutic effects of reducing expression in rhabdomyosarcomas, including use of an antigene strategy that inhibits transcription. Protein expression was assessed by immunohistochemistry. MYCN expression was reduced in representative cell lines by RNA interference and an antigene peptide nucleic acid (PNA) oligonucleotide conjugated to a nuclear localization signal peptide. Associated gene expression changes, cell viability, and apoptosis were analyzed in vitro. As a paradigm for antigene therapy, the effects of systemic treatment of mice with rhabdomyosarcoma cell line xenografts were determined. High N-Myc levels were significantly associated with genomic amplification, presence of the PAX3/7-FOXO1 fusion genes, and proliferative capacity. Sustained reduction of N-Myc levels in all rhabdomyosarcoma cell lines that express the protein decreased cell proliferation and increased apoptosis. Positive feedback was shown to regulate PAX3-FOXO1 and N-Myc levels in the alveolar subtype that critically decrease PAX3-FOXO1 levels on reducing N-Myc. Pharmacologic systemic administration of the antigene PNA can eliminate alveolar rhabdomyosarcoma xenografts in mice, without relapse or toxicity. N-Myc, with its restricted expression in non-fetal tissues, is a therapeutic target to treat rhabdomyosarcomas, and blocking gene transcription using antigene oligonucleotide strategies has therapeutic potential in the treatment of cancer and other diseases that has not been previously realized in vivo.

  2. Coevolution of activating and inhibitory receptors within mammalian carcinoembryonic antigen families

    Directory of Open Access Journals (Sweden)

    Kammerer Robert

    2010-02-01

    Full Text Available Abstract Background Most rapidly evolving gene families are involved in immune responses and reproduction, two biological functions which have been assigned to the carcinoembryonic antigen (CEA gene family. To gain insights into evolutionary forces shaping the CEA gene family we have analysed this gene family in 27 mammalian species including monotreme and marsupial lineages. Results Phylogenetic analysis provided convincing evidence that the primordial CEA gene family in mammals consisted of five genes, including the immune inhibitory receptor-encoding CEACAM1 (CEA-related cell adhesion molecule ancestor. Our analysis of the substitution rates within the nucleotide sequence which codes for the ligand binding domain of CEACAM1 indicates that the selection for diversification is, perhaps, a consequence of the exploitation of CEACAM1 by a variety of viral and bacterial pathogens as their cellular receptor. Depending on the extent of the amplification of an ancestral CEACAM1, the number of CEACAM1-related genes varies considerably between mammalian species from less than five in lagomorphs to more than 100 in bats. In most analysed species, ITAM (immunoreceptor tyrosine-based activation motifs or ITAM-like motif-containing proteins exist which contain Ig-V-like, ligand binding domains closely related to that of CEACAM1. Human CEACAM3 is one such protein which can function as a CEACAM1 decoy receptor in granulocytes by mediating the uptake and destruction of specific bacterial pathogens via its ITAM-like motif. The close relationship between CEACAM1 and its ITAM-encoding relatives appears to be maintained by gene conversion and reciprocal recombination. Surprisingly, secreted CEACAMs resembling immunomodulatory CEACAM1-related trophoblast-specific pregnancy-specific glycoproteins (PSGs found in humans and rodents evolved only in a limited set of mammals. The appearance of PSG-like genes correlates with invasive trophoblast growth in these species

  3. The prognostic value of oncogenic antigen 519 (OA-519) expression and proliferative activity detected by antibody MIB-1 in node-negative breast cancer

    DEFF Research Database (Denmark)

    Jensen, V; Ladekarl, M; Holm-Nielsen, P

    1995-01-01

    The prognostic value of oncogenic antigen 519 (OA-519) expression and tumour proliferative activity was evaluated in a retrospective series of 118 patients with low-risk breast cancer. Low risk was defined as negative axillary nodes, tumour diameter

  4. Antigen Display, T-Cell Activation, and Immune Evasion during Acute and Chronic Ehrlichiosis▿

    OpenAIRE

    Nandi, Bisweswar; Chatterjee, Madhumouli; Hogle, Kathryn; McLaughlin, Maura; MacNamara, Katherine; Racine, Rachael; Winslow, Gary M.

    2009-01-01

    How spatial and temporal changes in major histocompatibility complex/peptide antigen presentation to CD4 T cells regulate CD4 T-cell responses during intracellular bacterial infections is relatively unexplored. We have shown that immunization with an ehrlichial outer membrane protein, OMP-19, protects mice against fatal ehrlichial challenge infection, and we identified a CD4 T-cell epitope (IAb/OMP-19107-122) that elicited CD4 T cells following either immunization or infection. Here, we have ...

  5. Plant Virus Particles Carrying Tumour Antigen Activate TLR7 and Induce High Levels of Protective Antibody

    OpenAIRE

    Jantipa Jobsri; Alex Allen; Deepa Rajagopal; Michael Shipton; Kostya Kanyuka; Lomonossoff, George P.; Christian Ottensmeier; Diebold, Sandra S.; Stevenson, Freda K.; Natalia Savelyeva

    2015-01-01

    Induction of potent antibody is the goal of many vaccines targeted against infections or cancer. Modern vaccine designs that use virus-like particles (VLP) have shown efficacy for prophylactic vaccination against virus-associated cancer in the clinic. Here we used plant viral particles (PVP), which are structurally analogous to VLP, coupled to a weak idiotypic (Id) tumour antigen, as a conjugate vaccine to induce antibody against a murine B-cell malignancy. The Id-PVP vaccine incorporates a n...

  6. A GENOME-WIDE EXPLORATION SUGGESTS AN OLIGOGENIC MODEL OF INHERITANCE FOR THE TAFI ACTIVITY AND ITS ANTIGEN LEVELS

    Science.gov (United States)

    Sabater-Lleal, Maria; Buil, Alfonso; Souto, Juan Carlos; Almasy, Laura; Borrell, Montserrat; Lathrop, Mark; Blangero, John; Fontcuberta, Jordi; Soria, José Manuel

    2008-01-01

    Thrombin-Activatable Fibrinolysis Inhibitor (TAFI) is a protein that attenuates fibrinolysis potently. A considerable proportion of its variability levels is genetically determined. It has been associated with arterial and venous thrombosis. We conducted a genomewide linkage scan for genes affecting variation in plasma TAFI levels in 398 subjects from 21 extended Spanish families. The data were analyzed by a variance-component linkage method. A strong linkage was found on the long arm of Chromosome 13, near the DNA marker D13S156, where the structural gene encoding for TAFI is located. In addition, other new linkage signals were detected on chromosome regions 5p and 7q. More importantly, we performed another multipoint linkage analysis of functional TAFI conditioned on TAFI antigen levels. We detected a strong linkage signal on Chromosome 19 (LOD = 3.0, p = 0.0001) suggesting a novel QTL in this region involved in the specific functional activity of TAFI, regardless of the TAFI antigen levels. One notable aspect of this study is the identification of new QTLs that reveal a clearer picture of the genetic determinants responsible for variation in TAFI levels. Another is the replication of the linkage signal of the CPB2 gene, which confirms an important genetic determinant for TAFI antigen levels. These results strongly suggest an oligogenic mode of inheritance for TAFI, in which CPB2 gene accounts for a proportion of the variation of the phenotype together with other unknown genes that may represent potential risk factors for thrombotic disease. PMID:18563448

  7. Antigen induced production of υ-interferon ex vivo, in the peripheral blood of patients with active pulmonary tuberculosis

    Directory of Open Access Journals (Sweden)

    Z. M. Zagdyn

    2013-01-01

    Full Text Available Tuberculosis (TB is one of the most significant problems in the Russian Health Care. Russia remains on the list of the 22 countries with a high TB incidence and on the third place in the world with a high prevalence of Drug Resistant TB [1]. It is urgently needed to develop new TB diagnostic methods as well as effective measures of the specific TB prevention, including a development of the novel vaccines, so we have to know better about the most immunogenic antigens of Mycobacterium Tuberculosis. We studied the Interferon-Q production in the whole blood after stimulating immune response with different proteins of Mycobacterium Tuberculosis in patients with active TB. The study results permitted us to evaluate the immunogenicity of the previously known proteins (Ag85a и ESAT-6 in comparison to the recently identified ones (Rv2957, Rv2958c и Rv0447, analyzing simultaneously their relation to tuberculin, as well as to antigens of the different viruses (Human Immunodeficiency Virus, Cytomegalovirus, Epstein-Barr Virus, Influenza Virus. Protein Rv2958c, unlike protein ESAT-6, showed the high immunogenicity in comparison to tuberculin. The expressed immunogenicity of protein Rv2958c might be indicated a possible greatest specificity of immune response to this antigen in TB patients. Meanwhile, bacillary tuberculosis was strongly associated with low immune response to this protein. Also we were found statistical differences in immune responses of patients to the different Mycobacterium Tuberculosis antigens depending on the drug sensitivity. In addition it was interesting to know about a significantly low immune response of patients with Drug Resistant TB to protein pp65 CMV.

  8. Tumor Antigen-Dependent and Tumor Antigen-Independent Activation of Antitumor Activity in T Cells by a Bispecific Antibody-Modified Tumor Vaccine

    Directory of Open Access Journals (Sweden)

    Philippe Fournier

    2010-01-01

    Full Text Available New approaches of therapeutic cancer vaccination are needed to improve the antitumor activity of T cells from cancer patients. We studied over the last years the activation of human T cells for tumor attack. To this end, we combined the personalized therapeutic tumor vaccine ATV-NDV—which is obtained by isolation, short in vitro culture, irradiation, and infection of patient's tumor cells by Newcastle Disease Virus (NDV—with bispecific antibodies (bsAbs binding to this vaccine and introducing anti-CD3 (signal 1 and anti-CD28 (signal 2 antibody activities. This vaccine called ATV-NDV/bsAb showed the unique ability to reactivate a preexisting potentially anergized antitumor memory T cell repertoire. But it also activated naive T cells to have antitumor properties in vitro and in vivo. This innovative concept of direct activation of cancer patients' T cells via cognate and noncognate interactions provides potential for inducing strong antitumor activities aiming at overriding T cell anergy and tumor immune escape mechanisms.

  9. Improved Activation toward Primary Colorectal Cancer Cells by Antigen-Specific Targeting Autologous Cytokine-Induced Killer Cells

    Directory of Open Access Journals (Sweden)

    Claudia Schlimper

    2012-01-01

    Full Text Available Adoptive therapy of malignant diseases with cytokine-induced killer (CIK cells showed promise in a number of trials; the activation of CIK cells from cancer patients towards their autologous cancer cells still needs to be improved. Here, we generated CIK cells ex vivo from blood lymphocytes of colorectal cancer patients and engineered those cells with a chimeric antigen receptor (CAR with an antibody-defined specificity for carcinoembryonic antigen (CEA. CIK cells thereby gained a new specificity as defined by the CAR and showed increase in activation towards CEA+ colon carcinoma cells, but less in presence of CEA− cells, indicated by increased secretion of proinflammatory cytokines. Redirected CIK activation was superior by CAR-mediated CD28-CD3ζ than CD3ζ signaling only. CAR-engineered CIK cells from colon carcinoma patients showed improved activation against their autologous, primary carcinoma cells from biopsies resulting in more efficient tumour cell lysis. We assume that adoptive therapy with CAR-modified CIK cells shows improved selectivity in targeting autologous tumour lesions.

  10. Flow cytometry-based methods for assessing soluble scFv activities and detecting pathogen antigens in solution

    Energy Technology Data Exchange (ETDEWEB)

    Gray, Sean; Weigel, Kris M.; Miller, Keith D.; Ndung' u, Joseph; Buscher, Philippe; Tran, Thao N.; Baird, Cheryl L.; Cangelosi, Gerard A.

    2010-04-01

    Novel methods are reported for evaluating and utilizing single chain fragment variable (scFv) antibodies derived from yeast-display libraries. Yeast-display was used to select scFv specific to invariant surface glycoproteins (ISG) of Trypanosoma brucei. A limiting step in the isolation of scFv from nonimmune libraries is the conversion of highly active yeast-displayed scFv into soluble antibodies that can be used in standard immunoassays. Challenges include limited solubility or activity following secretion and purification of scFv. For this reason, few scFv derived from yeast-display platforms have moved into development and implementation as diagnostic reagents. To address this problem, assays were developed that employ both yeastdisplayed and secreted scFv as analytical reagents. The first is a competitive inhibition flow cytometry (CIFC) assay that detects secreted scFv by virtue of its ability to competitively inhibit the binding of biotinylated antigen to yeast-displayed scFv. The second is an epitope binning assay that uses secreted scFv toidentify additional yeast-displayed scFv that bind nonoverlapping or noncompeting epitopes on an antigen. The epitope binning assay was used not only to identify sandwich assay pairs with yeast-displayed scFv, but also to identify active soluble scFv present in low concentration in a crude expression extract. Finally, a CIFC assay was developed that bypasses entirely the need for soluble scFv expression, by using yeast displayed scFv to detect unlabeled antigen in samples. These methods will facilitate the continued development and practical implementation of scFv derived from yeast-display libraries.

  11. Loss of proliferation and antigen presentation activity following internalization of polydispersed carbon nanotubes by primary lung epithelial cells.

    Directory of Open Access Journals (Sweden)

    Mandavi Kumari

    Full Text Available Interactions between poly-dispersed acid functionalized single walled carbon nanotubes (AF-SWCNTs and primary lung epithelial (PLE cells were studied. Peritoneal macrophages (PMs, known phagocytic cells were used as positive controls in this study. Recovery of live cells from cultures of PLE cells and PMs was significantly reduced in the presence of AF-SWCNTs, in a time and dose dependent manner. Both PLE cells as well as PMs could take up fluorescence tagged AF-SWCNTs in a time dependent manner and this uptake was significantly blocked by cytochalasin D, an agent that blocks the activity of acto-myosin fibers and therefore the phagocytic activity of cells. Confocal microscopic studies confirmed that AF-SWCNTs were internalized by both PLE cells and PMs. Intra-trachially instilled AF-SWCNTs could also be taken up by lung epithelial cells as well as alveolar macrophages. Freshly isolated PLE cells had significant cell division activity and cell cycling studies indicated that treatment with AF-SWCNTs resulted in a marked reduction in S-phase of the cell cycle. In a previously standardized system to study BCG antigen presentation by PLE cells and PMs to sensitized T helper cells, AF-SWCNTs could significantly lower the antigen presentation ability of both cell types. These results show that mouse primary lung epithelial cells can efficiently internalize AF-SWCNTs and the uptake of nanotubes interfered with biological functions of PLE cells including their ability to present BCG antigens to sensitized T helper cells.

  12. Increased CD8+ T cell response to Epstein-Barr virus lytic antigens in the active phase of multiple sclerosis.

    Directory of Open Access Journals (Sweden)

    Daniela F Angelini

    Full Text Available It has long been known that multiple sclerosis (MS is associated with an increased Epstein-Barr virus (EBV seroprevalence and high immune reactivity to EBV and that infectious mononucleosis increases MS risk. This evidence led to postulate that EBV infection plays a role in MS etiopathogenesis, although the mechanisms are debated. This study was designed to assess the prevalence and magnitude of CD8+ T-cell responses to EBV latent (EBNA-3A, LMP-2A and lytic (BZLF-1, BMLF-1 antigens in relapsing-remitting MS patients (n = 113 and healthy donors (HD (n = 43 and to investigate whether the EBV-specific CD8+ T cell response correlates with disease activity, as defined by clinical evaluation and gadolinium-enhanced magnetic resonance imaging. Using HLA class I pentamers, lytic antigen-specific CD8+ T cell responses were detected in fewer untreated inactive MS patients than in active MS patients and HD while the frequency of CD8+ T cells specific for EBV lytic and latent antigens was higher in active and inactive MS patients, respectively. In contrast, the CD8+ T cell response to cytomegalovirus did not differ between HD and MS patients, irrespective of the disease phase. Marked differences in the prevalence of EBV-specific CD8+ T cell responses were observed in patients treated with interferon-β and natalizumab, two licensed drugs for relapsing-remitting MS. Longitudinal studies revealed expansion of CD8+ T cells specific for EBV lytic antigens during active disease in untreated MS patients but not in relapse-free, natalizumab-treated patients. Analysis of post-mortem MS brain samples showed expression of the EBV lytic protein BZLF-1 and interactions between cytotoxic CD8+ T cells and EBV lytically infected plasma cells in inflammatory white matter lesions and meninges. We therefore propose that inability to control EBV infection during inactive MS could set the stage for intracerebral viral reactivation and disease relapse.

  13. Non-major histocompatibility complex-restricted cytotoxic activity of blood mononuclear cells stimulated with secreted mycobacterial proteins and other mycobacterial antigens

    DEFF Research Database (Denmark)

    Ravn, P; Pedersen, B K

    1994-01-01

    Several observations indicate that non-major histocompatibility complex (MHC)-restricted cytotoxicity, mediated for example by natural killer cells and lymphokine-activated killer cells, may serve as an important antimicrobial defense mechanism. The purpose of the present study was to investigate......+ cells proliferated and expressed interleukin-2 receptors following stimulation with mycobacterial antigens. Depletion studies after antigen stimulation showed that the cytotoxic effector cells were CD16+ CD56+ and CD4-; the CD4+ cells alone did not mediate non-MHC-restricted cytotoxicity. To evaluate...... activity was reduced. This reduction was abolished by interleukin-2 but not by gamma interferon. We conclude that several mycobacterial antigens are able to induce non-MHC-restricted cytotoxicity. This study indicates that non-MHC-restricted cytotoxicity following stimulation with mycobacterial antigens...

  14. Anti-allergic activity of R-phycocyanin from Porphyra haitanensis in antigen-sensitized mice and mast cells.

    Science.gov (United States)

    Liu, Qingmei; Wang, Youzhao; Cao, Minjie; Pan, Tzuming; Yang, Yang; Mao, Haiyan; Sun, Lechang; Liu, Guangming

    2015-04-01

    The prevalence of food allergy has increased in Asian countries. Marine algae have been proposed as the potential resource for anti-allergic therapeutics. The present study was aimed at isolating R-phycocyanin (RPC) from Porphyra haitanensis and determining the anti-allergy potential of RPC in antigen-sensitized mice and mast cells. In animal experiments, RPC could effectively reduce tropomyosin (TM)-specific immunoglobulin E (IgE) and histamine levels, alleviate allergy symptoms and jejunum tissue inflammation in mice, and inhibit the expression and release of cytokines (interleukin-4 (IL-4) and IL-13) in peritoneal lavage fluid. In spleen lymphocyte experiments, high purity of RPC skewed the immunological function of CD4(+) T cells towards Th1 activity. A higher expression of interferon (IFN)-γ was induced by a synergistic effect of TM and RPC. Through the Jun N-terminal kinase and Janus kinase 2 signaling pathways, IFN-γ synthesis was induced by RPC in combination with TM. Anti-allergic effect of RPC was evaluated in IgE-mediated rat mast RBL-2H3 cells. The results demonstrated that RPC inhibited allergy markers, including the release of β-hexosaminidase, histamine and ROS in antigen-sensitized RBL-2H3 cells. RPC also suppressed the production of pro-inflammatory factors (IL-4 and tumor necrosis factor-α). In conclusion, RPC decreased allergic sensitization against TM by blocking Th2 cell polarization as well as suppressed the release of allergic-mediators in antigen-stimulated mast cells. It may be used as a functional food component or active pharmaceutical ingredient for allergic patients. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Cellular ras gene activity is required for full neoplastic transformation by the large tumor antigen of SV40.

    Science.gov (United States)

    Raptis, L; Brownell, H L; Corbley, M J; Wood, K W; Wang, D; Haliotis, T

    1997-08-01

    To investigate the role of the cellular ras gene product in neoplastic transformation by the SV40 large tumor antigen (SVLT), murine C3H10T1/2 cells were rendered deficient in Ras activity by transfection with inducible or constitutive antisense ras gene constructs or through the introduction of the dominant-negative mutant, ras(asn17). Consistent with previous results, SVLT-induced morphological transformation was unaffected by the down-regulation of c-ras gene product activity. On the other hand, colony formation in soft agar and tumorigenicity in nude mice were drastically reduced in c-Ras-deficient cells. In addition, SVLT expression in C3H10T1/2 cells led to increased c-Ras activity, as determined by an increase in the Ras-bound GTP/GTP + GDP ratio. These results suggest that c-Ras is required for full neoplastic transformation by SVLT.

  16. Expression of costimulatory molecules in antigen-activated peritoneal macrophages treated with either ovalbumin or palmitoyl-ova conjugates

    Directory of Open Access Journals (Sweden)

    Flávia Márcia Oliveira

    2013-12-01

    Full Text Available One of the mechanisms by which adjuvants are believed to promote T-cell activation and prevent induction of oral tolerance is by up-regulating the expression of co-stimulatory molecules on antigen presenting cells. Mice treated orally with palmitoyl-ovalbumin conjugates become immunized, while those treated with native ovalbumin (Ova become tolerant. Cells from the peritoneal cavity of B6D2F1 mice were cultured in the presence of 0.01, or 0.1 mg/100ml of either Ova, or palmitoyl-Ova and tested for the presence of cell markers. PE-conjugated anti-mouse CD80, CD86, and CD11b antibodies as well as biotin-PE were used to stain the antigen-activated peritoneal cells. A significant increase in the expression of CD86 and CD80 was observed following in vitro stimulation with palmitoyl-Ova; additionally, both Ova and palmitoyl-Ova induced the basal expression of CD11b. These findings could be related with the strong T-cell proliferative response induced by palmitoyl-Ova.

  17. Methimazole therapy in Graves' disease influences the abnormal expression of CD69 (early activation antigen) on T cells.

    Science.gov (United States)

    Corrales, J J; López, A; Ciudad, J; Mories, M T; Miralles, J M; Orfao, A

    1997-12-01

    At present, the in vivo response of T, B and natural killer (NK) cells to antithyroid drug therapy remains largely unknown. In the present study, we have prospectively analyzed the in vivo effects of methimazole treatment on a large number of circulating T and NK cell subsets, some of them expressing cell surface activation antigens involved in the very early phase of the immune response, in a group of 17 hyperthyroid, untreated patients with Graves' disease (GD). As one of the first events during T cell activation is the expression of interleukin (IL) receptors, we also studied the binding of IL-2 and IL-6 to T cells. Patients with Graves' disease were sequentially studied at diagnosis/before treatment (day 0) and 7, 14, 30, 90 and 180 days after methimazole therapy. The results were compared with both a group of 19 age- and sex-matched control volunteers and a group of 20 untreated/euthyroid patients with Graves' disease in long-term remission. The combination of flow cytometry and three-color immunofluorescence revealed a clear (P effect of the drug. Expression of the low-affinity receptor for IL-2 (CD25)--another early T cell activation marker--was not altered in Graves' disease, but the binding of IL-2 and IL-6 to T cells exhibited a progressive and parallel increase during the first 30 days of therapy, decreasing thereafter. Our results show that methimazole therapy downregulates the abnormally high expression of the CD69 early activation antigen on T cells, being less effective on inducing changes in other T cell activation markers and in NK cells.

  18. Regulation of IgG memory responses by helper and suppressor T cells activated by the type 2 antigen, polyvinylpyrrolidone

    Science.gov (United States)

    1985-01-01

    T cells from CAF1 mice immunized with various amounts of the type 2 antigen polyvinylpyrrolidone (PVP) were assessed for their ability to provide help to PVP-specific memory B cells for the production of IgG. Low doses (0.0025 micrograms) of PVP consistently activated helper T cells (Th), which were required for the production of IgG by primed B cells. In contrast, T cells from mice primed with higher amounts (0.25 or 25 micrograms) of PVP did not provide significant help to the same B cells for IgG production. Moreover, when mixed with B cells and low- dose PVP-primed Th, T cells from mice primed with 0.25 or 25 micrograms PVP suppressed PVP-specific IgG, but not IgM antibody responses. The suppressor cells induced by higher amounts of PVP were eliminated either by injecting cyclophosphamide (CY) before priming with PVP, or by treating the primed T cells with anti-Lyt-2.2 and C before transfer. Pretreatment of suppressor T cell (Ts) donors with CY or removal of Lyt- 2+ T cells not only eliminated Ts activity, but also unmasked significant Th activity in the T cells from high-dose PVP-primed mice. Thus, both low and high amounts of PVP can activate Th, although high amounts of PVP also induce Ts, the activity of which predominates in a normal unfractionated T cell population. The amount of PVP (0.0025 micrograms) that induces dominant help for IgG memory responses was only marginally immunogenic for induction of primary PVP-specific IgM responses, while 0.25 and 25 micrograms PVP, which induce dominant suppression for IgG memory responses, are optimally immunogenic for primary IgM responses. These results are discussed in the context of the inability of most type 2 antigens to elicit primary IgG responses or to prime memory B cells for production of IgG, responses which are dependent on the function of antigen-specific Th. PMID:3159816

  19. Towards improved diagnosis of von Willebrand disease: comparative evaluations of several automated von Willebrand factor antigen and activity assays.

    Science.gov (United States)

    Favaloro, Emmanuel J; Mohammed, Soma

    2014-12-01

    von Willebrand disease (VWD) is reportedly the most common bleeding disorder and arises from deficiency and/or defects of von Willebrand factor (VWF). Laboratory diagnosis and typing has important management implications and requires a wide range of tests, including VWF activity and antigen, and involves differential identification of qualitative vs quantitative defects. We have assessed several VWF antigen and activity assays (collagen binding [VWF:CB], ristocetin cofactor [VWF:RCo] and the new Siemens INNOVANCE assay [VWF:Ac], employing latex particles and gain of function recombinant glycoprotein Ib to facilitate VWF binding and agglutination without need for ristocetin) using different instrumentation, including the new Sysmex CS-5100, with a large sample test set (n=600). We included retrospective plus prospective study designs, and also evaluated desmopressin responsiveness plus differential sensitivity to high molecular weight VWF. VWF:Ag and VWF:RCo results from different methods were respectively largely comparable, although some notable differences were evident, including one high false normal VWF:Ag value (105 U/dL) on a type 3 VWD sample, possibly due to heterophile antibody interference in the latex-based CS-5100 methodology. VWF:Ac was largely comparable to VWF:RCo, but VWF:CB showed discrepant findings to both VWF:RCo and VWF:Ac with some patients, most notably patients with type 2M VWD. (a) VWF:Ag on different platforms are largely interchangeable, as are VWF:RCo on different platforms, except for occasional (some potentially important) differences, and manufacturer recommended methods may otherwise require some assay optimization; (b) VWF:RCo and VWF:Ac are largely interchangeable, except for occasional differences that may also relate to assay design (differing optimizations); (c) VWF:CB provides an additional activity to supplement VWF:RCo or VWF:Ac activity assays, and is not interchangeable with either. Crown Copyright © 2014. Published by

  20. 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

  1. Activation of Type II Cells into Regenerative Stem Cell Antigen-1+ Cells during Alveolar Repair

    Science.gov (United States)

    Kumar, Varsha Suresh; Zhang, Wei; Rehman, Jalees; Malik, Asrar B.

    2015-01-01

    The alveolar epithelium is composed of two cell types: type I cells comprise 95% of the gas exchange surface area, whereas type II cells secrete surfactant, while retaining the ability to convert into type I cells to induce alveolar repair. Using lineage-tracing analyses in the mouse model of Pseudomonas aeruginosa–induced lung injury, we identified a population of stem cell antigen (Sca)-1–expressing type II cells with progenitor cell properties that mediate alveolar repair. These cells were shown to be distinct from previously reported Sca-1–expressing bronchioalveolar stem cells. Microarray and Wnt reporter studies showed that surfactant protein (Sp)-C+Sca-1+ cells expressed Wnt signaling pathway genes, and inhibiting Wnt/β-catenin signaling prevented the regenerative function of Sp-C+Sca-1+ cells in vitro. Thus, P. aeruginosa–mediated lung injury induces the generation of a Sca-1+ subset of type II cells. The progenitor phenotype of the Sp-C+Sca-1+ cells that mediates alveolar epithelial repair might involve Wnt signaling. PMID:25474582

  2. Humoral markers of active Epstein-Barr virus infection associate with anti-extractable nuclear antigen autoantibodies and plasma galectin-3 binding protein in systemic lupus erythematosus.

    Science.gov (United States)

    Rasmussen, N S; Nielsen, C T; Houen, G; Jacobsen, S

    2016-12-01

    We investigated if signs of active Epstein-Barr virus and cytomegalovirus infections associate with certain autoantibodies and a marker of type I interferon activity in patients with systemic lupus erythematosus. IgM and IgG plasma levels against Epstein-Barr virus early antigen diffuse and cytomegalovirus pp52 were applied as humoral markers of ongoing/recently active Epstein-Barr virus and cytomegalovirus infections, respectively. Plasma galectin-3 binding protein served as a surrogate marker of type I interferon activity. The measurements were conducted in 57 systemic lupus erythematosus patients and 29 healthy controls using ELISAs. Regression analyses and univariate comparisons were performed for associative evaluation between virus serology, plasma galectin-3 binding protein and autoantibodies, along with other clinical and demographic parameters. Plasma galectin-3 binding protein concentrations were significantly higher in systemic lupus erythematosus patients (P = 0.009) and associated positively with Epstein-Barr virus early antigen diffuse-directed antibodies and the presence of autoantibodies against extractable nuclear antigens in adjusted linear regressions (B = 2.02 and 2.02, P = 0.02 and P = 0.002, respectively). Furthermore, systemic lupus erythematosus patients with anti-extractable nuclear antigens had significantly higher antibody levels against Epstein-Barr virus early antigen diffuse (P = 0.02). Our study supports a link between active Epstein-Barr virus infections, positivity for anti-extractable nuclear antigens and increased plasma galectin-3 binding protein concentrations/type I interferon activity in systemic lupus erythematosus patients. © The Author(s) 2016.

  3. 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

    2017-11-11

    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.

  4. Treponema pallidum (syphilis) antigen TpF1 induces angiogenesis through the activation of the IL-8 pathway.

    Science.gov (United States)

    Pozzobon, Tommaso; Facchinello, Nicola; Bossi, Fleur; Capitani, Nagaja; Benagiano, Marisa; Di Benedetto, Giulietta; Zennaro, Cristina; West, Nicole; Codolo, Gaia; Bernardini, Marialina; Baldari, Cosima Tatiana; D'Elios, Mario Milco; Pellegrini, Luca; Argenton, Francesco; de Bernard, Marina

    2016-01-05

    Over 10 million people every year become infected by Treponema pallidum and develop syphilis, a disease with broad symptomatology that, due to the difficulty to eradicate the pathogen from the highly vascularized secondary sites of infection, is still treated with injections of penicillin. Unlike most other bacterial pathogens, T. pallidum infection produces indeed a strong angiogenic response whose mechanism of activation, however, remains unknown. Here, we report that one of the major antigen of T. pallidum, the TpF1 protein, has growth factor-like activity on primary cultures of human endothelial cells and activates specific T cells able to promote tissue factor production. The growth factor-like activity is mediated by the secretion of IL-8 but not of VEGF, two known angiogenic factors. The pathogen's factor signals IL-8 secretion through the activation of the CREB/NF-κB signalling pathway. These findings are recapitulated in an animal model, zebrafish, where we observed that TpF1 injection stimulates angiogenesis and IL-8, but not VEGF, secretion. This study suggests that the angiogenic response observed during secondary syphilis is triggered by TpF1 and that pharmacological therapies directed to inhibit IL-8 response in patients should be explored to treat this disease.

  5. [Transformation activity and antigenicity of the human papillomavirus type 58 E6E7 fusion gene mutant].

    Science.gov (United States)

    Wang, He; Yu, Ji-yun; Li, Li

    2013-07-01

    To develop a prophylactic and therapeutic vaccine against human papillomavirus (HPV) type 58-associated cervical carcinoma, and explore its transformation activity and antigenicity. The E6 and E7 three amino acid codons in the HPV 58 virus were modified respectively and fused. The modified and fused gene was named HPV58 mE6E7. The recombinant HPV58 mE6E7 gene was inserted into pIRES-neo vector to generate plasmid pIRES-neo-HPV58 mE6E7. Then NIH/3T3 cell line was transfected with plasmid pIRES-neo-HPV58 mE6E7. The pIRES-neo-HPV58 mE6E7-transfected cells were the experimental group, pIRES-neo-HPV58 E6E7-transfected cells were the positive control group, and pIRES-neo empty vector-transfected cells were the negative control group. The expression of HPV58 mE6E7 protein in the experimental cells was detected by flow cytometry, immunofluorescence and Western blot. The transformation activity of HPV58 mE6E7 was tested by soft agar colony formation assay and subcutaneously tumors in nude mice. Finally, DNA vaccine was constructed with HPV58 mE6E7 fusion antigen and used to immunize C57BL/6 mice with the vaccine plasmids. The specific serum antibodies were detected by EIISA, and the number of splenic specific CD8(+) T cells secreting IFN-γ of the immunized mice was detected by ELISPOT assay. Sequencing confirmed the expected mutation and a 100% homogeneity of the HPV58 E6E7 fusion gene. Stable transfected NIH/3T3 cells expressing HPV58 mE6E7 and HPV58 E6E7 gene were 70.3% and 84.1%, respectively. The relative expressions of HPV58 mE6E7 and HPV58 E6E7 fusion protein in 3T3-HPV58 mE6E7 experimental cells and 3T3-HPV58 E6E7 positive control cells were 2.1 ± 1.7 and 3.8 ± 1.4, respectively, and were negative in the negative control group. No colony formation was found in the experimental and 3T3-neo negative control cell groups, and 31 colonies were found in the positive control cell group, among them 10 colonies were consisted of more than 50 cells. No tumor mass was formed

  6. The immunostimulating activities of anti-tumor polysaccharide from K1 capsular (polysaccharide) antigen isolated from Klebsiella pneumoniae.

    Science.gov (United States)

    Ho, C Y; Lo, T W; Leung, K N; Fung, K P; Choy, Y M

    2000-01-01

    We have previously shown that K1 capsular polysaccharide antigen (K1CPS) of Klebsiella exhibits anti-tumor activities. In the present study, we examined the effect of K1CPS on cytotoxic effector cells. We found that K1CPS could activate many cytotoxic effector cells including alloreactive cytotoxic T cells and tumor-infiltrating lymphocytes (TILs). Moreover, K1CPS could increase the anti-tumor activity of lymphokine-activated killer (LAK) cells, both in vitro and in vivo. The i.p. injection of K1CPS in low dose could enhance the LAK cytotoxicity and the effect was further potentiated by coculture of LAK cells with K1CPS and low concentration of murine rIL-2 in vitro. The phenotypic characterization revealed that K1CPS might contribute to the increase in CD3+ LAK cell subpopulation by its in vivo priming effect. In addition, the K1CPS-treated LAK cells were able to inhibit the growth of WEHI-164 tumor cells in vivo in Winn-type inhibition assay. Subcutaneous (s.c.) and intraperitoneal (i.p.) adoptive infusion of LAK cells (splenocytes from K1CPS-treated WEHI-164-bearing mice cultured with K1CPS-plus-rIL-2) into WEHI-164 sarcoma-bearing mice could slightly cause regression in terms of tumor diameter, and more significantly in sarcoma weight.

  7. Stimulation of 3'-->5' exonuclease and 3'-phosphodiesterase activities of yeast apn2 by proliferating cell nuclear antigen.

    Science.gov (United States)

    Unk, Ildiko; Haracska, Lajos; Gomes, Xavier V; Burgers, Peter M J; Prakash, Louise; Prakash, Satya

    2002-09-01

    The Apn2 protein of Saccharomyces cerevisiae contains 3'-->5' exonuclease and 3'-phosphodiesterase activities, and these activities function in the repair of DNA strand breaks that have 3'-damaged termini and which are formed in DNA by the action of oxygen-free radicals. Apn2 also has an AP endonuclease activity and functions in the removal of abasic sites from DNA. Here, we provide evidence for the physical and functional interaction of Apn2 with proliferating cell nuclear antigen (PCNA). As indicated by gel filtration and two-hybrid studies, Apn2 interacts with PCNA both in vitro and in vivo and mutations in the consensus PCNA-binding motif of Apn2 abolish this interaction. Importantly, PCNA stimulates the 3'-->5' exonuclease and 3'-phosphodiesterase activities of Apn2. We have examined the involvement of the interdomain connector loop (IDCL) and of the carboxy-terminal domain of PCNA in Apn2 binding and found that Apn2 binds PCNA via distinct domains dependent upon whether the binding is in the absence or presence of DNA. In the absence of DNA, Apn2 binds PCNA through its IDCL domain, whereas in the presence of DNA, when PCNA has been loaded onto the template-primer junction by replication factor C, the C-terminal domain of PCNA mediates the binding.

  8. Functional Analysis of the Glucuronyltransferases GlcAT-P and GlcAT-S of Drosophila melanogaster: Distinct Activities towards the O-linked T-antigen

    Directory of Open Access Journals (Sweden)

    Isabelle Breloy

    2016-01-01

    Full Text Available The Drosophila melanogaster glucuronyltransferases dGlcAT-S and dGlcAT-P were reported to be expressed ubiquitously and results of in vitro activity assays indicate a functional redundancy. We analyzed both transferases in vivo and in vitro and could show significant differences in their activity towards N-and O-glycoproteins in vivo. While GlcAT-P is able to use N-linked N-acetyllactosamine chains and the O-linked T-antigen as a substrate to form non-sulfated HNK1- (GlcAβ1-3Galβ1-4GlcNAcβ1- and glucuronyl-T-antigens in vivo, GlcAT-S adds glucuronic acid only to N-linked chains, thereby synthesizing only the non-sulfated HNK1-antigen.

  9. Exosomes derived from M. Bovis BCG infected macrophages activate antigen-specific CD4+ and CD8+ T cells in vitro and in vivo.

    Directory of Open Access Journals (Sweden)

    Pramod K Giri

    2008-06-01

    Full Text Available Activation of both CD4(+ and CD8(+ T cells is required for an effective immune response to an M. tuberculosis infection. However, infected macrophages are poor antigen presenting cells and may be spatially separated from recruited T cells, thus limiting antigen presentation within a granuloma. Our previous studies showed that infected macrophages release from cells small membrane-bound vesicles called exosomes which contain mycobacterial lipid components and showed that these exosomes could stimulate a pro-inflammatory response in naïve macrophages. In the present study we demonstrate that exosomes stimulate both CD4(+ and CD8(+ splenic T cells isolated from mycobacteria-sensitized mice. Although the exosomes contain MHC I and II as well as costimulatory molecules, maximum stimulation of T cells required prior incubation of exosomes with antigen presenting cells. Exosomes isolated from M. bovis and M. tuberculosis infected macrophages also stimulated activation and maturation of mouse bone marrow-derived dendritic cells. Interestingly, intranasal administration of mice with exosomes isolated from M. bovis BCG infected macrophages induce the generation of memory CD4(+ and CD8(+ T cells. The isolated T cells also produced IFN-gamma upon restimulation with BCG antigens. The release of exosomes from infected macrophages may overcome some of the defects in antigen presentation associated with mycobacterial infections and we suggest that exosomes may be a promising M. tuberculosis vaccine candidate.

  10. Artificial neural network for prediction of antigenic activity for a major conformational epitope in the hepatitis C virus NS3 protein.

    Science.gov (United States)

    Lara, James; Wohlhueter, Robert M; Dimitrova, Zoya; Khudyakov, Yury E

    2008-09-01

    Insufficient knowledge of general principles for accurate quantitative inference of biological properties from sequences is a major obstacle in the rationale design of proteins with predetermined activities. Due to this deficiency, protein engineering frequently relies on the use of computational approaches focused on the identification of quantitative structure-activity relationship (SAR) for each specific task. In the current article, a computational model was developed to define SAR for a major conformational antigenic epitope of the hepatitis C virus (HCV) non-structural protein 3 (NS3) in order to facilitate a rationale design of HCV antigens with improved diagnostically relevant properties. We present an artificial neural network (ANN) model that connects changes in the antigenic properties and structure of HCV NS3 recombinant proteins representing all 6 HCV genotypes. The ANN performed quantitative predictions of the enzyme immunoassay (EIA) Signal/Cutoff (S/Co) profiles from sequence information alone with 89.8% accuracy. Amino acid positions and physicochemical factors strongly associated with the HCV NS3 antigenic properties were identified. The positions most significantly contributing to the model were mapped on the NS3 3D structure. The location of these positions validates the major associations found by the ANN model between antigenicity and structure of the HCV NS3 proteins. Matlab code is available at the following URL address: http://bio-ai.myeweb.net/box_widget.html

  11. Activation of Cdc42 is necessary for sustained oscillations of Ca2+ and PIP2 stimulated by antigen in RBL mast cells

    Directory of Open Access Journals (Sweden)

    Marcus M. Wilkes

    2014-07-01

    Full Text Available Antigen stimulation of mast cells via FcεRI, the high-affinity receptor for IgE, triggers a signaling cascade that requires Ca2+ mobilization for exocytosis of secretory granules during the allergic response. To characterize the role of Rho GTPases in FcεRI signaling, we utilized a mutant RBL cell line, B6A4C1, that is deficient in antigen-stimulated Cdc42 activation important for these processes. Recently the importance of stimulated intracellular oscillations has emerged, and we find that B6A4C1 cells exhibit severely attenuated Ca2+ oscillations in response to antigen, which are restored to wild-type RBL-2H3 levels by expression of constitutively active Cdc42 G12V or by a GEF for Cdc42, DOCK7, but not when the C-terminal di-arginine motif of active Cdc42 is mutated to di-glutamine. We found that antigen-stimulated FcεRI endocytosis, which occurs independently of Ca2+ mobilization, is also defective in B6A4C1 cells, and Cdc42 G12V reconstitutes this response as well. Thus, activation of Cdc42 occurs prior to and is critical for antigen-stimulated pathways leading separately to both Ca2+ mobilization and receptor endocytosis. Accounting for these downstream functional consequences, we show that Cdc42 G12V reconstitutes antigen-stimulated oscillations of phosphatidylinositol 4,5-bisphosphate (PIP2 at the plasma membrane in mutant B6A4C1 cells, pointing to Cdc42 participation in the regulation of stimulated PIP2 synthesis.

  12. High levels of tissue plasminogen activator (tPA antigen precede the development of type 2 diabetes in a longitudinal population study. The Northern Sweden MONICA Study

    Directory of Open Access Journals (Sweden)

    Jansson Jan-Håkan

    2003-12-01

    Full Text Available Abstract Background Impaired fibrinolysis is found in impaired glucose tolerance and type 2 diabetes, associated with components of the metabolic syndrome. There are no data concerning fibrinolysis in subjects with normal glucose tolerance that convert to diabetes. Methods We studied the activities of tissue plasminogen activator (tPA and plasminogen activator inhibitor-1 (PAI-1 and the levels of tPA antigen (a marker of endothelial dysfunction in 551 subjects with normal glucose tolerance in 1990 in relation to incident diabetes during nine years of follow-up. Results Subjects with diabetes at follow-up (n = 15 had significantly lower baseline tPA activity and higher PAI-1 activity and tPA antigen than non-converters. The risk of diabetes increased linearly across quartiles of PAI-activity (p = 0.007 and tPA antigen (p p = 0.026. The risk of diabetes with low tPA activity or high PAI-1 activity persisted after adjustment for age and sex but diminished to a non-significant level after further adjustments. The odds ratio of diabetes for high tPA antigen was 10.4 (95% confidence interval 2.7–40 adjusted for age and sex. After further adjustment for diastolic blood pressure, waist circumference, insulin, triglycerides, fasting and post load glucose the odds ratio was 6.5 (1.3–33, p = 0.024. Conclusions Impaired fibrinolysis and endothelial dysfunction are evident in subjects with normal glucose tolerance who later develop diabetes. High tPA antigen is predictive of future diabetes independent from the metabolic syndrome.

  13. Transgenic Expression of IL15 Improves Antiglioma Activity of IL13Rα2-CAR T Cells but Results in Antigen Loss Variants.

    Science.gov (United States)

    Krenciute, Giedre; Prinzing, Brooke L; Yi, Zhongzhen; Wu, Meng-Fen; Liu, Hao; Dotti, Gianpietro; Balyasnikova, Irina V; Gottschalk, Stephen

    2017-07-01

    Glioblastoma (GBM) is the most aggressive primary brain tumor in adults and is virtually incurable with conventional therapies. Immunotherapy with T cells expressing GBM-specific chimeric antigen receptors (CAR) is an attractive approach to improve outcomes. Although CAR T cells targeting GBM antigens, such as IL13 receptor subunit α2 (IL13Rα2), HER2, and EGFR variant III (EGFRvIII), have had antitumor activity in preclinical models, early-phase clinical testing has demonstrated limited antiglioma activity. Transgenic expression of IL15 is an appealing strategy to enhance CAR T-cell effector function. We tested this approach in our IL13Rα2-positive glioma model in which limited IL13Rα2-CAR T-cell persistence results in recurrence of antigen-positive gliomas. T cells were genetically modified with retroviral vectors encoding IL13Rα2-CARs or IL15 (IL13Rα2-CAR.IL15 T cells). IL13Rα2-CAR.IL15 T cells recognized glioma cells in an antigen-dependent fashion, had greater proliferative capacity, and produced more cytokines after repeated stimulations in comparison with IL13Rα2-CAR T cells. No autonomous IL13Rα2-CAR.IL15 T-cell proliferation was observed; however, IL15 expression increased IL13Rα2-CAR T-cell viability in the absence of exogenous cytokines or antigen. In vivo, IL13Rα2-CAR.IL15 T cells persisted longer and had greater antiglioma activity than IL13Rα2-CAR T cells, resulting in a survival advantage. Gliomas recurring after 40 days after T-cell injection had downregulated IL13Rα2 expression, indicating that antigen loss variants occur in the setting of improved T-cell persistence. Thus, CAR T cells for GBM should not only be genetically modified to improve their proliferation and persistence, but also to target multiple antigens.Summary: Glioblastoma responds imperfectly to immunotherapy. Transgenic expression of IL15 in T cells expressing CARs improved their proliferative capacity, persistence, and cytokine production. The emergence of antigen loss

  14. Hepatocyte growth factor is a potent trigger of neutrophil adhesion through rapid activation of lymphocyte function-associated antigen-1.

    Science.gov (United States)

    Mine, S; Tanaka, Y; Suematu, M; Aso, M; Fujisaki, T; Yamada, S; Eto, S

    1998-11-01

    Recruitment of neutrophils into tissue occurs in several pathologic processes such as inflammation, atherosclerosis, thrombosis, and ischemia. In inflammation, the adherence of neutrophils to the endothelium depends on neutrophil integrins. Integrin-mediated adhesion is tightly regulated, ie, integrins do not function if neutrophils are not triggered by certain activation stimuli. We investigated the role of hepatocyte growth factor (HGF) in the adhesion of neutrophils to endothelial cells in inflammation. Our results showed that (a) HGF induced not only lymphocyte function-associated antigen-1 (LFA-1)-mediated adhesion of neutrophils to endothelial cells but also transmigration of neutrophils in a concentration-dependent manner; (b) HGF functionally transformed neutrophil integrin LFA-1 to active form and reduced surface L-selectin expression level; (c) HGF induced F-actin polymerization and cytoskeletal rearrangement within seconds; (d) genistein, a tyrosine kinase inhibitor, as well as wortmannin, a phosphoinositide 3 (PI 3)-kinase inhibitor, inhibited both F-actin polymerization and LFA-1-mediated adhesion of neutrophils to endothelial cells; and (e) neutrophils in cutaneous inflamed tissue highly expressed HGF and serum levels of HGF were elevated in patients with Behçet's disease, which is associated with neutrophilic vasculitis and marked neutrophil accumulation. Our results indicate that HGF plays a pivotal role in integrin-mediated adhesion and transmigration of neutrophils to sites of acute inflammation through cytoskeletal rearrangement activated by tyrosine kinase and PI 3-kinase signaling.

  15. Antigen-Specific Monoclonal Antibodies Isolated from B Cells Expressing Constitutively Active STAT5

    NARCIS (Netherlands)

    Scheeren, F.A.; van Geelen, C.M.M.; Yasuda, E.; Spits, H.; Beaumont, T.

    2011-01-01

    Background: Fully human monoclonal antibodies directed against specific pathogens have a high therapeutic potential, but are difficult to generate. Methodology/Principal Findings: Memory B cells were immortalized by expressing an inducible active mutant of the transcription factor Signal Transducer

  16. A Diet, Physical Activity, and Meditation Intervention in Men With Rising Prostate-Specific Antigen (PSA)

    National Research Council Canada - National Science Library

    Hebert, James R

    2006-01-01

    ... 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...

  17. 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...

  18. A Diet, Physical Activity, and Meditation Intervention in Men With Rising Prostate-Specific Antigen (PSA)

    National Research Council Canada - National Science Library

    Hebert, James R

    2007-01-01

    ... 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...

  19. Humoral markers of active Epstein-Barr virus infection associate with anti-extractable nuclear antigen autoantibodies and plasma galectin-3 binding protein in systemic lupus erythematosus

    DEFF Research Database (Denmark)

    Rasmussen, N S; Nielsen, C T; Houen, G

    2016-01-01

    We investigated if signs of active Epstein-Barr virus and cytomegalovirus infections associate with certain autoantibodies and a marker of type I interferon activity in patients with systemic lupus erythematosus. IgM and IgG plasma levels against Epstein-Barr virus early antigen diffuse and cytom......We investigated if signs of active Epstein-Barr virus and cytomegalovirus infections associate with certain autoantibodies and a marker of type I interferon activity in patients with systemic lupus erythematosus. IgM and IgG plasma levels against Epstein-Barr virus early antigen diffuse...... and cytomegalovirus pp52 were applied as humoral markers of ongoing/recently active Epstein-Barr virus and cytomegalovirus infections, respectively. Plasma galectin-3 binding protein served as a surrogate marker of type I interferon activity. The measurements were conducted in 57 systemic lupus erythematosus patients...

  20. Active immunization with an octa-valent Staphylococcus aureus antigen mixture in models of S. aureus bacteremia and skin infection in mice.

    Directory of Open Access Journals (Sweden)

    Sanne van den Berg

    Full Text Available Proteomic studies with different Staphylococcus aureus isolates have shown that the cell surface-exposed and secreted proteins IsaA, LytM, Nuc, the propeptide of Atl (pro-Atl and four phenol-soluble modulins α (PSMα are invariantly produced by this pathogen. Therefore the present study was aimed at investigating whether these proteins can be used for active immunization against S. aureus infection in mouse models of bacteremia and skin infection. To this end, recombinant His-tagged fusions of IsaA, LytM, Nuc and pro-Atl were isolated from Lactococcus lactis or Escherichia coli, while the PSMα1-4 peptides were chemically synthesized. Importantly, patients colonized by S. aureus showed significant immunoglobulin G (IgG responses against all eight antigens. BALB/cBYJ mice were immunized subcutaneously with a mixture of the antigens at day one (5 μg each, and boosted twice (25 μg of each antigen with 28 days interval. This resulted in high IgG responses against all antigens although the response against pro-Atl was around one log lower compared to the other antigens. Compared to placebo-immunized mice, immunization with the octa-valent antigen mixture did not reduce the S. aureus isolate P load in blood, lungs, spleen, liver, and kidneys in a bacteremia model in which the animals were challenged for 14 days with a primary load of 3 × 10(5 CFU. Discomfort scores and animal survival rates over 14 days did not differ between immunized mice and placebo-immunized mice upon bacteremia with S. aureus USA300 (6 × 10(5 CFU. In addition, this immunization did not reduce the S. aureus isolate P load in mice with skin infection. These results show that the target antigens are immunogenic in both humans and mice, but in the used animal models do not result in protection against S. aureus infection.

  1. A simple method for measuring immune complex-mediated, Fc gamma receptor dependent antigen-specific activation of primary human T cells.

    Science.gov (United States)

    Junker, Fabian; Krishnarajah, Sinduya; Qureshi, Omar; Humphreys, David; Fallah-Arani, Farnaz

    2018-03-01

    Immune complex (IC) deposition of IgG containing autologous antigens has been observed in autoimmunity. This can lead to IC-mediated antigen uptake and presentation by antigen presenting cells (APC) driving T cell dependent inflammation. IgG receptors (FcγRs) have been suggested to be involved in this process. Since ICs have been linked to autoimmune diseases, interfering with IC mediated effects on APCs and subsequent autoimmune T cell activation via FcγR blockade may be therapeutically beneficial. However, this is currently challenging due to a lack of translatable animal models and specific human in vitro assays to study IC-driven T cell responses. Here, we developed a simple cellular assay to study IC-mediated T cell activation in vitro using human peripheral blood mononuclear cells and tetanus toxoid as a model antigen. We observed that tetanus ICs led to a strong induction of T cell proliferation and release of pro-inflammatory cytokines, which are hallmarks of chronic inflammation. This process was exacerbated when compared to tetanus toxoid challenge alone. IC-mediated T cell effects were FcγR dependent and inhibited by high-dose intravenous IgG (IVIg), a drug often used for the clinical treatments of autoimmune diseases. Similar effects were also seen using a hepatitis antigen. Consequently, we propose our assay as a rapid yet robust alternative to more labour-intense and time-consuming protocols, for example involving separate maturation of dendritic cells followed by T cell co-culture to study antigen specific primary T cell activation. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. 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.

  3. Prospective evaluation of a whole-blood test using Mycobacterium tuberculosis-specific antigens ESAT-6 and CFP-10 for diagnosis of active tuberculosis

    DEFF Research Database (Denmark)

    Ravn, Pernille; Munk, Martin E; Andersen, Ase B

    2005-01-01

    A new immunodiagnostic test based on the Mycobacterium tuberculosis-specific antigens CFP-10/ESAT-6(QFT-RD1) has been launched as an aid in the diagnosis of latent tuberculosis (TB) infection (LTBI). The aim of this study was to evaluate this test for the diagnosis of active TB. Eighty-two patients...

  4. Response of fibrinolytic activity and factor VIII-related antigen to stimulation with desmopressin in hyperlipoproteinemia

    NARCIS (Netherlands)

    Brommer, E.J.P.; Leuven, J.A.G.; Barrett-Bergshoeff, M.M.; Schouten, J.A.

    1982-01-01

    Impairment of fibrinolysis is supposed to contribute to CVD. In 38 hyperlipoproteinemic patients, known to be at risk for early CVD, fibrinolytic activity was measured before and after stimulation with DDAVP. A negative correlation was found between serum triglyceride levels and fibrinolytic

  5. Chemical tools for the study of proteolytic activities associated with antigen presentation

    NARCIS (Netherlands)

    Swieten, Paul Franciscus van

    2007-01-01

    The synthesis of different tools to study protease activities are presented. Irreversible inhibitors of the proteasome or cathepsins were equipped with reporter groups and other functionalities to generate probes to study these proteases under different conditions. A two step labeling strategy

  6. Immortalized myeloid suppressor cells trigger apoptosis in antigen-activated T lymphocytes.

    Science.gov (United States)

    Apolloni, E; Bronte, V; Mazzoni, A; Serafini, P; Cabrelle, A; Segal, D M; Young, H A; Zanovello, P

    2000-12-15

    We described a generalized suppression of CTL anamnestic responses that occurred in mice bearing large tumor nodules or immunized with powerful recombinant viral immunogens. Immune suppression entirely depended on GM-CSF-driven accumulation of CD11b(+)/Gr-1(+) myeloid suppressor cells (MSC) in secondary lymphoid organs. To further investigate the nature and properties of MSC, we immortalized CD11b(+)/Gr-1(+) cells isolated from the spleens of immunosuppressed mice, using a retrovirus encoding the v-myc and v-raf oncogenes. Immortalized cells expressed monocyte/macrophage markers (CD11b, F4/80, CD86, CD11c), but they differed from previously characterized macrophage lines in their capacities to inhibit T lymphocyte activation. Two MSC lines, MSC-1 and MSC-2, were selected based upon their abilities to inhibit Ag-specific proliferative and functional CTL responses. MSC-1 line was constitutively inhibitory, while suppressive functions of MSC-2 line were stimulated by exposure to the cytokine IL-4. Both MSC lines triggered the apoptotic cascade in Ag-activated T lymphocytes by a mechanism requiring cell-cell contact. Some well-known membrane molecules involved in the activation of apoptotic pathways (e.g., TNF-related apoptosis-inducing ligand, Fas ligand, TNF-alpha) were ruled out as candidate effectors for the suppression mechanism. The immortalized myeloid lines represent a novel, useful tool to shed light on the molecules involved in the differentiation of myeloid-related suppressors as well as in the inhibitory pathway they use to control T lymphocyte activation.

  7. A viral vectored prime-boost immunization regime targeting the malaria Pfs25 antigen induces transmission-blocking activity.

    Directory of Open Access Journals (Sweden)

    Anna L Goodman

    Full Text Available The ookinete surface protein Pfs25 is a macrogamete-to-ookinete/ookinete stage antigen of Plasmodium falciparum, capable of exerting high-level anti-malarial transmission-blocking activity following immunization with recombinant protein-in-adjuvant formulations. Here, this antigen was expressed in recombinant chimpanzee adenovirus 63 (ChAd63, human adenovirus serotype 5 (AdHu5 and modified vaccinia virus Ankara (MVA viral vectored vaccines. Two immunizations were administered to mice in a heterologous prime-boost regime. Immunization of mice with AdHu5 Pfs25 at week 0 and MVA Pfs25 at week 10 (Ad-MVA Pfs25 resulted in high anti-Pfs25 IgG titers, consisting of predominantly isotypes IgG1 and IgG2a. A single priming immunization with ChAd63 Pfs25 was as effective as AdHu5 Pfs25 with respect to ELISA titers at 8 weeks post-immunization. Sera from Ad-MVA Pfs25 immunized mice inhibited the transmission of P. falciparum to the mosquito both ex vivo and in vivo. In a standard membrane-feeding assay using NF54 strain P. falciparum, oocyst intensity in Anopheles stephensi mosquitoes was significantly reduced in an IgG concentration-dependent manner when compared to control feeds (96% reduction of intensity, 78% reduction in prevalence at a 1 in 5 dilution of sera. In addition, an in vivo transmission-blocking effect was also demonstrated by direct feeding of immunized mice infected with Pfs25DR3, a chimeric P. berghei line expressing Pfs25 in place of endogenous Pbs25. In this assay the density of Pfs25DR3 oocysts was significantly reduced when mosquitoes were fed on vaccinated as compared to control mice (67% reduction of intensity, 28% reduction in prevalence and specific IgG titer correlated with efficacy. These data confirm the utility of the adenovirus-MVA vaccine platform for the induction of antibodies with transmission-blocking activity, and support the continued development of this alternative approach to transmission-blocking malaria subunit

  8. Extrahelical (CAG)/(CTG) triplet repeat elements support proliferating cell nuclear antigen loading and MutLα endonuclease activation.

    Science.gov (United States)

    Pluciennik, Anna; Burdett, Vickers; Baitinger, Celia; Iyer, Ravi R; Shi, Kevin; Modrich, Paul

    2013-07-23

    MutLα endonuclease can be activated on covalently continuous DNA that contains a MutSα- or MutSβ-recognizable lesion and a helix perturbation that supports proliferating cell nuclear antigen (PCNA) loading by replication factor C, providing a potential mechanism for triggering mismatch repair on nonreplicating DNA. Because mouse models for somatic expansion of disease-associated (CAG)n/(CTG)n triplet repeat sequences have implicated both MutSβ and MutLα and have suggested that expansions can occur in the absence of replication, we have asked whether an extrahelical (CAG)n or (CTG)n element is sufficient to trigger MutLα activation. (CAG)n and (CTG)n extrusions in relaxed closed circular DNA do in fact support MutSβ-, replication factor C-, and PCNA-dependent activation of MutLα endonuclease, which can incise either DNA strand. Extrahelical elements of two or three repeat units are the preferred substrates for MutLα activation, and extrusions of this size also serve as moderately effective sites for loading the PCNA clamp. Relaxed heteroduplex DNA containing a two or three-repeat unit extrusion also triggers MutSβ- and MutLα-endonuclease-dependent mismatch repair in nuclear extracts of human cells. This reaction occurs without obvious strand bias at about 10% the rate of that observed with otherwise identical nicked heteroduplex DNA. These findings provide a mechanism for initiation of triplet repeat processing in nonreplicating DNA that is consistent with several features of the model of Gomes-Pereira et al. [Gomes-Pereira M, Fortune MT, Ingram L, McAbney JP, Monckton DG (2004) Hum Mol Genet 13(16):1815-1825]. They may also have implications for triplet repeat processing at a replication fork.

  9. Inhibition of large T antigen ATPase activity as a potential strategy to develop anti-polyomavirus JC drugs.

    Science.gov (United States)

    Randhawa, Parmjeet; Zeng, G; Bueno, M; Salgarkar, A; Lesniak, Andrew; Isse, K; Seyb, K; Perry, A; Charles, I; Hustus, C; Huang, M; Smith, M; Glicksman, Marcie A

    2014-12-01

    This study evaluates polyomavirus JC (JCV) large T antigen (LTA) as a potential target for drug development. LTA is a hexameric protein with a helicase activity that is powered by ATP binding and hydrolysis. The helicase and ATPase function is critical for viral replication. Recombinant JCV LTA was produced in an Escherichia coli based expression plasmid. ATPase activity was measured using the malachite green assay. A high throughput screen was completed using a brain-biased library of 75,000 drug-like compounds selected for physicochemical properties consistent with blood-brain barrier permeability. Five compounds showed non-competitive inhibition of ATPase activity with an EC50 ⩽ 15 μM. Modest antiviral activity was demonstrated in an immunofluorescence assay for JCV VP-1 expression in COS7 cells (EC50 15, 18, 20, 27, and 52 μM respectively). The compounds also inhibited viral replication in a real time PCR assay at comparable concentrations. LD50 in the MTS96 and Cell TiterGlo assays was >100 μM for all compounds in COS7 as well as HEK293 cells. However, two compounds inhibited cell proliferation in culture with IC50 values of 43 and 34 μM respectively. Despite substantial amino acid similarity between polyomavirus JC, BK and SV40 proteins, these compounds differ from those previously reported to inhibit SV40 LTA ATPase in chemical structure as well as a non-competitive mechanism of inhibition. LTA ATPase is a valid target for discovery. Additional screening and chemical optimization is needed to develop clinically useful compounds with less toxicity, which should be measured by metabolic as well as cell proliferation assays. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Extrahelical (CAG)/(CTG) triplet repeat elements support proliferating cell nuclear antigen loading and MutLα endonuclease activation

    Science.gov (United States)

    Pluciennik, Anna; Burdett, Vickers; Baitinger, Celia; Iyer, Ravi R.; Shi, Kevin; Modrich, Paul

    2013-01-01

    MutLα endonuclease can be activated on covalently continuous DNA that contains a MutSα- or MutSβ-recognizable lesion and a helix perturbation that supports proliferating cell nuclear antigen (PCNA) loading by replication factor C, providing a potential mechanism for triggering mismatch repair on nonreplicating DNA. Because mouse models for somatic expansion of disease-associated (CAG)n/(CTG)n triplet repeat sequences have implicated both MutSβ and MutLα and have suggested that expansions can occur in the absence of replication, we have asked whether an extrahelical (CAG)n or (CTG)n element is sufficient to trigger MutLα activation. (CAG)n and (CTG)n extrusions in relaxed closed circular DNA do in fact support MutSβ-, replication factor C-, and PCNA-dependent activation of MutLα endonuclease, which can incise either DNA strand. Extrahelical elements of two or three repeat units are the preferred substrates for MutLα activation, and extrusions of this size also serve as moderately effective sites for loading the PCNA clamp. Relaxed heteroduplex DNA containing a two or three-repeat unit extrusion also triggers MutSβ- and MutLα-endonuclease-dependent mismatch repair in nuclear extracts of human cells. This reaction occurs without obvious strand bias at about 10% the rate of that observed with otherwise identical nicked heteroduplex DNA. These findings provide a mechanism for initiation of triplet repeat processing in nonreplicating DNA that is consistent with several features of the model of Gomes-Pereira et al. [Gomes-Pereira M, Fortune MT, Ingram L, McAbney JP, Monckton DG (2004) Hum Mol Genet 13(16):1815–1825]. They may also have implications for triplet repeat processing at a replication fork. PMID:23840062

  11. Soluble human leukocyte antigen-g5 activates extracellular signal-regulated protein kinase signaling and stimulates trophoblast invasion.

    Directory of Open Access Journals (Sweden)

    YiFan Guo

    Full Text Available Soluble human leukocyte antigen-G (HLA-G is a non-classical class Ib HLA molecule that is secreted from blastocysts. Soluble HLA-G modulates the immune tolerance of the mother and can be used as a prognostic factor for the clinical pregnancy rate. However, the underlying mechanism of how soluble HLA-G5 affects pregnancy remains largely unknown. We hypothesized that soluble HLA-G5 promotes successful implantation and pregnancy by modulating trophoblast invasion through receptor binding and activation of extracellular signal-regulated protein kinase (ERK signaling pathway. Recombinant HLA-G5 protein over-expressed in E. coli BL21 was purified to near homogeneity. We studied the expression of HLA-G5 and its receptors, the leukocyte immunoglobulin-like receptor subfamily B1 (LILRB1 and killer cell immunoglobulin-like receptor 2DL4 (KIR2DL4, in primary trophoblasts and trophoblastic (JAr and JEG-3 cell lines by florescence-labeled HLA-G5. HLA-G5 was detected in the primary trophoblasts and JEG-3 cells. The LILRB1 and KIR2DL4 receptors were expressed in both primary trophoblasts and trophoblastic cell lines. HLA-G5 stimulated cell invasion (p<0.05 and increased urokinase (uPA and matrix metalloproteinases (MMPs transcripts and their activity (p<0.05 in trophoblastic cells. HLA-G5 activated the ERK signaling pathway and induced ERK1/2 phosphorylation in the trophoblastic cell lines. Addition of ERK inhibitors (U0126 and PD98059 nullified the stimulatory effect of HLA-G5 on trophoblastic cell invasion. Taken together, HLA-G5 induced trophoblast invasion by binding to KIR2DL4 and LILRB1, by increasing uPA and MMPs expressions and by activating the ERK signaling pathway.

  12. Antibodies to Meningococcal H.8 (Lip) Antigen Fail to Show Bactericidal Activity

    Science.gov (United States)

    1990-01-01

    des IgA et des IgM. Des liquides d’ascite (2-1-CA2) de souris riches en anticorps monoclonaux anti-Lip contenaient 28 400 unites d’anticorps en ELISA... monoclonaux n’avaient pas non plus d’activit6 bactericide contre ces souches. La faible activitt bactdricide associee aux anticorps monoclonaux et...active au trdsyl et utilise en chromatographie d’affinit6 pour purifier des anticorps anti-Lip A partir de sdrums de convalescents et de lapins

  13. The Shc family protein adaptor, Rai, negatively regulates T cell antigen receptor signaling by inhibiting ZAP-70 recruitment and activation.

    Directory of Open Access Journals (Sweden)

    Micol Ferro

    Full Text Available Rai/ShcC is a member of the Shc family of protein adaptors expressed with the highest abundance in the central nervous system, where it exerts a protective function by coupling neurotrophic receptors to the PI3K/Akt survival pathway. Rai is also expressed, albeit at lower levels, in other cell types, including T and B lymphocytes. We have previously reported that in these cells Rai attenuates antigen receptor signaling, thereby impairing not only cell proliferation but also, opposite to neurons, cell survival. Here we have addressed the mechanism underlying the inhibitory activity of Rai on TCR signaling. We show that Rai interferes with the TCR signaling cascade one of the earliest steps--recruitment of the initiating kinase ZAP-70 to the phosphorylated subunit of the TCR/CD3 complex, which results in a generalized dampening of the downstream signaling events. The inhibitory activity of Rai is associated to its inducible recruitment to phosphorylated CD3, which occurs in the physiological signaling context of the immune synapse. Rai is moreover found as a pre-assembled complex with ZAP-70 and also constitutively interacts with the regulatory p85 subunit of PI3K, similar to neuronal cells, notwithstanding the opposite biological outcome, i.e. impairment of PI-3K/Akt activation. The data highlight the ability of Rai to establish interactions with the TCR and key signaling mediators which, either directly (e.g. by inhibiting ZAP-70 recruitment to the TCR or sequestering ZAP-70/PI3K in the cytosol or indirectly (e.g. by promoting the recruitment of effectors responsible for signal extinction prevent full triggering of the TCR signaling cascade.

  14. Soluble human leukocyte antigen-g5 activates extracellular signal-regulated protein kinase signaling and stimulates trophoblast invasion.

    Science.gov (United States)

    Guo, YiFan; Lee, Cheuk-Lun; So, Kam-Hei; Gao, Jing; Yeung, William S B; Yao, YuanQing; Lee, Kai-Fai

    2013-01-01

    Soluble human leukocyte antigen-G (HLA-G) is a non-classical class Ib HLA molecule that is secreted from blastocysts. Soluble HLA-G modulates the immune tolerance of the mother and can be used as a prognostic factor for the clinical pregnancy rate. However, the underlying mechanism of how soluble HLA-G5 affects pregnancy remains largely unknown. We hypothesized that soluble HLA-G5 promotes successful implantation and pregnancy by modulating trophoblast invasion through receptor binding and activation of extracellular signal-regulated protein kinase (ERK) signaling pathway. Recombinant HLA-G5 protein over-expressed in E. coli BL21 was purified to near homogeneity. We studied the expression of HLA-G5 and its receptors, the leukocyte immunoglobulin-like receptor subfamily B1 (LILRB1) and killer cell immunoglobulin-like receptor 2DL4 (KIR2DL4), in primary trophoblasts and trophoblastic (JAr and JEG-3) cell lines by florescence-labeled HLA-G5. HLA-G5 was detected in the primary trophoblasts and JEG-3 cells. The LILRB1 and KIR2DL4 receptors were expressed in both primary trophoblasts and trophoblastic cell lines. HLA-G5 stimulated cell invasion (ptrophoblastic cells. HLA-G5 activated the ERK signaling pathway and induced ERK1/2 phosphorylation in the trophoblastic cell lines. Addition of ERK inhibitors (U0126 and PD98059) nullified the stimulatory effect of HLA-G5 on trophoblastic cell invasion. Taken together, HLA-G5 induced trophoblast invasion by binding to KIR2DL4 and LILRB1, by increasing uPA and MMPs expressions and by activating the ERK signaling pathway.

  15. Loss of the waaL O-antigen ligase prevents surface activation of the flagellar gene cascade in Proteus mirabilis.

    Science.gov (United States)

    Morgenstein, Randy M; Clemmer, Katy M; Rather, Philip N

    2010-06-01

    Proteus mirabilis is a Gram-negative bacterium that undergoes a physical and biochemical change from a vegetative swimmer cell (a typical Gram-negative rod) to an elongated swarmer cell when grown on a solid surface. In this study, we report that a transposon insertion in the waaL gene, encoding O-antigen ligase, blocked swarming motility on solid surfaces but had little effect on swimming motility in soft agar. The waaL mutant was unable to differentiate into a swarmer cell. Differentiation was also prevented by a mutation in wzz, encoding a chain length determinant for O antigen, but not by a mutation in wzyE, encoding an enzyme that polymerizes enterobacterial common antigen, a surface polysaccharide different from the lipid A::core. In wild-type P. mirabilis, increased expression of the flhDC operon occurs after growth on solid surfaces and is required for the high-level expression of flagellin that is characteristic of swarmer cells. However, in both the waaL and the wzz mutants, the flhDC operon was not activated during growth on agar. A loss-of-function mutation in the rcsB response regulator or overexpression of flhDC restored swarming to the waaL mutant, despite the absence of O antigen. Therefore, although O antigen may serve a role in swarming by promoting wettability, the loss of O antigen blocks a regulatory pathway that links surface contact with the upregulation of flhDC expression.

  16. Single-step antigen loading and activation of dendritic cells by mRNA electroporation for the purpose of therapeutic vaccination in melanoma patients.

    Science.gov (United States)

    Bonehill, Aude; Van Nuffel, An M T; Corthals, Jurgen; Tuyaerts, Sandra; Heirman, Carlo; François, Violaine; Colau, Didier; van der Bruggen, Pierre; Neyns, Bart; Thielemans, Kris

    2009-05-15

    A critical factor determining the effectiveness of currently used dendritic cell (DC)-based vaccines is the DC activation or maturation status. We have recently shown that the T-cell stimulatory capacity of DCs pulsed with tumor-antigen-derived peptides can be considerably increased by activating the DCs through electroporation with mRNA encoding CD40 ligand, CD70, and a constitutively active Toll-like receptor 4 (TriMix DCs). Here, we investigate whether TriMix DCs can be coelectroporated with whole tumor-antigen-encoding mRNA. The T-cell stimulatory capacity of TriMix DCs pulsed with the immunodominant MelanA-A2 peptide and that of TriMix DCs coelectroporated with MelanA mRNA were compared in vitro. TriMix DCs were also coelectroporated with mRNA encoding Mage-A3, Mage-C2, tyrosinase, or gp100. The capacity of these DCs to stimulate tumor-antigen-specific T cells in melanoma patients was investigated both in vitro before vaccination and after DC vaccination. Like peptide-pulsed TriMix DCs, TriMix DCs coelectroporated with MelanA mRNA are very potent in inducing MelanA-specific CD8(+) T cells in vitro. These T cells have an activated phenotype, show cytolytic capacity, and produce inflammatory cytokines in response to specific stimulation. TriMix DCs coelectroporated with tyrosinase are able to stimulate tyrosinase-specific CD8(+) T cells in vitro from the blood of nonvaccinated melanoma patients. Furthermore, TriMix DCs coelectroporated with Mage-A3, Mage-C2, or tyrosinase are able to induce antigen-specific CD8(+) T cells through therapeutic DC vaccination. TriMix DCs coelectroporated with whole tumor-antigen mRNA stimulate antigen-specific T cells in vitro and induce antigen-specific T-cell responses in melanoma patients through vaccination. Therefore, they represent a promising new approach for antitumor immunotherapy.

  17. Major Histocompatibility Complex Class I Molecules Modulate Activation Threshold and Early Signaling of T Cell Antigen Receptor–γ/δ Stimulated by Nonpeptidic Ligands

    Science.gov (United States)

    Carena, Ilaria; Shamshiev, Abdijapar; Donda, Alena; Colonna, Marco; Libero, Gennaro De

    1997-01-01

    Killer cell inhibitory receptors and CD94-NKG2-A/B heterodimers are major histocompatibility complex class I–specific inhibitory receptors expressed by natural killer cells, T cell antigen receptor (TCR)-γ/δ cells, and a subset of TCR-α/β cells. We studied the functional interaction between TCR-γ/δ and CD94, this inhibitory receptor being expressed on the majority of γ/δ T cells. When engaged by human histocompatibility leukocyte antigen class I molecules, CD94 downmodulates activation of human TCR-γ/δ by phosphorylated ligands. CD94-mediated inhibition is more effective at low than at high doses of TCR ligand, which may focus T cell responses towards antigen-presenting cells presenting high amounts of antigen. CD94 engagement has major effects on TCR signaling cascade. It facilitates recruitment of SHP-1 phosphatase to TCR–CD3 complex and affects phosphorylation of Lck and ZAP-70 kinase, but not of CD3 ζ chain upon TCR triggering. These events may cause abortion of proximal TCR-mediated signaling and set a higher TCR activation threshold. PMID:9362537

  18. The actin cytoskeleton modulates the activation of iNKT cells by segregating CD1d nanoclusters on antigen-presenting cells

    Science.gov (United States)

    Torreno-Pina, Juan A.; Manzo, Carlo; Salio, Mariolina; Aichinger, Michael C.; Oddone, Anna; Lakadamyali, Melike; Shepherd, Dawn; Besra, Gurdyal S.; Cerundolo, Vincenzo

    2016-01-01

    Invariant natural killer T (iNKT) cells recognize endogenous and exogenous lipid antigens presented in the context of CD1d molecules. The ability of iNKT cells to recognize endogenous antigens represents a distinct immune recognition strategy, which underscores the constitutive memory phenotype of iNKT cells and their activation during inflammatory conditions. However, the mechanisms regulating such “tonic” activation of iNKT cells remain unclear. Here, we show that the spatiotemporal distribution of CD1d molecules on the surface of antigen-presenting cells (APCs) modulates activation of iNKT cells. By using superresolution microscopy, we show that CD1d molecules form nanoclusters at the cell surface of APCs, and their size and density are constrained by the actin cytoskeleton. Dual-color single-particle tracking revealed that diffusing CD1d nanoclusters are actively arrested by the actin cytoskeleton, preventing their further coalescence. Formation of larger nanoclusters occurs in the absence of interactions between CD1d cytosolic tail and the actin cytoskeleton and correlates with enhanced iNKT cell activation. Importantly and consistently with iNKT cell activation during inflammatory conditions, exposure of APCs to the Toll-like receptor 7/8 agonist R848 increases nanocluster density and iNKT cell activation. Overall, these results define a previously unidentified mechanism that modulates iNKT cell autoreactivity based on the tight control by the APC cytoskeleton of the sizes and densities of endogenous antigen-loaded CD1d nanoclusters. PMID:26798067

  19. Erythrocyte Binding Activity Displayed by a Selective Group of Plasmodium vivax Tryptophan Rich Antigens Is Inhibited by Patients’ Antibodies

    Science.gov (United States)

    Tyagi, Rupesh Kumar; Sharma, Yagya Dutta

    2012-01-01

    Plasmodium vivax is a very common but non-cultivable malaria parasite affecting large human population in tropical world. To develop therapeutic reagents for this malaria, the parasite molecules involved in host-parasite interaction need to be investigated as they form effective vaccine or drug targets. We have investigated here the erythrocyte binding activity of a group of 15 different Plasmodium vivax tryptophan rich antigens (PvTRAgs). Only six of them, named PvTRAg, PvTRAg38, PvTRAg33.5, PvTRAg35.2 PvTRAg69.4 and PvATRAg74, showed binding to host erythrocytes. That the PvTRAgs binding to host erythrocytes was specific was evident from the competitive inhibition and saturation kinetics results. The erythrocyte receptors for these six PvTRAgs were resistant to trypsin and neuraminidase. These receptors were also chymotrypsin resistant except the receptors for PvTRAg38 and PvATRAg74 which were partially sensitive to this enzyme. The cross-competition studies showed that the chymotrypsin resistant RBC receptor for each of these two proteins was different. Altogether, there seems to be three RBC receptors for these six PvTRAgs and each PvTRAg has two RBC receptors. Both RBC receptors for PvTRAg, PvTRAg69.4, PvTRAg33.5, and PvTRAg35.2 were common to all these four proteins. These four PvTRAgs also shared one of their RBC receptors with PvTRAg38 as well as with PvATRAg74. The erythrocyte binding activity of these six PvTRAgs was inhibited by the respective rabbit polyclonal antibodies as well as by the natural antibodies produced by the P. vivax exposed individuals. It is concluded that only selective few PvTRAgs show erythrocyte binding activity involving different receptor molecules which can be blocked by the natural antibodies. Further studies on these receptor and ligands may lead to the development of therapeutic reagents for P. vivax malaria. PMID:23236392

  20. An exhaustion-like phenotype constrains the activity of CD4+ T cells specific for a self and melanoma antigen.

    Directory of Open Access Journals (Sweden)

    Matthew P Rausch

    Full Text Available While the immune system has the capacity to recognize and destroy melanoma, tolerance mechanisms often hinder the development of effective anti-tumor immune responses. Since many melanoma antigens are self proteins expressed in normal melanocytes, self antigen exposure before tumor development can negatively impact the function of T cells specific for these self/tumor antigens. However, the contribution of self tolerance to anti-melanoma T cell dysfunction remains largely unexplored. We have previously described a TCR transgenic (Tg mouse model in which T cells specific for the self/melanoma antigen, tyrosinase-related protein 1 (TRP1, develop in the presence of endogenous TRP1 expression (Ag+ and diminished antigen presentation due to the absence of gamma-interferon-inducible lysosomal thiol reductase (GILT-/-. We show that TRP1-specific T cells from these Ag+GILT-/-Tg mice do not protect from melanoma tumor growth, fail to induce autoimmune vitiligo, and undergo diminished proliferation compared to T cells from Ag-GILT+/+Tg mice. Despite an increased frequency of TRP1-specific Treg cells in Ag+GILT-/-Tg mice compared to Ag-GILT+/+Tg animals, Treg cell depletion only partially rescues the proliferative capacity of T cells from TRP1-expressing mice, suggesting the involvement of additional suppressive mechanisms. An increased percentage of melanoma-specific T cells from Ag+GILT-/-Tg animals express PD-1, an inhibitory receptor associated with the maintenance of T cell exhaustion. Antibody blockade of PD-1 partially improves the ability of TRP1-specific T cells from Ag+GILT-/-Tg mice to produce IL-2. These findings demonstrate that melanoma-specific T cells exposed to a self/melanoma antigen in healthy tissue develop an exhaustion-like phenotype characterized by PD-1-mediated immunosuppression prior to encounter with tumor.

  1. Stimulation of 3′→5′ Exonuclease and 3′-Phosphodiesterase Activities of Yeast Apn2 by Proliferating Cell Nuclear Antigen

    OpenAIRE

    Unk, Ildiko; Haracska, Lajos; Gomes, Xavier V.; Burgers, Peter M. J.; Prakash, Louise; Prakash, Satya

    2002-01-01

    The Apn2 protein of Saccharomyces cerevisiae contains 3′→5′ exonuclease and 3′-phosphodiesterase activities, and these activities function in the repair of DNA strand breaks that have 3′-damaged termini and which are formed in DNA by the action of oxygen-free radicals. Apn2 also has an AP endonuclease activity and functions in the removal of abasic sites from DNA. Here, we provide evidence for the physical and functional interaction of Apn2 with proliferating cell nuclear antigen (PCNA). As i...

  2. 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.

  3. Exploring the therapeutic efficacy of glioma vaccines based on allo- and syngeneic antigens and distinct immunological costimulation activators

    NARCIS (Netherlands)

    Stathopoulos, A.; Pretto, C.; Devillers, L.; Pierre, D.; Hofman, F.M.; Epstein, A.L.; Farghadani, H.; Kruse, C.A.; Jadus, M.R.; Chen, T.C.; Schijns, V.E.J.C.

    2012-01-01

    The efficacy of a various immunotherapeutic immunisation strategies for malignant glioma brain cancer was evaluated in the syngeneic CNS-1 Lewis rat glioma model. A prototype glioma cancer vaccine, which was composed of multivalent antigens derived from allogeneic and syngeneic cells and lysates,

  4. Target-specific activation of mast cells by immunoglobulin E reactive with a renal cell carcinoma-associated antigen

    NARCIS (Netherlands)

    Luiten, R. M.; Fleuren, G. J.; Warnaar, S. O.; Litvinov, S. V.

    1996-01-01

    Immunoglobulin E (IgE) that specifically binds to antigens present on carcinoma cells may represent a useful tool to combat carcinomas. Induction of an inflammatory response at the tumor site by tumor-specific IgE may result in reduced tumor growth and tumor regression. Local mast cells may be

  5. Delivery of protein antigens to the immune system by fusion-active virosomes : A comparison with liposomes and ISCOMs

    NARCIS (Netherlands)

    Bungener, L; Huckriede, A; Wilschut, J; Daemen, T

    The induction of effective cellular and humoral immune responses against protein antigens is of major importance in vaccination strategies against infectious diseases and cancer. Immunization with protein alone in general does not result in efficient induction of cytotoxic T lymphocyte (CTL) and

  6. Establishment and characterization of a cell based artificial antigen-presenting cell for expansion and activation of CD8+ T cells ex vivo.

    Science.gov (United States)

    Gong, Weijuan; Ji, Mingchun; Cao, Zhengfeng; Wang, Liheng; Qian, Yayun; Hu, Maozhi; Qian, Li; Pan, Xingyuan

    2008-02-01

    Artificial antigen-presenting cells are expected to stimulate the expansion and acquisition of optimal therapeutic features of T cells before infusion. Here CD32 that binds to a crystallizable fragment of IgG monoclonal antibody was genetically expressed on human K562 leukemia cells to provide a ligand for T-cell receptor. CD86 and 4-1BBL, which are ligands of co-stimulating receptors of CD28 and 4-1BB, respectively, were also expressed on K562 cells. Then we accomplished the artificial antigen-presenting cells by coupling K32/CD86/4-1BBL cell with OKT3 monoclonal antibody against CD3, named K32/CD86/4-1BBL/OKT3 cells. These artificial modified cells had the abilities of inducing CD8+ T cell activation, promoting CD8+ T cell proliferation, division, and long-term growth, inhibiting CD8+ T cell apoptosis, and enhancing CD8+ T cell secretion of IFN-gamma and perforin. Furthermore, antigen-specific cytotoxic T lymphocytes could be retained in the culture stimulated with K32/CD86/4-1BBL/OKT3 cells at least within 28 days. This approach was robust, simple, reproducible and economical for expansion and activation of CD8+ T cells and may have important therapeutic implications for adoptive immunotherapy.

  7. Delta9-tetrahydrocannabinol increases sequence-specific AP-1 DNA-binding activity and Fos-related antigens in the rat brain.

    Science.gov (United States)

    Porcella, A; Gessa, G L; Pani, L

    1998-05-01

    Delta-9-tetrahydrocannabinol (delta9-THC), the psychoactive principle of marijuana, has been shown to upregulate the mRNA levels of immediate-early genes in the rat brain. Using electrophoretic mobility-shift assay and one-dimensional Western blot, we here report that delta9-THC increases Activator protein-1 (AP-1) DNA-binding and Fos-related antigen activity in discrete areas of the rat brain. One hour after the intraperitoneal administration of delta9-THC at a dose of 10 or 15 mg/kg, AP-1 DNA-binding activity in the nucleus accumbens increased by 33 and 49%, respectively, while Western blot showed an increase in both c-Fos, FosB, Fra-1 (Fos-related antigen) and Fra-2. In the cingulate cortex and caudate-putamen, delta9-THC significantly increased AP-1 DNA-binding activity only at the highest dose used (57 and 71%, respectively). While in the caudate-putamen the increase in AP-1 DNA binding was mainly due to an elevation of the c-Fos and FosB proteins, the same phenomenon depended on the FosB, Fra-1 and Fra-2 peptides in the cingulate cortex. The effect of delta9-THC on the AP-1 DNA binding and the Fos-related antigens in the nucleus accumbens was blocked by the specific cannabinoid antagonist SR141716 A (3 mg/kg i.p.). delta9-THC failed to modify Specificity protein 1 (Sp1) DNA-binding activity. The results indicate that delta9-THC activates gene coding for AP-1 DNA-binding proteins by acting on cannabinoid receptors, and induces a different transcriptional program on the early-immediate gene of the Fos family, in different areas in the rat brain, suggesting that this mechanism might be involved in the central actions of cannabinoids.

  8. Antigenic fractions from Taenia crassiceps metacestodes obtained by hydrophobicity for the immunodiagnosis of active and inactive forms of neurocysticercosis in human cerebrospinal fluid samples.

    Science.gov (United States)

    da Silva, Gabriela B; Nunes, Daniela S; de Sousa, José Eduardo N; Gonçalves-Pires, Maria do R F; Levenhagen, Marcelo A; Costa-Cruz, Julia M

    2017-04-01

    This study aimed to evaluate the total extract of Taenia crassiceps metacestodes (TC) and its antigenic fractions obtained by Triton X-114 fractionation techniques, such as detergent (DC) and aqueous (AC), in the immunodiagnosis of human neurocysticercosis (NCC). Cerebrospinal fluid samples were divided into two groups: Group 1 (n=40), which was further divided into active (n=20) and inactive (n=20) NCC, and Group 2 (control group), which comprised 39 CSF samples from patients who had another neurological disorder, were suffering from other infectious diseases of the brain or had other parasitic infections. The total extracts and antigenic fractions were tested by enzyme-linked immunosorbent assay (ELISA) to detect human IgG anti-Taenia solium. T. crassiceps fractions (DC and AC) showed the same value of sensitivity (Se), 100%, for active and inactive NCC and a specificity (Sp) of 97.4%. The DS fraction obtained from T. solium showed 100% Se for active NCC, 95% Se for inactive NCC and a 92.3% Sp. The AS fraction obtained from T. solium showed 100% Se for both active and inactive NCC and a 94.9% Sp. There was a positive correlation between the total saline extract of T. crassiceps (TC) and T. solium (TS) and their fractions (DC, AC, DS and AS). Positive predictive value, negative predictive value, diagnostic efficiency and Youden index were calculated. In conclusion, these results demonstrated that detergent and aqueous fractions obtained from T. crassiceps metacestodes are important sources of specific antigens and are efficient for immunodiagnosis of active and inactive NCC. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

  9. Investigating the Functional Role of Prostate-Specific Membrane Antigen and Its Enzymatic Activity in Prostate Cancer Metastasis

    Science.gov (United States)

    2009-11-01

    7E11-C5. Cancer Res. 50: 6423-6429. 1990. 7. Wright GL Jr., Haley C, Beckett ML, Schellhammer PF. Expression of prostate-specific membrane antigen in...normal, benign, and malignant prostate tissues. Urol Oncol. 1:18-28. 1995. 8. Troyer JK, Beckett ML, Wright GL Jr. Detection and characterization of...mixed homogenates (data not shown). Thus, the aggre- gates form in intact cells, not after homogenization. Intracellular abundance of radio -labeled

  10. Exceptionally Potent Anti-Tumor Bystander Activity of an scFv:sTRAIL Fusion Protein with Specificity for EGP2 Toward Target Antigen-Negative Tumor Cells

    Directory of Open Access Journals (Sweden)

    Edwin Bremer

    2004-09-01

    Full Text Available Previously, we reported on the target cell-restricted fratricide apoptotic activity of scFvC54:sTRAIL, a fusion protein comprising human-soluble tumor necrosis factor-related apoptosis-inducing ligand (TRAIL genetically linked to the antibody fragment scFvC54 specific for the cell surface target antigen EGP2. In the present study, we report that the selective binding of scFvC54:sTRAIL to EGP2-positive target cells conveys an exceptionally potent pro-apoptotic effect toward neighboring tumor cells that are devoid of EGP2 expression (bystander cells. The anti-tumor bystander activity of scFvC54:sTRAIL was detectable at target-tobystander cell ratios as low as 1:100. Treatment in the presence of EGP2-blocking or TRAIL-neutralizing antibody strongly inhibited apoptosis in both target and bystander tumor cells. In the absence of target cells, bystander cell apoptosis induction was abrogated. The bystander apoptosis activity of scFvC54:sTRAIL did not require internalization, enzymatic conversion, diffusion, or communication (gap junctional intracellular communication between target and bystander cells. Furthermore, scFvC54:sTRAIL showed no detectable signs of innocent bystander activity toward freshly isolated blood cells. Further development of this new principle is warranted for approaches where cancer cells can escape from antibody-based therapy due to partial loss of target antigen expression.

  11. Prospective evaluation of a whole-blood test using Mycobacterium tuberculosis-specific antigens ESAT-6 and CFP-10 for diagnosis of active tuberculosis

    DEFF Research Database (Denmark)

    Ravn, Pernille; Munk, Martin E; Andersen, Ase B

    2005-01-01

    A new immunodiagnostic test based on the Mycobacterium tuberculosis-specific antigens CFP-10/ESAT-6(QFT-RD1) has been launched as an aid in the diagnosis of latent tuberculosis (TB) infection (LTBI). The aim of this study was to evaluate this test for the diagnosis of active TB. Eighty-two patients....... The accuracy of the QFT-RD1 test will vary with the prevalence of LTBI. We suggest that the QFT-RD1 test could be a very useful supplementary tool for the diagnosis of TB....

  12. Ligation of major histocompatibility complex class I antigens (MHC-I) prevents apoptosis induced by Fas or SAPK/JNK activation in T-lymphoma cells

    DEFF Research Database (Denmark)

    Lamberth, K; Claesson, M H

    2001-01-01

    Early apoptosis in Jurkat T-lymphoma cells was induced by agonistic anti-Fas Ab or by anisomycin which activates the stress kinases SAPK/JNK. Apoptosis was inhibited by ligation of major histocompatibility complex class I antigens (MHC-I). MHC-I ligation induced upregulation of the anti......-apoptotic Bcl-2 protein and stabilized the mitochondrial membrane potential (Deltapsim). MHC-I ligation also prevented downregulation of Bcl-2 and destabilization of Deltapsim induced by anti-Fas Ab treatment or anisomycin exposure. Studies on three different Jurkat cell mutants deficient for src p56(lck), ZAP...

  13. B cell antigen receptor-induced activation of an IRAK4-dependent signaling pathway revealed by a MALT1-IRAK4 double knockout mouse model

    Directory of Open Access Journals (Sweden)

    Dufner Almut

    2011-03-01

    Full Text Available Abstract Background The B cell antigen receptor (BCR and pathogen recognition receptors, such as Toll-like receptor 4 (TLR4, act in concert to control adaptive B cell responses. However, little is known about the signaling pathways that integrate BCR activation with intrinsic TLR4 stimulation. Antigen receptors initialize activation of the inducible transcription factor nuclear factor-κB (NF-κB via recruitment of the membrane-associated guanylate kinase caspase recruitment domain protein 11 (CARD11, the adapter molecule B cell CLL/lymphoma 10 (BCL10, and the "paracaspase" mucosa-associated lymphoid tissue lymphoma translocation gene 1 (MALT1 into lipid rafts. Upon BCR triggering, this activation strictly depends on BCL10, but not on MALT1, leading to the hypothesis that a MALT1-independent NF-κB activation pathway contributes to BCR-induced NF-κB activation downstream of BCL10. The identity of this pathway has remained elusive. Results Using genetic and biochemical approaches, we demonstrate that the IRAK4- and IRAK1-dependent TLR signaling branch is activated upon BCR triggering to induce partial NF-κB activation. BCR-induced MALT1-independent IκB degradation and B cell proliferation were inhibited in MALT1/IRAK4 double knockout B cells. Moreover, IRAK1 was recruited into lipid rafts upon BCR stimulation and activated following transient recruitment of IRAK4. Conclusion We propose that the observed crosstalk between BCR and TLR signaling components may contribute to the discrimination of signals that emanate from single and dual receptor engagement to control adaptive B cell responses.

  14. Soluble Human Leukocyte Antigen-G5 Activates Extracellular Signal-Regulated Protein Kinase Signaling and Stimulates Trophoblast Invasion

    OpenAIRE

    YiFan Guo; Cheuk-Lun Lee; Kam-Hei So; Jing Gao; Yeung, William S. B.; YuanQing Yao; Kai-Fai Lee

    2013-01-01

    Soluble human leukocyte antigen-G (HLA-G) is a non-classical class Ib HLA molecule that is secreted from blastocysts. Soluble HLA-G modulates the immune tolerance of the mother and can be used as a prognostic factor for the clinical pregnancy rate. However, the underlying mechanism of how soluble HLA-G5 affects pregnancy remains largely unknown. We hypothesized that soluble HLA-G5 promotes successful implantation and pregnancy by modulating trophoblast invasion through receptor binding and ac...

  15. Inhibition of soluble antigen-induced T cell proliferation by warm-reactive antibodies to activated T cells in systemic lupus erythematosus.

    Science.gov (United States)

    Yamada, A; Winfield, J B

    1984-12-01

    One of the fundamental immunologic characteristics of systemic lupus erythematosus (SLE) is a depressed T cell proliferative response to various specific and nonspecific stimuli. Both intrinsic cellular defect(s) and inhibitory influences of humoral factors, e.g., antilymphocyte autoantibodies or immune complexes, have been postulated to underly this functional abnormality. Because patient serum can induce SLE-like T cell dysfunction in normal cells, an extrinsic mechanism is probably responsible, but the nature and site of action of this humoral activity has not been defined. This laboratory recently described a novel antibody specific for activated T cells in SLE, which raised the possibility that suppression of T cell proliferation by SLE serum involved antibodies directed to surface determinants expressed during the process of activation. In experiments to examine this concept further, relatively warm-reactive antibodies to T cell blasts were found to inhibit strongly the well-characterized T cell response to tetanus toxoid. These antibodies were distinct from conventional cold-reactive IgM antibodies to resting T cells, which exhibited little inhibitory activity. Inhibition involved noncytotoxic effects on early activation events at the level of the responding T cell, which markedly reduced the expression of receptors for interleukin 2. Inhibitory effects on antigen-pulsed macrophages or on T cells already committed to proliferate were not demonstrable. Anti-T blast antibodies were characteristic of active SLE and were detected only occasionally in patients with inactive disease or non-SLE rheumatic disorders. Although the exact antigenic specificity was not identified, considerable evidence was obtained against the presence of antibodies to Ia and certain other surface determinants of functional relevance. Our observations concerning the suppressive effects of anti-T blast antibodies in SLE serum on the T cell response to tetanus toxoid should provide new

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

    DEFF Research Database (Denmark)

    Dam-Tuxen, R; Riise, Erik Skjold

    2009-01-01

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

  17. Modulation of endotoxicity of Shigella generalized modules for membrane antigens (GMMA) by genetic lipid A modifications: relative activation of TLR4 and TLR2 pathways in different mutants.

    Science.gov (United States)

    Rossi, Omar; Pesce, Isabella; Giannelli, Carlo; Aprea, Susanna; Caboni, Mariaelena; Citiulo, Francesco; Valentini, Sara; Ferlenghi, Ilaria; MacLennan, Calman Alexander; D'Oro, Ugo; Saul, Allan; Gerke, Christiane

    2014-09-05

    Outer membrane particles from Gram-negative bacteria are attractive vaccine candidates as they present surface antigens in their natural context. We previously developed a high yield production process for genetically derived particles, called generalized modules for membrane antigens (GMMA), from Shigella. As GMMA are derived from the outer membrane, they contain immunostimulatory components, especially lipopolysaccharide (LPS). We examined ways of reducing their reactogenicity by modifying lipid A, the endotoxic part of LPS, through deletion of late acyltransferase genes, msbB or htrB, in GMMA-producing Shigella sonnei and Shigella flexneri strains. GMMA with resulting penta-acylated lipid A from the msbB mutants showed a 600-fold reduced ability, and GMMA from the S. sonnei ΔhtrB mutant showed a 60,000-fold reduced ability compared with GMMA with wild-type lipid A to stimulate human Toll-like receptor 4 (TLR4) in a reporter cell line. In human peripheral blood mononuclear cells, GMMA with penta-acylated lipid A showed a marked reduction in induction of inflammatory cytokines (S. sonnei ΔhtrB, 800-fold; ΔmsbB mutants, 300-fold). We found that the residual activity of these GMMA is largely due to non-lipid A-related TLR2 activation. In contrast, in the S. flexneri ΔhtrB mutant, a compensatory lipid A palmitoleoylation resulted in GMMA with hexa-acylated lipid A with ∼10-fold higher activity to stimulate peripheral blood mononuclear cells than GMMA with penta-acylated lipid A, mostly due to retained TLR4 activity. Thus, for use as vaccines, GMMA will likely require lipid A penta-acylation. The results identify the relative contributions of TLR4 and TLR2 activation by GMMA, which need to be taken into consideration for GMMA vaccine development. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  18. The prognostic value of oncogenic antigen 519 (OA-519) expression and proliferative activity detected by antibody MIB-1 in node-negative breast cancer

    DEFF Research Database (Denmark)

    Jensen, V; Ladekarl, M; Holm-Nielsen, P

    1995-01-01

    The prognostic value of oncogenic antigen 519 (OA-519) expression and tumour proliferative activity was evaluated in a retrospective series of 118 patients with low-risk breast cancer. Low risk was defined as negative axillary nodes, tumour diameter ... of invasion of skin or deep fascia (= T1N0M0 and T2N0M0). The median follow-up time was 104 months (range 5-143 months). Immunohistochemical analysis of OA-519 expression was performed on formalin-fixed, paraffin-embedded tissue. The proliferative activity was estimated using a Ki-67 equivalent monoclonal...... analysis, both the MIB-1 index and OA-519 expression were of independent prognostic value (2p cancer who might benefit from adjuvant therapy....

  19. Preparation and evaluation of monoclonal antibodies against chlamydial protease-like activity factor to detect Chlamydia pneumoniae antigen in early pediatric pneumonia.

    Science.gov (United States)

    Zheng, J; Ding, T; Chen, Z; Fang, H; Li, H; Lu, H; Wu, Y

    2015-07-01

    Chlamydia pneumoniae causes diseases in humans, including community-acquired pneumonia, bronchitis, and sinusitis. It is also associated with atherosclerosis, coronary heart disease, and hyperlipidemia. In this study, we investigated novel materials with which to develop a sensitive and specific method to identify early C. pneumoniae infection, to allow more effective clinical treatment and prevention. We prepared novel monoclonal antibodies (mAbs) against a recombinant protein equivalent to the immunodominant region of chlamydial protease-like activity factor (CPAF) from C. pneumoniae. The mAbs specifically reacted with the endogenous CPAF antigen of the C. pneumoniae type strain in immunoblotting and indirect immunofluorescence (IIF) assays, but did not react with C. trachomatis type strains or genital secretions from patients with acute C. trachomatis infection. The mAb with the highest titer was used to develop a new IIF assay and enzyme-linked immunosorbent assay (ELISA) to detect the C. pneumoniae antigen in clinical specimens from child patients suspected of pneumonia. The sensitivity, specificity, and concordance rate of the mAb-based IIF and ELISA tests were compared with those of polymerase chain reaction (PCR). Our results show that these mAbs have excellent specificity and may be used to develop new screening tools for the diagnosis of early pediatric pneumonia.

  20. A robust dry reagent lateral flow assay for diagnosis of active schistosomiasis by detection of Schistosoma circulating anodic antigen.

    Science.gov (United States)

    van Dam, Govert J; de Dood, Claudia J; Lewis, Melanie; Deelder, André M; van Lieshout, Lisette; Tanke, Hans J; van Rooyen, Louis H; Corstjens, Paul L A M

    2013-10-01

    An earlier reported laboratory assay, performed in The Netherlands, to diagnose Schistosoma infections by detection of the parasite antigen CAA in serum was converted to a more user-friendly format with dry reagents. The improved assay requires less equipment and allows storage and worldwide shipping at ambient temperature. Evaluation of the new assay format was carried out by local staff at Ampath Laboratories, South Africa. The lateral flow (LF) based assay utilized fluorescent ultrasensitive up-converting phosphor (UCP) reporter particles, to be read by a portable reader (UPlink) that was also provided to the laboratory. Over a period of 18 months, about 2000 clinical samples were analyzed prospectively in parallel with a routinely carried out CAA-ELISA. LF test results and ELISA data correlated very well at CAA concentrations above 300 pg/mL serum. At lower concentrations the UCP-LF test indicates a better performance than the ELISA. The UCP-LF strips can be stored as a permanent record as the UCP label does not fade. At the end of the 18 months testing period, LF strips were shipped back to The Netherlands where scan results obtained in South Africa were validated with different UCP scanning equipment including a novel, custom developed, small lightweight UCP strip reader (UCP-Quant), well suited for testing in low resource settings. The dry format UCP-LF assay was shown to provide a robust and easy to use format for rapid testing of CAA antigen in serum. It performed at least as good as the ELISA with respect to sensitivity and specificity, and was found to be superior with respect to speed and simplicity of use. Worldwide shipping at ambient temperature of the assay reagents, and the availability of small scanners to analyze the CAA UCP-LF strip, are two major steps towards point-of-care (POC) applications in remote and resource poor environments to accurately identify low (30 pg CAA/mL serum; equivalent to about 10 worm pairs) to heavy Schistosoma

  1. Effect of the hepatitis B virus S‑ecdCD40L vaccine therapy in HBV transgenic mice: A vaccine‑induced activation of antigen presenting dendritic cells.

    Science.gov (United States)

    Guan, Huaqin; Lan, Songsong; Wu, Jinming; Tang, Binbin; Xu, Yin

    2017-11-01

    The classical hepatitis B virus (HBV) DNA vaccination plasmid only encodes for a single viral antigen, either the S or the PreS2/S antigen. Many strategies have been employed to improve the effect of these DNA vaccines. Our previous study identified that the fusion gene, HBV S‑ecd cluster of differentiation 40 ligand (CD40L), may promote the activation of dendritic cells (DCs) and enhance their function in vitro. In the current study, the effect of HBV S‑ecdCD40L vaccine therapy on liver DCs was investigated, and its therapeutic potential in HBV transgenic (HBV‑Tg) mice was evaluated. The eukaryotic expression plasmid, pcDNA3.1‑S‑ecdCD40L, was constructed by inserting the HBV S gene and mouse CD40L gene into the vector, pcDNA3.1 (+). HBV‑Tg mice were immunized with pcDNA3.1‑S‑ecdCD40L, pcDNA3.1‑S, pcDNA3.1 or PBS. Following this, immunophenotyping, cytokine production and T‑cell activation were analyzed in the CD11c‑enriched DC population obtained from the liver. Vaccine efficacy was further assessed by the detection of serological and biochemical parameters. When comparing with other control groups, DCs from HBV‑Tg mice immunized with pcDNA3.1‑S‑ecdCD40L exhibited increased expression of immunologically important cell molecules (CD86 and major histocompatibility complex class II), pro‑inflammatory cytokines (interleukin‑12), and enhanced capacity to promote allogeneic T‑cell proliferation. Furthermore, the HBV S‑ecdCD40L vaccine resulted in a significant inhibition of HBV DNA replication and downregulation of the hepatitis B virus surface antigen (HBsAg) in HBV‑Tg mice, without obvious liver injury. In conclusion, the HBV S‑ecdCD40L vaccine may be a feasible strategy for chronic HBV immunotherapy via promoting DC activation and function.

  2. Antigens of Bordetella pertussis. IV. Effect of heat, merthiolate, and formaldehyde on histamine-sensitizing factor and protective activity of soluble extracts from Bordetella pertussi.s.

    Science.gov (United States)

    Munoz, J; Hestekin, B M

    1966-06-01

    Munoz, J. (Rocky Mountain Laboratory, Hamilton, Mont.), and B. M. Hestekin. Antigens of Bordetella pertussis. IV. Effect of heat, Merthiolate, and formaldehyde on histamine-sensitizing factor and protective activity of soluble extracts from Bordetella pertussis. J. Bacteriol. 91:2175-2179. 1966.-Both histamine-sensitizing and protective activities of soluble preparations from Bordetella pertussis cells are destroyed by heating at 80 C for 0.5 hr. The histamine-sensitizing activity appeared to be more susceptible to inactivation by heat than the protective activity. Formaldehyde in a final concentration of 0.5% rapidly diminished the histamine-sensitizing ability of saline extract (SE) held at 37 C. The protective activity was clearly more resistant to inactivation by formaldehyde at similar temperature. The inactivating action of formaldehyde was slower when the concentration of SE was increased or when the mixture was kept at 2 to 5 C. Merthiolate in a final concentration of 1:10,000 had no demonstrable deleterious effects on either protective or histamine-sensitizing activity of SE.

  3. Antigen-specific IL-23/17 pathway activation by murine semi-mature DC-like cells

    Energy Technology Data Exchange (ETDEWEB)

    Nagasaka, Shinya; Iwasaki, Takumi; Okano, Tomoko [Department of Biological Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda-shi, Chiba 278-8510 (Japan); Chiba, Joe, E-mail: chibaj@rs.noda.tus.ac.jp [Department of Biological Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda-shi, Chiba 278-8510 (Japan)

    2009-09-11

    We analyzed the phenotype and function of bone marrow-derived dendritic cells (DCs) induced in vitro without using any serum during the late stage of cultivation. These 'serum-free' DCs (SF-DCs) possessed the ability to induce T cell proliferation as well as antibody responses, indicating that they were functional DCs. Surprisingly, the SF-DCs akin to semi-mature DCs in terms of both phenotypic and functional characteristics. The SF-DCs did not produce IL-12 but produced large amounts of IL-23 following lipopolysaccharide stimulation. The antigen-specific production of IL-17 by CD4{sup +} T cells co-cultured with OVA-loaded SF-DCs was significantly higher than that with OVA-loaded conventional DCs. These results suggest that SF-DCs tend to produce IL-23 and can consequently induce the IL-17 producing CD4{sup +} T cells. The semi-mature DC-like cells reported here will be useful vehicles for DC immunization and might contribute to studies on the possible involvement of semi-mature DCs in Th17 cell differentiation.

  4. Structure-activity relations of water-in-oil vaccine formulations and induced antigen-specific antibody responses.

    Science.gov (United States)

    Jansen, Theo; Hofmans, Marij P M; Theelen, Marc J G; Schijns, Virgil E J C

    2005-01-11

    Water-in-oil (W/O) emulsions are known as most effective adjuvants to generate high and durable antibody responses to vaccine antigens following a single immunization. However, their structural requirements remain poorly understood. Here we addressed the significance of certain pharmaceutical characteristics including water/oil ratios--ranging from 60/40 to 30/70 (w/w(%))--droplet size and type of oil, i.e. non-metabolizable (mineral oil) versus metabolizable (Miglyol 840). Stability of emulsions was accomplished by the use of a polymeric emulsifier. Distinct W/O emulsions were formulated with inactivated (i) infectious bronchitis virus (iIBV) and Newcastle disease virus (iNDV), and evaluated in immunized chickens for magnitude and duration of in vivo antiviral antibody formation and local reactions. A high mineral oil content proved most effective for antibody response formation. In general, a larger droplet size evoked higher antibody responses for both oil types. Inoculum residues proved lower using biodegradable Miglyol, when compared to mineral oil, for all emulsion variants. Especially water-to-oil ratio and droplet size may provide useful parameters for improving (antiviral) antibody production by W/O emulsions.

  5. Epstein-Barr virus LMP2A signaling in statu nascendi mimics a B cell antigen receptor-like activation signal

    Directory of Open Access Journals (Sweden)

    Engels Niklas

    2012-04-01

    Full Text Available Abstract Background The latent membrane protein (LMP 2A of Epstein-Barr virus (EBV is expressed during different latency stages of EBV-infected B cells in which it triggers activation of cytoplasmic protein tyrosine kinases. Early studies revealed that an immunoreceptor tyrosine-based activation motif (ITAM in the cytoplasmic N-terminus of LMP2A can trigger a transient increase of the cytosolic Ca2+ concentration similar to that observed in antigen-activated B cells when expressed as a chimeric transmembrane receptor. Even so, LMP2A was subsequently ascribed an inhibitory rather than an activating function because its expression seemed to partially inhibit B cell antigen receptor (BCR signaling in EBV-transformed B cell lines. However, the analysis of LMP2A signaling has been hampered by the lack of cellular model systems in which LMP2A can be studied without the influence of other EBV-encoded factors. Results We have reanalyzed LMP2A signaling using B cells in which LMP2A is expressed in an inducible manner in the absence of any other EBV signaling protein. This allowed us for the first time to monitor LMP2A signaling in statu nascendi as it occurs during the EBV life cycle in vivo. We show that mere expression of LMP2A not only stimulated protein tyrosine kinases but also induced phospholipase C-γ2-mediated Ca2+ oscillations followed by activation of the extracellular signal-regulated kinase (Erk mitogen-activated protein kinase pathway and induction of the lytic EBV gene bzlf1. Furthermore, expression of the constitutively phosphorylated LMP2A ITAM modulated rather than inhibited BCR-induced Ca2+ mobilization. Conclusion Our data establish that LMP2A expression has a function beyond the putative inhibition of the BCR by generating a ligand-independent cellular activation signal that may provide a molecular switch for different EBV life cycle stages and most probably contributes to EBV-associated lymphoproliferative disorders.

  6. B-cell maturation antigen (BCMA) activation exerts specific proinflammatory effects in normal human keratinocytes and is preferentially expressed in inflammatory skin pathologies.

    Science.gov (United States)

    Alexaki, Vassilia-Ismini; Pelekanou, Vassiliki; Notas, George; Venihaki, Maria; Kampa, Marilena; Dessirier, Valérie; Sabour-Alaoui, Sanaa; Stathopoulos, Efstathios N; Tsapis, Andreas; Castanas, Elias

    2012-02-01

    TNFα is known to be expressed in human skin, regulating immune-related responses. Here we report that human normal skin keratinocytes express the members of the TNF superfamily members A proliferation-inducing ligand (APRIL; TNFSF13), B cell-activating factor (BAFF; TNFSF13B), and their receptors, B cell maturation antigen (BCMA; TNFRSF17) and transmembrane activator, calcium-modulator, and cyclophilin ligand interactor (TACI; TNFRSF13B), in a distinct spatial pattern. Our data show a differential expression of these molecules within epidermal layers and skin appendages, whereas the BAFF-specific receptor BAFFR (TNFRSF13C) is absent. Importantly, APRIL and BCMA but not BAFF or TACI are up-regulated in inflammatory skin lesions of psoriasis and squamous cell carcinomas. To explore the functional significance of this system in the skin, we assayed these receptors and ligands in cultured primary keratinocytes and HaCaT cells. We show that both cell types express BAFF, APRIL, BCMA, and TACI. Furthermore, APRIL and/or BAFF trigger nuclear factor-κB activation and IL-6 and granulocyte macrophage colony-stimulating factor (GM-CSF) expression through functional BCMA receptors, an activation inhibited by anti-BCMA short hairpin RNA. However, BAFF and/or APRIL do not induce IL-8 or TNFα production. Our data advance BCMA as an inflammation-related TNFSFR member in keratinocytes, of potential importance in the management of inflammatory skin conditions.

  7. Stimulation of 3′→5′ Exonuclease and 3′-Phosphodiesterase Activities of Yeast Apn2 by Proliferating Cell Nuclear Antigen

    Science.gov (United States)

    Unk, Ildiko; Haracska, Lajos; Gomes, Xavier V.; Burgers, Peter M. J.; Prakash, Louise; Prakash, Satya

    2002-01-01

    The Apn2 protein of Saccharomyces cerevisiae contains 3′→5′ exonuclease and 3′-phosphodiesterase activities, and these activities function in the repair of DNA strand breaks that have 3′-damaged termini and which are formed in DNA by the action of oxygen-free radicals. Apn2 also has an AP endonuclease activity and functions in the removal of abasic sites from DNA. Here, we provide evidence for the physical and functional interaction of Apn2 with proliferating cell nuclear antigen (PCNA). As indicated by gel filtration and two-hybrid studies, Apn2 interacts with PCNA both in vitro and in vivo and mutations in the consensus PCNA-binding motif of Apn2 abolish this interaction. Importantly, PCNA stimulates the 3′→5′ exonuclease and 3′-phosphodiesterase activities of Apn2. We have examined the involvement of the interdomain connector loop (IDCL) and of the carboxy-terminal domain of PCNA in Apn2 binding and found that Apn2 binds PCNA via distinct domains dependent upon whether the binding is in the absence or presence of DNA. In the absence of DNA, Apn2 binds PCNA through its IDCL domain, whereas in the presence of DNA, when PCNA has been loaded onto the template-primer junction by replication factor C, the C-terminal domain of PCNA mediates the binding. PMID:12192046

  8. DNA hypomethylation-mediated activation of Cancer/Testis Antigen 45 (CT45) genes is associated with disease progression and reduced survival in epithelial ovarian cancer.

    Science.gov (United States)

    Zhang, Wa; Barger, Carter J; Link, Petra A; Mhawech-Fauceglia, Paulette; Miller, Austin; Akers, Stacey N; Odunsi, Kunle; Karpf, Adam R

    2015-01-01

    Epithelial ovarian cancer (EOC) is a highly lethal malignancy due to a lack of early detection approaches coupled with poor outcomes for patients with clinically advanced disease. Cancer-testis (CT) or cancer-germline genes encode antigens known to generate spontaneous anti-tumor immunity in cancer patients. CT45 genes are a recently discovered 6-member family of X-linked CT genes with oncogenic function. Here, we determined CT45 expression in EOC and fully defined its epigenetic regulation by DNA methylation. CT45 was silent and hypermethylated in normal control tissues, but a large subset of EOC samples showed increased CT45 expression in conjunction with promoter DNA hypomethylation. In contrast, copy number status did not correlate with CT45 expression in the TCGA database for EOC. CT45 promoter methylation inversely correlated with both CT45 mRNA and protein expression, the latter determined using IHC staining of an EOC TMA. CT45 expression was increased and CT45 promoter methylation was decreased in late-stage and high-grade EOC, and both measures were associated with poor survival. CT45 hypomethylation was directly associated with LINE-1 hypomethylation, and CT45 was frequently co-expressed with other CT antigen genes in EOC. Decitabine treatment induced CT45 mRNA and protein expression in EOC cells, and promoter transgene analyses indicated that DNA methylation directly represses CT45 promoter activity. These data verify CT45 expression and promoter hypomethylation as possible prognostic biomarkers, and suggest CT45 as an immunological or therapeutic target in EOC. Treatment with decitabine or other epigenetic modulators could provide a means for more effective immunological targeting of CT45.

  9. The mechanisms of activation of normal human serum complement by Escherichia coli strains with K1 surface antigen.

    Science.gov (United States)

    Bugla-Płoskońska, G; Cisowska, A; Karpińska, K; Jankowski, S; Doroszkiewicz, W

    2006-01-01

    Ten E. coli K1 strains isolated from the urine of children with urinary tract infections were sensitive to the bactericidal action of normal human serum (NHS). The role of the particular mechanisms of complement activation was determined in the process of killing these strains, showing variable sensitivity to the bactericidal action of NHS; three mechanisms of activation of human complement were observed. Important role of alternative pathway activation in the bactericidal action of NHS against E. coli K1 strains independent of the classical and lectin pathways was not established.

  10. Early Signaling in Primary T Cells Activated by Antigen Presenting Cells Is Associated with a Deep and Transient Lamellal Actin Network.

    Directory of Open Access Journals (Sweden)

    Kole T Roybal

    Full Text Available Cellular signaling transduction critically depends on molecular interactions that are in turn governed by dynamic subcellular distributions of the signaling system components. Comprehensive insight into signal transduction requires an understanding of such distributions and cellular structures driving them. To investigate the activation of primary murine T cells by antigen presenting cells (APC we have imaged more than 60 signaling intermediates during T cell stimulation with microscopy across resolution limits. A substantial number of signaling intermediates associated with a transient, wide, and actin-associated lamellum extending from an interdigitated T cell:APC interface several micrometers into the T cell, as characterized in detail here. By mapping the more than 60 signaling intermediates onto the spatiotemporal features of cell biological structures, the lamellum and other ones previously described, we also define distinct spatial and temporal characteristics of T cell signal initiation, amplification, and core signaling in the activation of primary T cells by APCs. These characteristics differ substantially from ones seen when T cells are activated using common reductionist approaches.

  11. Interaction of proliferating cell nuclear antigen with PMS2 is required for MutLα activation and function in mismatch repair

    Science.gov (United States)

    Genschel, Jochen; Kadyrova, Lyudmila Y.; Iyer, Ravi R.; Dahal, Basanta K.; Kadyrov, Farid A.; Modrich, Paul

    2017-01-01

    Eukaryotic MutLα (mammalian MLH1–PMS2 heterodimer; MLH1–PMS1 in yeast) functions in early steps of mismatch repair as a latent endonuclease that requires a mismatch, MutSα/β, and DNA-loaded proliferating cell nuclear antigen (PCNA) for activation. We show here that human PCNA and MutLα interact specifically but weakly in solution to form a complex of approximately 1:1 stoichiometry that depends on PCNA interaction with the C-terminal endonuclease domain of the MutLα PMS2 subunit. Amino acid substitution mutations within a PMS2 C-terminal 721QRLIAP motif attenuate or abolish human MutLα interaction with PCNA, as well as PCNA-dependent activation of MutLα endonuclease, PCNA- and DNA-dependent activation of MutLα ATPase, and MutLα function in in vitro mismatch repair. Amino acid substitution mutations within the corresponding yeast PMS1 motif (723QKLIIP) reduce or abolish mismatch repair in vivo. Coupling of a weak allele within this motif (723AKLIIP) with an exo1Δ null mutation, which individually confer only weak mutator phenotypes, inactivates mismatch repair in the yeast cell. PMID:28439008

  12. A novel strategy for the development of selective active-site inhibitors of the protein tyrosine phosphatase-like proteins islet-cell antigen 512 (IA-2) and phogrin (IA-2 beta)

    DEFF Research Database (Denmark)

    Drake, P.G.; Peters, Günther H.j.; Andersen, H.S.

    2003-01-01

    Islet-cell antigen 512 (IA-2) and phogrin (IA-2) are atypical members of he receptor protein tyrosine phosphatase (PTP) family that are characterized by a lack of activity against conventional PTP substrates. The physiological role(s) of these proteins remain poorly defined, although recent studi...

  13. Effect of physical activity and sedentary behavior on serum prostate-specific antigen concentrations: results from the National Health and Nutrition Examination Survey (NHANES), 2003-2006.

    Science.gov (United States)

    Loprinzi, Paul D; Kohli, Manish

    2013-01-01

    To examine the association between accelerometer-derived sedentary and physical activity and prostate-specific antigen (PSA) in a nationally representative sample of men in the United States. Data from the 2003-2004 and 2005-2006 National Health and Nutrition Examination Survey cycles were used in the present study, with data from 1672 adult male participants used in the analyses. The manuscript was prepared between July 7, 2012, and September 26, 2012. Sedentary and physical activity was objectively measured using an accelerometer. Covariates included various demographic, dietary, biological, and immunologic variables including age, height, weight, body mass index, race/ethnicity, marital status, education, and poverty-income ratio; dietary fiber, fat, protein, and carbohydrate intake and total energy intake; vitamin C and vitamin E; alcohol intake; medication use; concentrations of cotinine, total cholesterol, and high-density lipoprotein cholesterol; blood pressure (elevated or not elevated); diabetes; C-reactive protein; and white blood cell count and number of basophils and eosinophils. Only after controlling for all covariates, for every 1-hour increase in sedentary behavior, participants were 16% more likely to have an elevated PSA concentration (odds ratio, 1.16 [95% CI, 1.06-1.27]; P=.001). For every 1-hour increase in light physical activity, participants were 18% less likely to have an elevated PSA concentration (odds ratio, 0.82 [95% CI, 0.68-1.00]; P=.05). Individuals who engage in more sedentary behavior and lower levels of light physical activity have higher PSA concentrations. Future studies are needed to better identify the potential underlying mechanisms delineating the association between sedentary and physical activity and PSA concentration. Copyright © 2013 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.

  14. Primed antigen-specific CD4+ T cells are required for NK cell activation in vivo upon Leishmania major infection.

    Science.gov (United States)

    Bihl, Franck; Pecheur, Julien; Bréart, Béatrice; Poupon, Gwenola; Cazareth, Julie; Julia, Valérie; Glaichenhaus, Nicolas; Braud, Véronique M

    2010-08-15

    The ability of NK cells to rapidly produce IFN-gamma is an important innate mechanism of resistance to many pathogens including Leishmania major. Molecular and cellular components involved in NK cell activation in vivo are still poorly defined, although a central role for dendritic cells has been described. In this study, we demonstrate that Ag-specific CD4(+) T cells are required to initiate NK cell activation early on in draining lymph nodes of L. major-infected mice. We show that early IFN-gamma secretion by NK cells is controlled by IL-2 and IL-12 and is dependent on CD40/CD40L interaction. These findings suggest that newly primed Ag-specific CD4(+) T cells could directly activate NK cells through the secretion of IL-2 but also indirectly through the regulation of IL-12 secretion by dendritic cells. Our results reveal an unappreciated role for Ag-specific CD4(+) T cells in the initiation of NK cell activation in vivo upon L. major infection and demonstrate bidirectional regulations between innate and adaptive immunity.

  15. Coordinated activation of candidate proto-oncogenes and cancer testes antigens via promoter demethylation in head and neck cancer and lung cancer.

    Directory of Open Access Journals (Sweden)

    Ian M Smith

    Full Text Available Epigenetic alterations have been implicated in the pathogenesis of solid tumors, however, proto-oncogenes activated by promoter demethylation have been sporadically reported. We used an integrative method to analyze expression in primary head and neck squamous cell carcinoma (HNSCC and pharmacologically demethylated cell lines to identify aberrantly demethylated and expressed candidate proto-oncogenes and cancer testes antigens in HNSCC.We noted coordinated promoter demethylation and simultaneous transcriptional upregulation of proto-oncogene candidates with promoter homology, and phylogenetic footprinting of these promoters demonstrated potential recognition sites for the transcription factor BORIS. Aberrant BORIS expression correlated with upregulation of candidate proto-oncogenes in multiple human malignancies including primary non-small cell lung cancers and HNSCC, induced coordinated proto-oncogene specific promoter demethylation and expression in non-tumorigenic cells, and transformed NIH3T3 cells.Coordinated, epigenetic unmasking of multiple genes with growth promoting activity occurs in aerodigestive cancers, and BORIS is implicated in the coordinated promoter demethylation and reactivation of epigenetically silenced genes in human cancers.

  16. Coordinated activation of candidate proto-oncogenes and cancer testes antigens via promoter demethylation in head and neck cancer and lung cancer.

    Science.gov (United States)

    Smith, Ian M; Glazer, Chad A; Mithani, Suhail K; Ochs, Michael F; Sun, Wenyue; Bhan, Sheetal; Vostrov, Alexander; Abdullaev, Ziedulla; Lobanenkov, Victor; Gray, Andrew; Liu, Chunyan; Chang, Steven S; Ostrow, Kimberly L; Westra, William H; Begum, Shahnaz; Dhara, Mousumi; Califano, Joseph

    2009-01-01

    Epigenetic alterations have been implicated in the pathogenesis of solid tumors, however, proto-oncogenes activated by promoter demethylation have been sporadically reported. We used an integrative method to analyze expression in primary head and neck squamous cell carcinoma (HNSCC) and pharmacologically demethylated cell lines to identify aberrantly demethylated and expressed candidate proto-oncogenes and cancer testes antigens in HNSCC. We noted coordinated promoter demethylation and simultaneous transcriptional upregulation of proto-oncogene candidates with promoter homology, and phylogenetic footprinting of these promoters demonstrated potential recognition sites for the transcription factor BORIS. Aberrant BORIS expression correlated with upregulation of candidate proto-oncogenes in multiple human malignancies including primary non-small cell lung cancers and HNSCC, induced coordinated proto-oncogene specific promoter demethylation and expression in non-tumorigenic cells, and transformed NIH3T3 cells. Coordinated, epigenetic unmasking of multiple genes with growth promoting activity occurs in aerodigestive cancers, and BORIS is implicated in the coordinated promoter demethylation and reactivation of epigenetically silenced genes in human cancers.

  17. A case report on very late onset mania

    Directory of Open Access Journals (Sweden)

    Manjunadh Muraleedharan

    2017-06-01

    Full Text Available Diagnosing primary psychiatric disorder in elderly is a challenge considering the high prevalence of neurological and other medical diseases presenting with psychiatric manifestation. The first episode of mania occurring after the age of 80 years is extremely rare. We report a case of an 88-year-old married Hindu male educated up to fifth standard from rural background and lower socioeconomic status presenting with first episode mania, diagnosed using the tenth revision of the International Statistical Classification of Diseases and Related Health Problems (ICD-10 criteria. Secondary causes were ruled out and successfully treated with low dose olanzapine.

  18. Very late bare-metal stent thrombosis, rare but stormy!

    LENUS (Irish Health Repository)

    Ali, Mohammed

    2011-08-01

    Recurrent in-stent thrombosis is rarely reported, with catastrophic clinical consequences of either acute coronary syndrome or death. We present a case of recurrent in-stent thrombosis with its outcome and a concise literature review.

  19. Carbohydrate antigen microarrays.

    Science.gov (United States)

    Wang, Denong

    2012-01-01

    This chapter describes one of my laboratory's working protocols for carbohydrate-based microarrays. Using a standard microarray spotter, we print carbohydrate antigens directly on the nitrocellulose-coated bioarray substrates. Because these substrates support noncovalent immobilization of many spotted antigens, in general no chemical modification of the antigen is needed for microarray production. Thus, this bioarray platform is technically simple and applicable for high-throughput construction of carbohydrate antigen microarrays. A number of nitrocellulose-coated glass slides with different technical characteristics are commercially available. Given the structural diversity of carbohydrate antigens, examining each antigen preparation to determine the efficacy of its immobilization in a given type of substrate and the surface display of the desired glycoepitopes in a microarray assay is essential.

  20. Association of Single Nucleotide Polymorphisms in the ST3GAL4 Gene with VWF Antigen and Factor VIII Activity.

    Directory of Open Access Journals (Sweden)

    Jaewoo Song

    Full Text Available VWF is extensively glycosylated with biantennary core fucosylated glycans. Most N-linked and O-linked glycans on VWF are sialylated. FVIII is also glycosylated, with a glycan structure similar to that of VWF. ST3GAL sialyltransferases catalyze the transfer of sialic acids in the α2,3 linkage to termini of N- and O-glycans. This sialic acid modification is critical for VWF synthesis and activity. We analyzed genetic and phenotypic data from the Atherosclerosis Risk in Communities (ARIC study for the association of single nucleotide polymorphisms (SNPs in the ST3GAL4 gene with plasma VWF levels and FVIII activity in 12,117 subjects. We also analyzed ST3GAL4 SNPs found in 2,535 subjects of 26 ethnicities from the 1000 Genomes (1000G project for ethnic diversity, SNP imputation, and ST3GAL4 haplotypes. We identified 14 and 1,714 ST3GAL4 variants in the ARIC GWAS and 1000G databases respectively, with 46% being ethnically diverse in their allele frequencies. Among the 14 ST3GAL4 SNPs found in ARIC GWAS, the intronic rs2186717, rs7928391, and rs11220465 were associated with VWF levels and with FVIII activity after adjustment for age, BMI, hypertension, diabetes, ever-smoking status, and ABO. This study illustrates the power of next-generation sequencing in the discovery of new genetic variants and a significant ethnic diversity in the ST3GAL4 gene. We discuss potential mechanisms through which these intronic SNPs regulate ST3GAL4 biosynthesis and the activity that affects VWF and FVIII.

  1. Herpes simplex virus antigens directly activate NK cells via TLR2, thus facilitating their presentation to CD4 T lymphocytes.

    Science.gov (United States)

    Kim, Min; Osborne, Naomi R; Zeng, Weiguang; Donaghy, Heather; McKinnon, Kay; Jackson, David C; Cunningham, Anthony L

    2012-05-01

    NK cells infiltrate human herpetic lesions, but their role has been underexplored. HSV can stimulate innate immune responses via surface TLR2, which is expressed on monocyte-derived dendritic cells (DCs) and NK cells. In this study, UV-inactivated HSV1/2 and immunodominant HSV2 glycoprotein D peptides conjugated to the TLR2 agonist dipalmitoyl-S-glyceryl cysteine stimulated CD4 T lymphocyte IFN-γ responses within PBMCs or in coculture with monocyte-derived DCs. NK cells contributed markedly to the PBMC responses. Furthermore, NK cells alone were activated directly by both Ags, also upregulating HLA-DR and HLA-DQ and then they activated autologous CD4 T lymphocytes. Using Transwells, Ag-stimulated NK cells and CD4 T lymphocytes were shown to interact through both cell-to-cell contact and cytokines, differing in relative importance in different donors. A distinct immunological synapse between Ag-stimulated NK cells and CD4 T lymphocytes was observed, indicating the significance of their cell-to-cell contact. A large proportion (57%) of NK cells was also in contact with CD4 T lymphocytes in the dermal infiltrate of human recurrent herpetic lesions. Thus, NK cells stimulated by TLR2-activating HSV Ags can present Ag alone or augment the role of DCs in vitro and perhaps in herpetic lesions or draining lymph nodes. In addition to DCs, NK cells should be considered as targets for adjuvants during HSV vaccine development.

  2. Novel CD47: SIRPα dependent mechanism for the activation of STAT3 in antigen-presenting cell.

    Directory of Open Access Journals (Sweden)

    Natan Toledano

    Full Text Available Cell surface CD47 interacts with its receptor, signal-regulatory-protein α (SIRPα that is expressed predominantly on macrophages, to inhibit phagocytosis of normal, healthy cells. This "don't eat me" signal is mediated through tyrosine phosphorylation of SIRPα at the cytoplasmic ITIM motifs and the recruitment of the phosphatase, SHP-1. We previously revealed a novel mechanism for the activation of the STAT3 pathway and the regulation of human APC maturation and function that is based on cell:cell interaction. In this study, we present evidence supporting the notion that CD47:SIRPα serves as a cell surface receptor: ligand pair involved in this contact-dependent STAT3 activation and regulation of APC maturation. We show that upon co-culturing APC with various primary and tumor cell lines STAT3 phosphorylation and IL-10 expression are induced, and such regulation could be suppressed by specific CD47 siRNAs and shRNAs. Significantly, >50% reduction in CD47 expression abolished the contact-dependent inhibition of T cell activation. Furthermore, co-immunoprecipitation experiments revealed a physical association between SIRPα and STAT3. Thus, we suggest that in addition to signaling through the ITIM-SHP-1 complex that transmit an anti-phagocytotic, CD47:SIRPα also triggers STAT3 signaling that is linked to an immature APC phenotype and peripheral tolerance under steady state and pathological conditions.

  3. Novel CD47: SIRPα dependent mechanism for the activation of STAT3 in antigen-presenting cell.

    Science.gov (United States)

    Toledano, Natan; Gur-Wahnon, Devorah; Ben-Yehuda, Adi; Rachmilewitz, Jacob

    2013-01-01

    Cell surface CD47 interacts with its receptor, signal-regulatory-protein α (SIRPα) that is expressed predominantly on macrophages, to inhibit phagocytosis of normal, healthy cells. This "don't eat me" signal is mediated through tyrosine phosphorylation of SIRPα at the cytoplasmic ITIM motifs and the recruitment of the phosphatase, SHP-1. We previously revealed a novel mechanism for the activation of the STAT3 pathway and the regulation of human APC maturation and function that is based on cell:cell interaction. In this study, we present evidence supporting the notion that CD47:SIRPα serves as a cell surface receptor: ligand pair involved in this contact-dependent STAT3 activation and regulation of APC maturation. We show that upon co-culturing APC with various primary and tumor cell lines STAT3 phosphorylation and IL-10 expression are induced, and such regulation could be suppressed by specific CD47 siRNAs and shRNAs. Significantly, >50% reduction in CD47 expression abolished the contact-dependent inhibition of T cell activation. Furthermore, co-immunoprecipitation experiments revealed a physical association between SIRPα and STAT3. Thus, we suggest that in addition to signaling through the ITIM-SHP-1 complex that transmit an anti-phagocytotic, CD47:SIRPα also triggers STAT3 signaling that is linked to an immature APC phenotype and peripheral tolerance under steady state and pathological conditions.

  4. A Neoglycoconjugate Containing the Human Milk Sugar LNFPIII Drives Anti-Inflammatory Activation of Antigen Presenting Cells in a CD14 Dependent Pathway.

    Directory of Open Access Journals (Sweden)

    Smanla Tundup

    Full Text Available The milk pentasaccharide LNFPIII has therapeutic action for metabolic and autoimmune diseases and prolongs transplant survival in mice when presented as a neoglycoconjugate. Within LNFPIII is the Lewisx trisaccharide, expressed by many helminth parasites. In humans, LNFPIII is found in human milk and also known as stage-specific embryonic antigen-1. LNFPIII-NGC drives alternative activation of macrophages and dendritic cells via NFκB activation in a TLR4 dependent mechanism. However, the connection between LNFPIII-NGC activation of APCs, TLR4 signaling and subsequent MAP kinase signaling leading to anti-inflammatory activation of APCs remains unknown. In this study we determined that the innate receptor CD14 was essential for LNFPIII-NGC induction of both ERK and NFkB activation in APCs. Induction of ERK activation by LNFPIII-NGC was completely dependent on CD14/TLR4-Ras-Raf1/TPL2-MEK axis in bone marrow derived dendritic cells (BMDCs. In addition, LNFPIII-NGC preferentially induced the production of Th2 "favoring" chemokines CCL22 and matrix metalloprotease protein-9 in a CD14 dependent manner in BMDCs. In contrast, LNFPIII-NGC induces significantly lower levels of Th1 "favoring" chemokines, MIP1α, MIP1β and MIP-2 compared to levels in LPS stimulated cells. Interestingly, NGC of the identical human milk sugar LNnT, minus the alpha 1-3 linked fucose, failed to activate APCs via TLR4/MD2/CD14 receptor complex, suggesting that the alpha 1-3 linked fucose in LNFPIII and not on LNnT, is required for this process. Using specific chemical inhibitors of the MAPK pathway, we found that LNFPIII-NGC induction of CCL22, MMP9 and IL-10 production was dependent on ERK activation. Over all, this study suggests that LNFPIII-NGC utilizes CD14/TLR4-MAPK (ERK axis in modulating APC activation to produce anti-inflammatory chemokines and cytokines in a manner distinct from that seen for the pro-inflammatory PAMP LPS. These pathways may explain the in vivo

  5. The spacing between adjacent binding sites in the family of repeats affects the functions of Epstein–Barr nuclear antigen 1 in transcription activation and stable plasmid maintenance

    Science.gov (United States)

    Hebner, Christy; Lasanen, Julie; Battle, Scott; Aiyar, Ashok

    2010-01-01

    Epstein–Barr virus (EBV) and the closely related Herpesvirus papio (HVP) are stably replicated as episomes in proliferating latently infected cells. Maintenance and partitioning of these viral plasmids requires a viral sequence in cis, termed the family of repeats (FR), that is bound by a viral protein, Epstein–Barr nuclear antigen 1 (EBNA1). Upon binding FR, EBNA1 maintains viral genomes in proliferating cells and activates transcription from viral promoters required for immortalization. FR from either virus encodes multiple binding sites for the viral maintenance protein, EBNA1, with the FR from the prototypic B95-8 strain of EBV containing 20 binding sites, and FR from HVP containing 8 binding sites. In addition to differences in the number of EBNA1-binding sites, adjacent binding sites in the EBV FR are typically separated by 14 base pairs (bp), but are separated by 10 bp in HVP. We tested whether the number of binding sites, as well as the distance between adjacent binding sites, affects the function of EBNA1 in transcription activation or plasmid maintenance. Our results indicate that EBNA1 activates transcription more efficiently when adjacent binding sites are separated by 10 bp, the spacing observed in HVP. In contrast, using two separate assays, we demonstrate that plasmid maintenance is greatly augmented when adjacent EBNA1-binding sites are separated by 14 bp, and therefore, presumably lie on the same face of the DNA double helix. These results provide indication that the functions of EBNA1 in transcription activation and plasmid maintenance are separable. PMID:12842617

  6. 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

  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. Lung Neutrophils Facilitate Activation of Naïve Antigen Specific CD4+ T Cells During Mycobacterium tuberculosis Infection1

    Science.gov (United States)

    Blomgran, Robert; Ernst, Joel D.

    2012-01-01

    Initiation of the adaptive immune response to Mycobacterium tuberculosis occurs in the lung-draining mediastinal lymph node, and requires transport of M. tuberculosis by migratory dendritic cells (DCs) to the local lymph node. The previously-published observations that: 1) neutrophils are a transiently prominent population of M. tuberculosis-infected cells in the lungs early in infection; and 2) that the peak of infected neutrophils immediately precedes the peak of infected DCs in the lungs, prompted us to characterize the role of neutrophils in the initiation of adaptive immune responses to M. tuberculosis. We found that, although depletion of neutrophils in vivo increased the frequency of M. tuberculosis infected DCs in the lungs, it decreased trafficking of DCs to the mediastinal lymph node. This resulted in delayed activation (CD69 expression) and proliferation of naïve M. tuberculosis Ag85B-specific CD4 T cells in the mediastinal lymph node. To further characterize the role for neutrophils in DC-migration we used a Transwell chemotaxis system and found that DCs that were directly infected by M. tuberculosis migrated poorly in response to CCL19, an agonist for the chemokine receptor CCR7. In contrast, DCs that had acquired M. tuberculosis through uptake of infected neutrophils exhibited unimpaired migration. These results reveal a mechanism wherein neutrophils promote adaptive immune responses to M. tuberculosis by delivering M. tuberculosis to DCs in a form that make DCs more effective initiators of naïve CD4 T cell activation. These observations provide insight into a mechanism for neutrophils to facilitate initiation of adaptive immune responses in tuberculosis. PMID:21555529

  9. Understanding the impact of ErbB activating events and signal transduction on antigen processing and presentation: MHC expression as a model

    Directory of Open Access Journals (Sweden)

    Anna E. Kersh

    2016-09-01

    Full Text Available Advances in molecular pathology have changed the landscape of oncology. The ability to interrogate tissue samples for oncogene amplification, driver mutations, and other molecular alterations provides clinicians with an enormous level of detail about their patient’s cancer. In some cases, this information informs treatment decisions, especially those related to targeted anti-cancer therapies. However, in terms of immune-based therapies, it is less clear how to use such information. Likewise, despite studies demonstrating the pivotal role of neoantigens in predicting responsiveness to immune checkpoint blockade, it is not known if the expression of neoantigens impacts the response to targeted therapies despite a growing recognition of their diverse effects on immunity. To realize the promise of ‘personalized medicine’, it will be important to develop a more integrated understanding of the relationships between oncogenic events and processes governing anti-tumor immunity. One area of investigation to explore such relationships centers on defining how ErbB/HER activation and signal transduction influences antigen processing and presentation.

  10. Antigenic and adjuvant activities of branched aliphatic oligoester (M-DL-LA) microspheres with incorporated bovine rotavirus.

    Science.gov (United States)

    Pokorová, D; Reschová, S; Franz, J; Hampl, J; Dittrich, M

    2002-01-01

    Branched aliphatic oligoester microspheres (msp) with incorporated rotavirus were used to induce the production of systemic and mucosal antibodies in mice. The msp with a mean diameter of 7.4 microm were prepared by the w/o/w technique. The mice were immunized intraperitoneally or orally. High ELISA titres of systemic and local IgG and IgA antibodies were indicative of rotavirus incorporation and of the adjuvant activity of msp. Oral immunization with a split dose administered on three consecutive days, resulted in the production of systemic IgG and IgA antibodies, but failed to induce the production of mucosal antibodies even if the immunization dose was increased threefold. Specific antibodies were detectable in faeces of orally immunized mice only after another triple administration of the same dose in the fourth week of the experiment. Reactions of blood serum IgG with the structural viral proteins VP4, VP6, and VP7 were demonstrated by western blotting. Both systemic, and faecal IgA antibodies were specific for the VP6 protein and the dimeric form of the glycoprotein VP4.

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

    Directory of Open Access Journals (Sweden)

    Anna Pagotto

    Full Text Available 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.

  12. 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.

  13. Intracellular trafficking of bio-nanocapsule-liposome complex: Identification of fusogenic activity in the pre-S1 region of hepatitis B virus surface antigen L protein.

    Science.gov (United States)

    Somiya, Masaharu; Sasaki, Yasuo; Matsuzaki, Takashi; Liu, Qiushi; Iijima, Masumi; Yoshimoto, Nobuo; Niimi, Tomoaki; Maturana, Andrés Daniel; Kuroda, Shun'ichi

    2015-08-28

    Bio-nanocapsules (BNCs) are a hollow nanoparticle consisting of about 100-nm liposome (LP) embedding about 110 molecules of hepatitis B virus (HBV) surface antigen (HBsAg) L protein as a transmembrane protein. Owing to the human hepatocyte-recognizing domains on the N-terminal region (pre-S1 region), BNCs have recently been shown to attach and enter into human hepatic cells using the early infection mechanism of HBV. Since BNCs could form a complex with an LP containing various drugs and genes, BNC-LP complexes have been used as a human hepatic cell-specific drug and gene-delivery system in vitro and in vivo. However, the role of BNCs in cell entry and intracellular trafficking of payloads in BNC-LP complexes has not been fully elucidated. In this study, we demonstrate that low pH-dependent fusogenic activity resides in the N-terminal part of pre-S1 region (NPLGFFPDHQLDPAFG), of which the first FF residues are essential for the activity, and which facilitates membrane fusion between LPs in vitro. Moreover, BNC-LP complexes can bind human hepatic cells specifically, enter into the cells via clathrin-mediated endocytosis, and release their payloads mostly into the cytoplasm. Taken together, the BNC portion of BNC-LP complexes can induce membrane fusion between LPs and endosomal membranes under low pH conditions, and thereby facilitate the endosomal escape of payloads. Furthermore, the fusogenic domain of the pre-S1 region of HBsAg L protein may play a pivotal role in the intracellular trafficking of not only BNC-LP complexes but also of HBV. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Enzymatic characterization, antigenic cross-reactivity and neutralization of dermonecrotic activity of five Loxosceles spider venoms of medical importance in the Americas.

    Science.gov (United States)

    Barbaro, Katia Cristina; Knysak, Irene; Martins, Rosana; Hogan, Christopher; Winkel, Ken

    2005-03-15

    Loxosceles spiders have a wide distribution in the temperate and tropical regions of the world. Loxoscelism is characterized by necrotic skin ulceration at the bite site and, less commonly, a systemic illness that may be fatal. The purpose of this study was to characterize and compare aspects of the major medically important Loxosceles spider venoms in a standardized manner, particularly considering their neutralization by two Brazilian antivenoms. By SDS-PAGE (12% acrylamide), Loxosceles deserta, Loxosceles gaucho, Loxosceles intermedia, Loxosceles laeta and Loxosceles reclusa venoms had similar electrophoretic profiles, with the major protein bands of 32-35 kDa. All venoms exhibited gelatinolytic, caseinolytic and fibrinogenolytic activities in vitro with a large array of proteases, mainly between 18.1 and 31.8 kDa. Most of these enzymes were metalloproteases as this activity was abolished by 1,10-phenanthroline. Hyaluronidase activity was detected in a protein band of approximately 44 kDa in all venoms. Sphingomyelinase activity was demonstrated in all five venoms. Antigenic cross-reactivity, by Western blotting, was also observed among all venoms studied using commercial equine antivenoms produced in Brazil (Institute Butantan and CPPI). These antivenoms recognized mainly components between 25 and 40 kDa in all venoms with several minor components of >89 kDa. Strong cross-reactivity was also seen among all venoms through the ELISA technique (titre range: 64,000-512,000). All venoms (5 microg doses) induced a similar local reaction when injected intradermally into the flank of rabbits, demonstrating dermonecrosis, hemorrhage, vasoconstriction, edema, and erythema. However, no reaction was observed when each venom was pre-incubated (1 h, 37 degrees C) with Brazilian commercial sera prior to injection. The antivenoms also abolished the sphingomyelinase activity in vitro, suggesting the venoms of the major medically important Loxosceles spider species have

  15. Temporal ordering of caspase activation and substrate cleavage during antigen receptor-triggered apoptosis in Ramos-Burkitt lymphoma B cells.

    Science.gov (United States)

    An, Sungkwan; Park, In-Chul; Rhee, Chang Hun; Hong, Seok-Il; Knox, Kirstine

    2003-08-01

    We demonstrate here that selective activation of endogenous members of the caspase family and cleavage of substrates responsible for the maintenance of nuclear functional and structural integrity are major effectors of antigen receptor (AgR)- and ionomycin-triggered apoptosis in Ramos-Burkitt lymphoma (Ramos-BL) B cells. Ramos-BL B cells express significant proenzyme levels of caspase-2, -3, -7 and -8, low levels of caspase-6 and are caspase-1-negative. However, while anti-IgM and ionomycin trigger for significant activation of caspase-3, -7 and -8 at 12-16 h and at 4 h post-stimulation respectively, both anti-IgM and ionomycin fail to activate caspase-2 indicating that AgR- and ionomycin-triggered Ramos-BL B cell apoptosis is mediated by the selective activation of, at least, caspase-3, -7 and -8. Anti-IgM triggers for cleavage of the resident nuclear proteins poly(ADP-ribose) polymerase (PARP) at 8 h, lamins B1 and B2 from 12 to 16 h; likewise, ionomycin triggers for degradation of PARP at 2 h, lamins B1 and B2 at 4 h. Signal transduction through CD40 rescues Ramos-BL B cells from AgR- and ionomycin-triggered apoptosis at a very early stage of the apoptotic process by inhibiting both the early cleavage of PARP as well as the activation of caspase-3, -7 and -8 and cleavage of lamin B1; CD40-mediated rescue occurs upstream of CD40-induced expression of Bcl-2 and increased expression of Bcl-xL. In such cellular populations subject to regulation through apoptosis, dysregulation of the apoptotic mechanisms can have devastating consequences by contributing to the pathogenesis of malignancy as well as to lymphoproliferative and autoantibody disorders. An understanding of the role played by caspases in the execution of apoptosis may provide insight into the pathogenesis of these disease states and thereby provide targets for novel therapeutic strategy.

  16. Adaptive Immune Response to Model Antigens Is Impaired in Murine Leukocyte-Adhesion Deficiency-1 Revealing Elevated Activation Thresholds In Vivo

    Directory of Open Access Journals (Sweden)

    Thorsten Peters

    2012-01-01

    Full Text Available Absence of β2 integrins (CD11/CD18 leads to leukocyte-adhesion deficiency-1 (LAD1, a rare primary immunodeficiency syndrome. Although extensive in vitro work has established an essential function of β2 integrins in adhesive and signaling properties for cells of the innate and adaptive immune system, their respective participation in an altered adaptive immunity in LAD1 patients are complex and only partly understood in vivo. Therefore, we investigated adaptive immune responses towards different T-dependent antigens in a murine LAD1 model of β2 integrin-deficiency (CD18−/−. CD18−/− mice generated only weak IgG responses after immunization with tetanus toxoid (TT. In contrast, robust hapten- and protein-specific immune responses were observed after immunization with highly haptenated antigens such as (4-hydroxy-3-nitrophenyl21 acetyl chicken γ globulin (NP21-CG, even though regularly structured germinal centers with specificity for the defined antigens/haptens in CD18−/− mice remained absent. However, a decrease in the hapten/protein ratio lowered the efficacy of immune responses in CD18−/− mice, whereas a mere reduction of the antigen dose was less crucial. Importantly, haptenation of TT with NP (NP-TT efficiently restored a robust IgG response also to TT. Our findings may stimulate further studies on a modification of vaccination strategies using highly haptenated antigens in individuals suffering from LAD1.

  17. 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.

  18. Vav links the T cell antigen receptor to the actin cytoskeleton and T cell activation independently of intrinsic Guanine nucleotide exchange activity.

    Directory of Open Access Journals (Sweden)

    Ana V Miletic

    2009-08-01

    Full Text Available T cell receptor (TCR engagement leads to formation of signaling microclusters and induction of rapid and dynamic changes in the actin cytoskeleton, although the exact mechanism by which the TCR initiates actin polymerization is incompletely understood. The Vav family of guanine nucleotide exchange factors (GEF has been implicated in generation of TCR signals and immune synapse formation, however, it is currently not known if Vav's GEF activity is required in T cell activation by the TCR in general, and in actin polymerization downstream of the TCR in particular.Here, we report that Vav1 assembles into signaling microclusters at TCR contact sites and is critical for TCR-initiated actin polymerization. Surprisingly, Vav1 functions in TCR signaling and Ca(++ mobilization via a mechanism that does not appear to strictly depend on the intrinsic GEF activity.We propose here a model in which Vav functions primarily as a tyrosine phosphorylated linker-protein for TCR activation of T cells. Our results indicate that, contrary to expectations based on previously published studies including from our own laboratory, pharmacological inhibition of Vav1's intrinsic GEF activity may not be an effective strategy for T cell-directed immunosuppressive therapy.

  19. 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...

  20. Non-major histocompatibility complex-restricted cytotoxic activity of blood mononuclear cells stimulated with secreted mycobacterial proteins and other mycobacterial antigens

    DEFF Research Database (Denmark)

    Ravn, P; Pedersen, B K

    1994-01-01

    with tuberculin purified protein derivative, Mycobacterium bovis bacillus Calmette-Guérin (BCG), short- and long-term culture filtrates of virulent Mycobacterium tuberculosis H37Rv, and 30-31-kDa secreted mycobacterial protein. These antigens also induced proliferation and production of gamma interferon. The CD4...

  1. The expression and functional activity of membrane-bound human leukocyte antigen-G1 are influenced by the 3'-untranslated region

    DEFF Research Database (Denmark)

    Svendsen, Signe Goul; Hantash, Basil M; Zhao, Longmei

    2013-01-01

    Human Leukocyte Antigen (HLA)-G is an immunosuppressive molecule acting on both the innate and adaptive immune system. A 14 bp insertion/deletion polymorphism (rs66554220) in the 3'-untranslated region (3'UTR) of the HLA-G gene has been associated with a number of diseases, pregnancy complication...

  2. The Fos-Related Antigen 1–JUNB/Activator Protein 1 Transcription Complex, a Downstream Target of Signal Transducer and Activator of Transcription 3, Induces T Helper 17 Differentiation and Promotes Experimental Autoimmune Arthritis

    Directory of Open Access Journals (Sweden)

    Young-Mee Moon

    2017-12-01

    Full Text Available Dysfunction of T helper 17 (Th17 cells leads to chronic inflammatory disorders. Signal transducer and activator of transcription 3 (STAT3 orchestrates the expression of proinflammatory cytokines and pathogenic cell differentiation from interleukin (IL-17-producing Th17 cells. However, the pathways mediated by STAT3 signaling are not fully understood. Here, we observed that Fos-related antigen 1 (FRA1 and JUNB are directly involved in STAT3 binding to sites in the promoters of Fosl1 and Junb. Promoter binding increased expression of IL-17 and the development of Th17 cells. Overexpression of Fra1 and Junb in mice resulted in susceptibility to collagen-induced arthritis and an increase in Th17 cell numbers and inflammatory cytokine production. In patients with rheumatoid arthritis, FRA1 and JUNB were colocalized with STAT3 in the inflamed synovium. These observations suggest that FRA1 and JUNB are associated closely with STAT3 activation, and that this activation leads to Th17 cell differentiation in autoimmune diseases and inflammation.

  3. Tolerance to noninherited maternal antigens, reproductive microchimerism and regulatory T cell memory: 60 years after ‘Evidence for actively acquired tolerance to Rh antigens’

    Science.gov (United States)

    Kinder, Jeremy M.; Jiang, Tony T.; Ertelt, James M.; Xin, Lijun; Strong, Beverly S.; Shaaban, Aimen F.; Way, Sing Sing

    2015-01-01

    ABSTRACT Compulsory exposure to genetically foreign maternal tissue imprints in offspring sustained tolerance to noninherited maternal antigens (NIMA). Immunological tolerance to NIMA was first described by Dr. Ray D. Owen for women genetically negative for erythrocyte rhesus (Rh) antigen with reduced sensitization from developmental Rh exposure by their mothers. Extending this analysis to HLA haplotypes has uncovered the exciting potential for therapeutically exploiting NIMA-specific tolerance naturally engrained in mammalian reproduction for improved clinical outcomes after allogeneic transplantation. Herein, we summarize emerging scientific concepts stemming from tolerance to NIMA that includes postnatal maintenance of microchimeric maternal origin cells in offspring, expanded accumulation of immune suppressive regulatory T cells with NIMA-specificity, along with teleological benefits and immunological consequences of NIMA-specific tolerance conserved across mammalian species. PMID:26517600

  4. T-antigen binding lectin with antibacterial activity from marine invertebrate, sea cucumber (Holothuria scabra): Possible involvement in differential recognition of bacteria

    Digital Repository Service at National Institute of Oceanography (India)

    Gowda, N.M.; Goswami, U.; Khan, M.I.

    unchallenged animals served as control. After the 8th day, the same sets of animals were rechal- lenged as before to determine the presence of any immune memory. 2.3. Estimation of residual bacterial load Prior to processing, an aliquot was removed from... a G protein- mediated signaling pathway (Ozaki et al., 2005). Immune system in vertebrates is characterized by the unique property of memory, whereby a second antigen challenge results in immediate response. In order to examine the involvement...

  5. Cancer vaccine--Antigenics.

    Science.gov (United States)

    2002-01-01

    Antigenics is developing a therapeutic cancer vaccine based on heat-shock proteins (HSPs). The vaccine [HSPPC-96, Oncophage] is in a pivotal phase III clinical trial for renal cancer at 80 clinical sites worldwide. The trial is enrolling at least 500 patients who are randomised to receive surgical removal of the primary tumour followed by out-patient treatment with Oncophage((R)) or surgery only. This study was initiated on the basis of results from a pilot phase I/II study and preliminary results from a phase II study in patients with renal cell cancer. In October 2001, Oncophage was designated as a fast-track product by the Food and Drug Administration in the US for the treatment of renal cell carcinoma. Oncophage is in phase I/II trials in Italy for colorectal cancer (30 patients) and melanoma. The trials in Italy are being conducted at the Istituto dei Tumouri, Milan (in association with Sigma-Tau). Preliminary data from the phase II trial for melanoma was presented at the AACR-NCI-EORTC International Conference in Florida, USA, in October 2001. Oncophage is also in a phase I/II (42 patients) and a phase II trial (84 patients) in the US for renal cell cancer, a phase II trial in the US for non-Hodgkin's lymphoma (35 patients), a phase II trial in the US for sarcoma (20-35 patients), a phase I/II trial in the US for melanoma (36 patients), and phase I/II trials in Germany for gastric (30 patients) and pancreatic cancers. A pilot phase I trial in patients with pancreatic cancer began in the US in 1997 with 5 patients enrolled. In November 2000, Antigenics announced that this trial had been expanded to a phase I/II study which would now include survival as an endpoint and would enroll 5 additional patients. The US trials are being performed at Memorial Sloan-Kettering Cancer Center and the M.D. Anderson Cancer Center. The trials in Germany are being carried out at Johannes Gutenberg-University Hospital, Mainz. Oncophage is an autologous vaccine consisting of

  6. Interpretation of sequential measurements of cancer antigen 125 (CA 125), carcinoembryonic antigen (CEA), and tissue polypeptide antigen (TPA) based on analytical imprecision and biological variation in the monitoring of ovarian cancer

    DEFF Research Database (Denmark)

    Tuxen, Malgorzata K.; Sölétormos, G; Petersen, P H

    2001-01-01

    The main objective with cancer antigen 125 (CA 125), carcinoembryonic antigen (CEA), and tissue polypeptide antigen (TPA) monitoring of ovarian cancer patients is to detect an early change of disease activity with high reliability. We hypothesized that a monitoring scheme for ovarian cancer patie...

  7. Synthesis, Antigenicity Against Human Sera and Structure-Activity Relationships of Carbohydrate Moieties from Toxocara larvae and Their Analogues

    Directory of Open Access Journals (Sweden)

    Takashi Tsuchiya

    2012-07-01

    Full Text Available Stereocontrolled syntheses of biotin-labeled oligosaccharide portions containing the Galβ1-3GalNAc core of the TES-glycoprotein antigen obtained from larvae of the parasite Toxocara and their analogues have been accomplished. Trisaccharides Fuc2Meα1-2Gal4Meβ1-3GalNAcα1-OR (A, Fucα1-2Gal4Meβ1-3GalNAcα1-OR (B, Fuc2Meα1-2Galβ1-3GalNAcα1-OR (C, Fucα1-2Galβ1-3GalNAcα1-OR (D and a disaccharide Fuc2Meα1-2Gal4Meβ1-OR (E (R = biotinylated probe were synthesized by block synthesis using 5-(methoxycarbonylpentyl-2,3,4,6-tetra-O-acetyl-β-D-galactopyranosyl-(1®3-2-azide-4-O-benzyl-2-deoxy-α-D-galactopyranoside as a common glycosyl acceptor. We examined the antigenicity of these five oligosaccharides by enzyme linked immunosorbent assay (ELISA. Our results demonstrate that the O-methyl groups in these oligosaccharides are important for their antigenicity and the biotinylated oligosaccharides A, B, C and E have high serodiagnostic potential to detect infections caused by Toxocara larvae.

  8. Epstein-Barr virus (EBV) glycoprotein gp350 expressed on transfected cells resistant to natural killer cell activity serves as a target antigen for EBV-specific antibody-dependent cellular cytotoxicity.

    Science.gov (United States)

    Khyatti, M; Patel, P C; Stefanescu, I; Menezes, J

    1991-02-01

    Cell surface-associated viral glycoproteins are thought to play a major role as target antigens in cellular cytotoxicity and antiviral immunosurveillance. One such glycoprotein is the Epstein-Barr virus (EBV)-encoded glycoprotein 350 (gp350), which is expressed on both virion envelope and EBV producer cells and carries the virus attachment protein moiety. Although it is known that some antibodies to gp350 can neutralize the virus, the role of this glycoprotein in EBV-specific cellular cytotoxicity is not yet clear. We describe here a study in which we successfully used a new approach to demonstrate that gp350 is a target antigen for EBV-specific antibody-dependent cellular cytotoxicity (ADCC). Transfection of gp350-negative cells resistant to natural killer (NK) cell activity (i.e., Raji) with a recombinant vector (pZIP-MA) containing the gene encoding the EBV-gp350 and the neomycin resistance gene enabled us to isolate cell clones with a stable and strong expression of gp350 on their surface membranes. ADCC determined by using two clones clearly demonstrated that gp350 is the target of the EBV ADCC. Interestingly, this ADCC was comparable to that obtained against the EBV-superinfected (coated) Raji cell expressing the same percentage of gp350 positivity as the two clones. No cytotoxic activity was detected against either nontransfected (gp350-negative) Raji cells or cells transfected with the vector [pZIP-neo-SV(X)1] lacking the gp350 gene. In addition to demonstrating that gp350 is a target molecule for EBV-specific ADCC, our approach in using NK-resistant transfectants provides a lead for probing the role of cell surface-associated viral antigens in specific cellular killing and immunosurveillance.

  9. Androgen Receptor Exon 1 Mutation Causes Androgen Insensitivity by Creating Phosphorylation Site and Inhibiting Melanoma Antigen-A11 Activation of NH2- and Carboxyl-terminal Interaction-dependent Transactivation*

    Science.gov (United States)

    Lagarde, William H.; Blackwelder, Amanda J.; Minges, John T.; Hnat, Andrew T.; French, Frank S.; Wilson, Elizabeth M.

    2012-01-01

    Naturally occurring germ line mutations in the X-linked human androgen receptor (AR) gene cause incomplete masculinization of the external genitalia by disrupting AR function in males with androgen insensitivity syndrome. Almost all AR missense mutations that cause androgen insensitivity syndrome are located in the highly structured DNA and ligand binding domains. In this report we investigate the functional defect associated with an AR exon 1 missense mutation, R405S, that caused partial androgen insensitivity. The 46,XX heterozygous maternal carrier had a wild-type Arg-405 CGC allele but transmitted an AGC mutant allele coding for Ser-405. At birth, the 46,XY proband had a bifid scrotum, hypospadias, and micropenis consistent with clinical stage 3 partial androgen insensitivity. Androgen-dependent transcriptional activity of AR-R405S expressed in CV1 cells was less than wild-type AR and refractory in androgen-dependent AR NH2- and carboxyl interaction transcription assays that depend on the coregulator effects of melanoma antigen-A11. This mutation created a Ser-405 phosphorylation site evident by the gel migration of an AR-R405S NH2-terminal fragment as a double band that converted to the wild-type single band after treatment with λ-phosphatase. Detrimental effects of the R405S mutation were related to the proximity of the AR WXXLF motif 433WHTLF437 required for melanoma antigen-A11 and p300 to stimulate transcriptional activity associated with the AR NH2- and carboxyl-terminal interaction. We conclude that the coregulator effects of melanoma antigen-A11 on the AR NH2- and carboxyl-terminal interaction amplify the androgen-dependent transcriptional response to p300 required for normal human male sex development in utero. PMID:22334658

  10. Androgen receptor exon 1 mutation causes androgen insensitivity by creating phosphorylation site and inhibiting melanoma antigen-A11 activation of NH2- and carboxyl-terminal interaction-dependent transactivation.

    Science.gov (United States)

    Lagarde, William H; Blackwelder, Amanda J; Minges, John T; Hnat, Andrew T; French, Frank S; Wilson, Elizabeth M

    2012-03-30

    Naturally occurring germ line mutations in the X-linked human androgen receptor (AR) gene cause incomplete masculinization of the external genitalia by disrupting AR function in males with androgen insensitivity syndrome. Almost all AR missense mutations that cause androgen insensitivity syndrome are located in the highly structured DNA and ligand binding domains. In this report we investigate the functional defect associated with an AR exon 1 missense mutation, R405S, that caused partial androgen insensitivity. The 46,XX heterozygous maternal carrier had a wild-type Arg-405 CGC allele but transmitted an AGC mutant allele coding for Ser-405. At birth, the 46,XY proband had a bifid scrotum, hypospadias, and micropenis consistent with clinical stage 3 partial androgen insensitivity. Androgen-dependent transcriptional activity of AR-R405S expressed in CV1 cells was less than wild-type AR and refractory in androgen-dependent AR NH(2)- and carboxyl interaction transcription assays that depend on the coregulator effects of melanoma antigen-A11. This mutation created a Ser-405 phosphorylation site evident by the gel migration of an AR-R405S NH(2)-terminal fragment as a double band that converted to the wild-type single band after treatment with λ-phosphatase. Detrimental effects of the R405S mutation were related to the proximity of the AR WXXLF motif (433)WHTLF(437) required for melanoma antigen-A11 and p300 to stimulate transcriptional activity associated with the AR NH(2)- and carboxyl-terminal interaction. We conclude that the coregulator effects of melanoma antigen-A11 on the AR NH(2)- and carboxyl-terminal interaction amplify the androgen-dependent transcriptional response to p300 required for normal human male sex development in utero.

  11. 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

  12. Antigen-targeting strategies using single-domain antibody fragments

    NARCIS (Netherlands)

    Duarte, Joao Nuno Silva

    2017-01-01

    Antibodies display high selectivity and affinity and have been the preferred platform for antigen targeting. Despite the development of antigen-delivery systems that enable T cell activation, targeting approaches that enhance antibody responses need improvement. This need specially applies to poorly

  13. Artificial antigen-presenting cells expressing AFP(158-166) peptide and interleukin-15 activate AFP-specific cytotoxic T lymphocytes.

    Science.gov (United States)

    Sun, Longhao; Guo, Hao; Jiang, Ruoyu; Lu, Li; Liu, Tong; Zhang, Zhixiang; He, Xianghui

    2016-04-05

    Professional antigen-presenting cells (APCs) are potent generators of tumor antigen-specific cytotoxic T lymphocytes (CTLs) for adoptive immunotherapy; however, generation of APCs is cumbersome, expensive, and subject to the tumor microenvironment. Artificial APCs (aAPCs) have been developed as a cost-effective alternative to APCs. We developed a cellular aAPC that efficiently generated alpha-fetoprotein (AFP)-specific CTLs. We genetically modified the human B cell lymphoma cell line BJAB with a lentiviral vector to establish an aAPC called BA15. The expression of AFP(158-166)-HLA-A*02:01 complex, CD80, CD86, and interleukin (IL)-15 in BA15 cells was assessed. The efficiency of BA15 at generating AFP-specific CTLs and the specific cytotoxicity of CTLs against AFP+ cells were also determined. BA15 cells expressed high levels of AFP(158-166) peptide, HLA-A2, CD80, CD86, and IL-15. BA15 cells also exhibited higher efficiency in generating AFP-specific CTLs than did dendritic cells. These CTLs had greater cytotoxicity against AFP+ hepatocellular carcinoma cells than did CTLs obtained from dendritic cells in vitro and in vivo. Our novel aAPC system could provide a robust platform for the generation of functional AFP-specific CTLs for adoptive immunotherapy of hepatocellular carcinoma.

  14. L1 Cell Adhesion Molecule-Specific Chimeric Antigen Receptor-Redirected Human T Cells Exhibit Specific and Efficient Antitumor Activity against Human Ovarian Cancer in Mice.

    Science.gov (United States)

    Hong, Hao; Brown, Christine E; Ostberg, Julie R; Priceman, Saul J; Chang, Wen-Chung; Weng, Lihong; Lin, Paul; Wakabayashi, Mark T; Jensen, Michael C; Forman, Stephen J

    2016-01-01

    New therapeutic modalities are needed for ovarian cancer, the most lethal gynecologic malignancy. Recent clinical trials have demonstrated the impressive therapeutic potential of adoptive therapy using chimeric antigen receptor (CAR)-redirected T cells to target hematological cancers, and emerging studies suggest a similar impact may be achieved for solid cancers. We sought determine whether genetically-modified T cells targeting the CE7-epitope of L1-CAM, a cell adhesion molecule aberrantly expressed in several cancers, have promise as an immunotherapy for ovarian cancer, first demonstrating that L1-CAM was highly over-expressed on a panel of ovarian cancer cell lines, primary ovarian tumor tissue specimens, and ascites-derived primary cancer cells. Human central memory derived T cells (TCM) were then genetically modified to express an anti-L1-CAM CAR (CE7R), which directed effector function upon tumor antigen stimulation as assessed by in vitro cytokine secretion and cytotoxicity assays. We also found that CE7R+ T cells were able to target primary ovarian cancer cells. Intraperitoneal (i.p.) administration of CE7R+ TCM induced a significant regression of i.p. established SK-OV-3 xenograft tumors in mice, inhibited ascites formation, and conferred a significant survival advantage compared with control-treated animals. Taken together, these studies indicate that adoptive transfer of L1-CAM-specific CE7R+ T cells may offer a novel and effective immunotherapy strategy for advanced ovarian cancer.

  15. Oncogenic cancer/testis antigens

    DEFF Research Database (Denmark)

    Gjerstorff, Morten F; Andersen, Mads H; Ditzel, Henrik J

    2015-01-01

    immunology and immune escape suggests that targeting oncogenic antigens may be beneficial, meaning that identification of cancer/testis antigens with oncogenic properties is of high priority. Recent work from our lab and others provide evidence that many cancer/testis antigens, in fact, have oncogenic...... functions, including support of growth, survival and metastasis. This novel insight into the function of cancer/testis antigens has the potential to deliver more effective cancer vaccines. Moreover, immune targeting of oncogenic cancer/testis antigens in combination with conventional cytotoxic therapies...

  16. Deteksi Antigen pada Kriptokokosis

    Directory of Open Access Journals (Sweden)

    Robiatul Adawiyah

    2014-12-01

    Full Text Available AbstrakKriptokokosis merupakan infeksi sistemik yang disebabkan Cryptococcus sp. Predileksi jamur tersebut adalah susunan saraf pusat dan selaput otak. Terdapat 5 spesies Cryptococcus sp. yang menyebabkan penyakit pada manusia; yang paling banyak adalah Cr. neoformans dan Cr. gattii. Diagnosis kriptokokosis ditegakkan berdasarkan gejala klinis, pemeriksaan laboratoris serta radiologis. Pemeriksaan laboratoris dilakukan dengan identifikasi morfologi, serologi danPCR. Pemeriksaan secara morfologi dengan tinta India positif  bila jumlah sel jamur 10  sel/ml spesimen. Kultur dilakukan di media sabouraud dextrose agar (SDA dan niger sheed agar (NSA, jamur tumbuh setelah 5-7 hari. Deteksi antigen dan antibodi dilakukan pada cairan tubuh dan tidak membutuhkan waktu lama. Deteksi antibodi Cr.neoformans memiliki kelemahan yaitu tidak menunjukkan hasil positif pada infeksi akut, IgA masih positif setelah 1-2 tahun fase penyembuhan, IgG dapat persisten, pada individu imunokompromis menunjukkan hasil yang sangat kompleks dan dalam menentukan diagnosis sering tidak konsisten. Polisakarida adalah komponen paling berperan dalam virulensi Cr. neoformans. Komponen polisakarida terutama glucuronoxylomannan merupakan petanda penting dalam diagnosis kriptokokosis secara serologis. Deteksi antigen Cr. neoformans memiliki kelebihan yaitu menunjukkan hasil positif pada infeksi akut/kronis, sensitivitas dan spesifisitas tinggi, dapat mendeteksi polisakarida hingga 10 ng/ml sehingga dengan kadarantigen yang minimal tetap dapat mendiagnosis kriptokokosis.Kata kunci: Cr. neoformans, glucuronoxylomannan, antigenAbstractCryptococcosis is systemic infection that caused by Cryptococcus sp. Predilection of this fungi is the central nervous system and brain membrane. There are 5 species of Cryptococcus sp. that cause cryptococcosis in human; but the majority are caused by Cr. neoformans and Cr. gattii. The diagnosis of cryptococcosis is made based on clinical symptoms

  17. Human antigen-presenting cells respond differently to gut-derived probiotic bacteria but mediate similar strain-dependent NK and T cell activation

    DEFF Research Database (Denmark)

    Fink, Lisbeth Nielsen; Zeuthen, Louise Hjerrild; Ferlazzo, Guido

    2007-01-01

    , in vitro assessment of the immunomodulatory effects of distinct strains may depend strongly on the cell type used as a model. To select the most appropriate model for screening of beneficial bacteria in human cells, the response to strains of intestinal bacteria of three types of antigen-presenting cells...... (APC) was compared; blood myeloid dendritic cells (DC), monocyte-derived DC and monocytes, and the effector response of natural killer cells and naïve T cells was characterized. Maturation induced by gut-derived bacteria differed between APC, with blood DC and monocytes responding with the production...... of IL-6 and tumour necrosis factor-alpha to bacteria, which elicited mainly IL-10 in monocyte-derived DC. In contrast, comparable IFN-gamma production patterns were found in both natural killer cells and T cells induced by all bacteria-matured APC. An inhibitory effect of certain strains on this IFN...

  18. Comparison of influenza vaccine effectiveness using different methods of case detection: clinician-ordered rapid antigen tests vs. active surveillance and testing with real-time reverse-transcriptase polymerase chain reaction (rRT-PCR).

    Science.gov (United States)

    Coleman, Laura A; Kieke, Burney; Irving, Stephanie; Shay, David K; Vandermause, Mary; Lindstrom, Stephen; Belongia, Edward A

    2011-01-10

    Annual evaluation of influenza vaccine effectiveness (VE) is needed to assess ongoing impact of immunization efforts in the setting of antigenic drift and periodic vaccine reformulation. Optimal methodology for determining VE remains unclear. We compared influenza VE generated from prospective enrollment and rRT-PCR testing (active surveillance group) with VE based on clinician-ordered diagnostic tests (clinical testing group) in a defined population over four seasons. VE was calculated as (1 - adjusted OR) for vaccination in cases vs. test-negative controls. VE based on clinical testing underestimated VE based on active surveillance and testing with rRT-PCR by 5-33% depending on season. Copyright © 2010 Elsevier Ltd. All rights reserved.

  19. Recombined DNA vaccines encoding calreticulin linked to HPV6bE7 enhance immune response and inhibit angiogenic activity in B16 melanoma mouse model expressing HPV 6bE7 antigen.

    Science.gov (United States)

    Zhao, Ke-Jia; Cheng, Hao; Zhu, Ke-Jian; Xu, Yan; Chen, Min-Li; Zhang, Xing; Song, Tao; Ye, Jun; Wang, Qi; Chen, Da-Fang

    2006-07-01

    Calreticulin (CRT) has been reported to have an effect of upregulating MHC class I presentation as well as inhibiting angiogenesis in vitro and in vivo. Combination of dual mechanisms of enhanced immunogenicity of human papillomavirus (HPV) 6bE7 antigen and antiangiogenesis may be introduced in the strategy of vaccines against condyloma acuminatum (CA) resulting from HPV infection. Therefore, we constructed DNA vaccines by employing different lengths of CRT chimerically linked to a model antigen HPV6bE7 and investigated the immunological and antiangiogenic effects of these vaccines in a B16 melanoma model that express HPV6bE7 antigen. Our results showed that vaccination with CRT180/HPV6bE7 or CRT120/HPV6bE7 enhanced the presence of CD8(+) T cells and TCRgammadelta T cells in vivo, increased the specific lysis activity against E7-expressing cells and secretion levels of IL-2 and IFN-gamma by activating T cells in vitro significantly. Moreover, recombined CRT180 or CRT120 with HPV6bE7 vaccines could elicit a more efficient E7-specific immune response than HPV6bE7 alone. The similarity of immunological enhancement of CRT180/HPV6bE7 and CRT120/HPV6bE7 implies that the immunologically active region mainly exist in fragment 1-120 aa. Furthermore, CRT180/HPV6bE7 and CRT180 displayed remarkable superiority over CRT120/HPV6bE7 in vivo angiogenesis assay, suggesting that the antiangiogenic activity of CRT resides in a domain between aa 120 and 180. Vaccination with CRT180/HPV6bE7 generated the best protective effect of delaying tumor formation and reduction of tumor size in tumor growth inhibition experiment among all DNA constructs. Therefore, CRT180/HPV6bE7 vaccine may enhance the immunological response to HPV6bE7 and inhibit angiogenesis. This construct may be useful in preventing HPV-associated dermatosis and may be developed as a promising strategy to control CA.

  20. Antigen pulsed CpG-ODN activated dendritic cells induce host-protective immune response by regulating the T regulatory cell functioning in Leishmania donovani-infected mice: critical role of CXCL10

    Directory of Open Access Journals (Sweden)

    Saikat eMajumder

    2014-06-01

    Full Text Available Visceral leishmaniasis (VL, caused by Leishmania donovani, is a systemic infection of reticulo-endothelial system. There is currently no protective vaccine against VL and chemotherapy is increasingly limited due to appearance of drug resistance to first line drugs such as antimonials and amphotericin B. In the present study, by using a murine model of leishmaniasis we evaluated the function played by soluble leishmanial antigen (SLA pulsed-CpG-ODN stimulated dendritic cells (SLA-CpG-DCs in restricting the intracellular parasitic growth. We establish that a single dose of SLA-CpG-DCs vaccination is sufficient in rendering complete protection against Leishmania donovani infection. In probing the possible mechanism, we observed that SLA-CpG-DCs vaccination results in the significant decrease in Foxp3+GITR+CTLA4+CD4+CD25+ Treg cell population in Leishmania-infected mice. Vaccination with these antigen stimulated dendritic cells results in the decrease in the secretion of TGF-β by these Treg cells by possible regulation of the SMAD signalling. Moreover, we demonstrated that a CXC chemokine, IFN-γ-inducible protein 10 (IP-10, has a direct role in the regulation of CD4+CD25+ Treg cells in SLA-CpG-DCs vaccinated parasitized mice as Treg cells isolated from IP-10 depleted vaccinated mice showed significantly increased TGF-β production and suppressive activity.

  1. MHC class II antigen presentation by B cells in health and disease

    NARCIS (Netherlands)

    Souwer, Yuri

    2009-01-01

    MHC class II antigen presentation by B cells is important to activate CD4+ T cells that stimulate the B cell to produce antibodies. Besides this, disruption of MHC class II antigen presentation could play a role in immune escape by tumor cells. This thesis describes MHC class II antigen presentation

  2. Evolução clínica muito tardia de pacientes com infarto agudo do miocárdio submetidos a angioplastia primária Very late clinical progression of patients with acute myocardial infarction submitted to primary angioplasty

    Directory of Open Access Journals (Sweden)

    Dinaldo Cavalcanti de Oliveira

    2008-04-01

    primary stenting. All the patients were followed up clinically and we assessed the occurrence of deaths, acute myocardial infarction (AMI, cerebral vascular accident (CVA and surgical or percutaneous myocardial revascularization (MR. Kaplan-Meier survival curves were built for the following events: death, deaths/AMI, deaths/AMI/CVA and major cardiovascular events (MCE. RESULTS: In 91.5% of the patients the procedure was successful. During hospital stay, mortality was 3.4%; reinfarction was 0.9%; CVA was 1.8%; and urgent MR was 1.4%. Clinical follow-up varied from 29 to 100 months (mean = 58.7 ± 19.7 months. Death-free survival was estimated at 93.6%; death/AMI-free survival at 89.6%; death-AMI/CVA-free survival at 87.1%; and MCE-free survival at 71.3% CONCLUSION: Primary stenting presented excellent results during hospital stay. Very late clinical follow-up demonstrated that these good initial results have held up.

  3. 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.

  4. Participation of L3T4 in T cell activation in the absence of class II major histocompatibility complex antigens. Inhibition by anti-L3T4 antibodies is a function both of epitope density and mode of presentation of anti-receptor antibody

    DEFF Research Database (Denmark)

    Owens, T; Fazekas de St Groth, B

    1987-01-01

    The recognition of many class II major histocompatibility complex (MHC)-associated antigens by T cells requires the participation of the L3T4 molecule. It has been proposed that this molecule acts to stabilize low affinity binding to antigen in association with MHC and thereby increases the avidity...... of T cell/antigen interactions. By using antibodies against the T cell antigen receptor (TCR) to activate T cells, thereby circumventing the requirement for antigen presenting cells and MHC-associated antigen, we have been able to study the function of L3T4 in the absence of class II MHC. We have used...... two monoclonal antibodies, KJ16-133.18 and F23.1, that recognize a determinant encoded by the T cell receptor V beta 8 gene family. These antibodies were used to select two clones of T cells with surface phenotype Thy-1.2+, L3T4+, Lyt-2-, KJ16-133.18+, F23.1+, IA-, IE-. One of these clones (E9.D4...

  5. Incomplete effector/memory differentiation of antigen-primed CD8+ T cells in gene gun DNA-vaccinated mice

    DEFF Research Database (Denmark)

    Bartholdy, Christina; Stryhn, Anette; Hansen, Nils Jacob Vest

    2003-01-01

    sites. Thus, our DNA vaccine induces a long-lived memory CD8+ T cell population that provides efficient protection against high-dose systemic infection. However, viral replication in solid non-lymphoid organs is not curtailed sufficiently fast to prevent significant virus-induced inflammation. Our......-restricted epitopes of lymphocytic choriomeningitis virus covalently linked to beta2-microglobulin. This vaccine construct primed for a stronger recall response than did a more conventional minigene construct. Despite this, vaccinated mice were only protected against systemic infection whereas protection against...... the consequences of peripheral challenge was limited. Phenotypic analysis revealed that DNA vaccine-primed CD8+ T cells in uninfected mice differed from virus-primed CD8+ T cells particularly regarding expression of very-late antigen (VLA)-4, an adhesion molecule important for targeting T cells to inflammatory...

  6. Antigen antibody interactions

    CERN Document Server

    DeLisi, Charles

    1976-01-01

    1. 1 Organization of the Immune System One of the most important survival mechanisms of vertebrates is their ability to recognize and respond to the onslaught of pathogenic microbes to which they are conti- ously exposed. The collection of host cells and molecules involved in this recognition­ 12 response function constitutes its immune system. In man, it comprises about 10 cells 20 (lymphocytes) and 10 molecules (immunoglobulins). Its ontogenic development is c- strained by the requirement that it be capable of responding to an almost limitless variety of molecular configurations on foreign substances, while simultaneously remaining inert to those on self components. It has thus evolved to discriminate, with exquisite precision, between molecular patterns. The foreign substances which induce a response, called antigens, are typically large molecules such as proteins and polysaccharides. The portions of these with which immunoglobulins interact are called epitopes or determinants. A typical protein epitope m...

  7. Radioimmunoassays of hidden viral antigens

    Energy Technology Data Exchange (ETDEWEB)

    Neurath, A.R. (Lindsley F. Kimbell Research Inst., New York, NY); Strick, N.; Baker, L.; Krugman, S.

    1982-07-01

    Antigens corresponding to infectious agents may be present in biological specimens only in a cryptic form bound to antibodies and, thus, may elude detection. We describe a solid-phase technique for separation of antigens from antibodies. Immune complexes are precipitated from serum by polyethylene glycol, dissociated with NaSCN, and adsorbed onto nitrocellulose or polystyrene supports. Antigens remain topographically separated from antibodies after removal of NaSCN and can be detected with radiolabeled antibodies. Genomes from viruses immobilized on nitrocellulose can be identified by nucleic acid hybridization. Nanogram quantities of sequestered hepatitis B surface and core antigens and picogram amounts of hepatitis B virus DNA were detected. Antibody-bound adenovirus, herpesvirus, and measles virus antigens were discerned by the procedure.

  8. Cancer antigen 125 and prognosis

    DEFF Research Database (Denmark)

    Høgdall, Estrid Vilma Solyom

    2008-01-01

    PURPOSE OF REVIEW: This review addresses recently reported progress in cancer antigen 125 as a prognostic marker in patients with ovarian cancer. RECENT FINDINGS: Serum cancer antigen 125 levels measured preoperatively in both early and late stage ovarian cancer may be of prognostic value. Before...... cancer antigen 125 determination may be implemented into clinical practice, cut-off levels must be evaluated and internationally defined. Studies examining serum cancer antigen 125 levels after surgery but before, during, or after treatment confirmed that changes in serum levels are of prognostic value....... Furthermore, recent studies have shown that the level of expression of cancer antigen 125 in tissue may be an independent prognostic indicator in late stage ovarian cancer. SUMMARY: Prognostic markers may potentially help to individualize treatment within subgroups of patients. In a recent study the level...

  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. Suppression of blastogenesis and proliferation of activated CD4(+) T cells: intravenous immunoglobulin (IVIg) versus novel anti-human leucocyte antigen (HLA)-E monoclonal antibodies mimicking HLA-I reactivity of IVIg.

    Science.gov (United States)

    Ravindranath, M H; Terasaki, P I; Pham, T; Jucaud, V; Kawakita, S

    2014-10-01

    Activated CD4(+) T cells undergo blastogenesis and proliferation and they express several surface receptors, including β2-microglobulin-free human leucocyte antigen (HLA) heavy chains (open conformers). Intravenous immunoglobulin (IVIg) suppresses activated T cells, but the mechanism is unclear. IVIg reacts with HLA-Ia/Ib antigens but its reactivity is lost when the anti-HLA-E Ab is adsorbed out. Anti-HLA-E antibodies may bind to the peptides shared by HLA-E and the HLA-I alleles. These shared peptides are cryptic in intact HLA, but exposed in open conformers. The hypothesis that anti-HLA-E monoclonal antibodies (mAbs) that mimic HLA-I reactivity of IVIg may suppress activated T cells by binding to the shared peptides of the open conformers on the T cell surface was tested by examining the relative binding affinity of those mAbs for open conformers coated on regular beads and for intact HLA coated on iBeads, and by comparing the effects on the suppression of phytohaemagglutinin (PHA)-activated T cells of three entities: IVIg, anti-HLA-E mAbs that mimic IVIg [Terasaki Foundation Laboratory (TFL)-006 and (TFL)-007]; and anti-HLA-E antibodies that do not mimic IVIg (TFL-033 and TFL-037). Suppression of blastogenesis and proliferation of those T cells by both IVIg and the anti-HLA-E mAbs was dose-dependent, the dose required with mAbs 50-150-fold lower than with IVIg. TFL-006 and TFL-007 significantly suppressed blastogenesis and proliferation of activated CD4(+) T cells, but neither the non-IVIg-mimicking mAbs nor control antibodies did so. The suppression may be mediated by Fab-binding of TFL-006/TFL-007 to the exposed shared peptides. The mAb binding to the open conformer may signal T cell deactivation because the open conformers have an elongated cytoplasmic tail with phosphorylation sites (tryosine(320)/serine(335)). © 2014 British Society for Immunology.

  11. Nonvirion Antigens Produced by Herpes Simplex Viruses 1 and 2

    Science.gov (United States)

    Tarro, Giulio; Sabin, Albert B.

    1973-01-01

    Of nine herpes simplex virus 1 strains (from lip, mouth, throat, cornea, or brain) only five produced enough nonvirion antigen (i.e., not a structural component of the virus) to be detected by complement fixation with specially prepared, virion-absorbed, type-1 guinea pig antisera, while the remaining four strains produced only enough of the same antigen to induce specific antibody in hyperimmunized guinea pigs. While the type 1 virion antiserum used reacted equally well by complement fixation with the type 1 and type 2 strains, the type 1 nonvirion antisera failed to react with nonvirion antigens produced by three type-2 (genital) strains. However, type 2 nonvirion antiserum reacted equally well with the three type 2 and four type 1 nonvirion antigens that were tested. It appears, therefore, that while herpes simplex virus 1 codes only for type 1 nonvirion antigen, herpes simplex 2 codes not only for an immunologically distinct type 2 nonvirion antigen but also for enough type 1 nonvirion antigen to stimulate antibody production for it. Herpes simplex 2 nonvirion antigen exhibited the same properties as type 1, i.e., its activity was lost on storage at 4° for 15 days, it was sedimented by centrifugation at 33,360 × g for 1 hr, and the maximum concentration was found at 3 hr in guinea pig kidney culture cells, but at 24 hr in HEp 2 and rabbit kidney culture cells. Sera from patients with genital lesions caused by herpes simplex virus 2, as well as from randomly selected adults, failed to react with either type 2 or type 1 nonvirion antigens. Accordingly, the basic information is now available to permit the use of these nonvirion antigens to determine the possible role of the herpes simplex viruses in certain human cancers. PMID:4352219

  12. Impact of highly active antiretroviral therapy (HAART) on the natural history of hepatitis B virus (HBV) and HIV coinfection: relationship between prolonged efficacy of HAART and HBV surface and early antigen seroconversion.

    Science.gov (United States)

    Miailhes, Patrick; Trabaud, Mary-Anne; Pradat, Pierre; Lebouché, Bertrand; Chevallier, Michèle; Chevallier, Philippe; Zoulim, Fabien; Trepo, Christian

    2007-09-01

    Coinfection with hepatitis B virus (HBV) in human immunodeficiency virus (HIV)-infected patients is common. However, little is known about the natural history of chronic hepatitis B in HIV-infected populations, especially the impact of highly active antiretroviral therapy (HAART) on the outcome of HBV early antigen (HBeAg) and HBV surface antigen (HBsAg) status. The characteristics of 92 patients coinfected with HIV and HBV were retrospectively assessed before and after HAART and lamivudine treatment to determine the impact of treatment on chronic hepatitis B and factors associated with HBeAg and/or HBsAg seroconversion. During follow-up, 82 patients received antiretroviral therapy, 79 of whom received HAART. Twenty-eight of the 76 patients who were administered lamivudine therapy developed lamivudine resistance mutations. While receiving antiretroviral therapy, 10 of 59 HBeAg-positive patients developed antibody to HBeAg, 3 of 10 cleared HBsAg, and 2 of 3 developed antibody to HBsAg. Two of 23 HBeAg-negative patients cleared HBsAg and developed antibody to HBsAg. HBeAg and/or HBsAg seroconversion combined with an undetectable HBV DNA level (i.e., an HBV response) correlated with a sustained HIV response (P=.001), shorter duration of antiretroviral therapy (P=.058), and more-severe disease, as evaluated by Centers for Disease Control and Prevention staging (for stage B vs. stage A, P=.029; for stage C vs. stage A, P=.069). For patients with elevated baseline alanine aminotransferase levels, the HBV response correlated significantly with a greater increase in CD4 cell count while receiving HAART. In HIV-HBV-coinfected patients, HBV response correlated with a sustained HIV response to antiretroviral therapy, usually HAART including lamivudine.

  13. Antigen-presenting cells exposed to Lactobacillus acidophilus NCFM, Bifidobacterium bifidum BI-98, and BI-504 reduce regulatory T cell activity

    DEFF Research Database (Denmark)

    Schmidt, Esben Gjerløff Wedebye; Claesson, Mogens Helweg; Jensen, Simon Skjøde

    2010-01-01

    BACKGROUND:: The effect in vitro of six different probiotic strains including Lactobacillus acidophilus NCFM, Lactobacillus salivarius Ls-33, Lactobacillus paracasei subsp. paracasei YS8866441, Lactobacillus plantarum Lp-115, Bifidobacterium bifidum BI-504 and BI-98 was studied on splenic....... acidophilus NCFM consistently reduced the suppressive activity of Tregs. The suppressive activity was analyzed using fractionated components of the probiotics, and showed that a component of the cell wall is responsible for the decreased Treg activity in the system. The probiotic-induced suppression of Treg...

  14. A Role of Sp1 Binding Motifs in Basal and Large T-Antigen-Induced Promoter Activities of Human Polyomavirus HPyV9 and Its Variant UF-1

    Directory of Open Access Journals (Sweden)

    Ugo Moens

    2017-11-01

    Full Text Available Human polyomavirus 9 (HPyV9 was originally detected in the serum of a renal transplant patient. Seroepidemiological studies showed that ~20–50% of the human population have antibodies against this virus. HPyV9 has not yet been associated with any disease and little is known about the route of infection, transmission, host cell tropism, and genomic variability in circulating strains. Recently, the HPyV9 variant UF-1 with an eight base-pair deletion, a thirteen base-pair insertion and with point mutations, creating three putative Sp1 binding sites in the late promoter was isolated from an AIDS patient. Transient transfection studies with a luciferase reporter plasmid driven by HPyV9 or UF1 promoter demonstrated that UF1 early and late promoters were stronger than HPyV9 promoters in most cell lines, and that the UF1 late promoter was more potently activated by HPyV9 large T-antigen (LTAg. Mutation of two Sp1 motifs strongly reduced trans-activation of the late UF1 promoter by HPyV9 LTAg in HeLa cells. In conclusion, the mutations in the UF1 late promoter seem to strengthen its activity and its response to stimulation by HPyV9 LTAg in certain cells. It remains to be investigated whether these promoter changes have an influence on virus replication and affect the possible pathogenic properties of the virus.

  15. COLONOSCOPY AND CARCINOEMBRYONIC ANTIGEN VARIATIONS

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    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.

  16. Monocytes and the 38kDa-antigen of mycobacterium tuberculosis modulate natural killer cell activity and their cytolysis directed against ovarian cancer cell lines

    Directory of Open Access Journals (Sweden)

    Gottschalk Nina

    2012-10-01

    Full Text Available Abstract Background Despite strong efforts to improve clinical outcome of ovarian cancer patients by conventional and targeted immuno-based therapies, the prognosis of advanced ovarian cancer is still poor. Natural killer (NK cells mediate antibody-dependent cellular cytotoxicity (ADCC, release immunostimulatory cytokines and thus function as potent anti-tumour effector cells. However, tumour cells developed mechanisms to escape from an effective immune response. So highly immunogenic substances, like the 38 kDa-preparation of M. tuberculosis, PstS-1, are explored for their potential to enhance cancer-targeted immune responses. In this study we examined the modulation of different NK cell functions by accessory monocytes and PstS-1. We focussed on NK cell activation as well as natural and antibody-dependent cellular cytotoxicity directed against epidermal-growth-factor-receptor (EGFR-positive ovarian cancer cell lines. Methods Activation, cytokine release and cytotoxicity of NK cells stimulated by monocytes and PstS-1 were determined by FACS-analysis, ELISA, Bioplex assay and quantitative polymerase-chain reaction (qPCR. Transwell assays were used to discriminate cell-cell contact-dependent from contact-independent mechanisms. Five ovarian cancer cell lines (A2780, IGROV-1, OVCAR-3, OVCAR-4 and SKOV-3 with different EGFR-expression were used as target cells for natural and antibody-dependent cellular cytotoxicity assays. Cetuximab (anti-EGFR-antibody was used for ADCC studies. Results Our data show that monocytes effectively enhance activation as well natural and antibody-dependent cytolytic activity of NK cells. PstS-1 directly stimulated monocytes and further activated monocyte-NK-co-cultures. However, PstS-1 did not directly influence purified NK cells and did also not affect natural and antibody-dependent cellular cytotoxicity directed against EGFR-positive ovarian cancer cells, even in presence of monocytes. Direct cell-cell contact between

  17. Multiple steady states and the form of response functions to antigen in a model for the initiation of T-cell activation.

    Science.gov (United States)

    Rendall, Alan D; Sontag, Eduardo D

    2017-11-01

    The aim of this paper is to study the qualitative behaviour predicted by a mathematical model for the initial stage of T-cell activation. The state variables in the model are the concentrations of phosphorylation states of the T-cell receptor (TCR) complex and the phosphatase SHP-1 in the cell. It is shown that these quantities cannot approach zero and that the model possesses more than one positive steady state for certain values of the parameters. It can also exhibit damped oscillations. It is proved that the chemical concentration which represents the degree of activation of the cell, that of the maximally phosphorylated form of the TCR complex, is, in general, a non-monotone function of the activating signal. In particular, there are cases where there is a value of the dissociation constant of the ligand from the receptor which produces a maximal activation of the T cell. This suggests that mechanisms taking place in the first few minutes after activation and included in the model studied in this paper suffice to explain the optimal dissociation time seen in experiments. In this way, the results of certain simulations in the literature have been confirmed rigorously and some important features which had not previously been seen have been discovered.

  18. Classification of human leukocyte antigen (HLA) supertypes

    DEFF Research Database (Denmark)

    Wang, Mingjun; Claesson, Mogens H

    2014-01-01

    , 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......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...... 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...

  19. Mechanisms Mediating Antigenic Variation in Trypanosoma brucei

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    Rudenko Gloria

    1999-01-01

    Full Text Available Antigenic variation in Trypanosoma brucei is a highly sophisticated survival strategy involving switching between the transcription of one of an estimated thousand variant surface glycoprotein (VSG genes. Switching involves either transcriptional control, resulting in switching between different VSG expression sites; or DNA rearrangement events slotting previously inactive VSG genes into an active VSG expression site. In recent years, considerable progress has been made in techniques allowing us to genetically modify infective bloodstream form trypanosomes. This is allowing us to reengineer VSG expression sites, and look at the effect on the mechanisms subsequently used for antigenic variation. We can now begin a dissection of a highly complicated survival strategy mediated by many different mechanisms operating simultaneously.

  20. Dichotomy of the T cell response to Leishmania antigens in patients suffering from cutaneous leishmaniasis; absence or scarcity of Th1 activity is associated with severe infections

    DEFF Research Database (Denmark)

    Gaafar, A; Kharazmi, A; Ismail, A

    1995-01-01

    The T cell response was studied in 25 patients suffering from cutaneous leishmaniasis caused by Leishmania major with severe (n = 10) and mild (n = 15) disease manifestations. Peripheral blood mononuclear cells (PBMC) from the patients were activated by sonicates of Leishmania promastigotes (LMP...

  1. Antigen-specific helper activity in serum of mice primed with sheep red cells I. Definition of the test system and comparison with other systems

    NARCIS (Netherlands)

    Dijk, H. van; Rademaker, P.M.; Slotboom, A.; Willers, J.M.

    An adoptive transfer system is described to measure serum helper activity in the primary antibody response to sheep red blood cells (SRBC). Mice injected with a high dose of cyclophosphamide and reconstituted with rabbit anti-thymocyte serum-treated spleen cells were used as recipients. Serum

  2. Reconstitution of EBV latent but not lytic antigen-specific CD4(+) and CD8(+) T cells after HIV treatment with highly active antiretroviral therapy

    NARCIS (Netherlands)

    Piriou, Erwan; Jansen, Christine A.; van Dort, Karel; de Cuyper, Iris; Nanlohy, Nening M.; Lange, Joep M. A.; van Oers, Marinus H. J.; Miedema, Frank; van Baarle, Debbie

    2005-01-01

    The incidence of (EBV-rlelated) malignancies in HIV-infected subjects has declined since the introduction of highly active antiretroviral therapy (HAART). To investigate the effect of HAART on EBV infection, we performed a longitudinal analysis of the T cell response to both a latent and a lytic Ag

  3. Serum levels of soluble forms of T cell activation antigens CD27 and CD25 in systemic lupus erythematosus in relation with lymphocytes count and disease course

    NARCIS (Netherlands)

    A.J.G. Swaak (Antonius); R.Q. Hintzen (Rogier); V. Huysen (V.); H.G. van den Brink (H.); J.T. Smeenk (J.)

    1995-01-01

    textabstractSystemic lupus erythematosus (SLE) patients are characterized by a low lymphocyte count, which is considered a specific disease marker and is related to disease activity. The membrane bound molecules CD25 and CD27 are expressed and released in a soluble CD25 (sCD25) and soluble CD27

  4. Detection of tissue factor antigen and coagulation activity in coronary artery thrombi isolated from patients with ST-segment elevation acute myocardial infarction.

    Directory of Open Access Journals (Sweden)

    Tullio Palmerini

    Full Text Available INTRODUCTION: Although ruptured atherosclerotic plaques have been extensively analyzed, the composition of thrombi causing arterial occlusion in patients with ST-segment elevation acute myocardial infarction has been less thoroughly investigated. We sought to investigate whether coagulant active tissue factor can be retrieved in thrombi of patients with STEMI undergoing primary percutaneous coronary intervention. METHODS: Nineteen patients with ST-segment elevation acute myocardial infarction referred for primary percutaneous coronary intervention were enrolled in this study. Coronary thrombi aspirated from coronary arteries were routinely processed for paraffin embedding and histological evaluation (4 patients or immediately snap frozen for evaluation of tissue factor activity using a modified aPTT test (15 patients. Immunoprecipitation followed by immunoblotting was also performed in 12 patients. RESULTS: Thrombi aspirated from coronary arteries showed large and irregular areas of tissue factor staining within platelet aggregates, and in close contact with inflammatory cells. Some platelet aggregates stained positive for tissue factor, whereas others did not. Monocytes consistently stained strongly for tissue factor, neutrophils had a more variable and irregular tissue factor staining, and red blood cells did not demonstrate staining for tissue factor. Median clotting time of plasma samples containing homogenized thrombi incubated with a monoclonal antibody that specifically inhibits tissue factor-mediated coagulation activity (mAb 5G9 were significantly longer than their respective controls (88.9 seconds versus 76.5 seconds, respectively; p<0.001. Tissue factor was also identified by immunoprecipitation in 10 patients, with significant variability among band intensities. CONCLUSIONS: Active tissue factor is present in coronary artery thrombi of patients with ST-segment elevation acute myocardial infarction, suggesting that it contributes to

  5. Circulating precursor CCR7(lo)PD-1(hi) CXCR5⁺ CD4⁺ T cells indicate Tfh cell activity and promote antibody responses upon antigen reexposure.

    Science.gov (United States)

    He, Jing; Tsai, Louis M; Leong, Yew Ann; Hu, Xin; Ma, Cindy S; Chevalier, Nina; Sun, Xiaolin; Vandenberg, Kirsten; Rockman, Steve; Ding, Yan; Zhu, Lei; Wei, Wei; Wang, Changqi; Karnowski, Alexander; Belz, Gabrielle T; Ghali, Joanna R; Cook, Matthew C; Riminton, D Sean; Veillette, André; Schwartzberg, Pamela L; Mackay, Fabienne; Brink, Robert; Tangye, Stuart G; Vinuesa, Carola G; Mackay, Charles R; Li, Zhanguo; Yu, Di

    2013-10-17

    Follicular B helper T (Tfh) cells support high affinity and long-term antibody responses. Here we found that within circulating CXCR5⁺ CD4⁺ T cells in humans and mice, the CCR7(lo)PD-1(hi) subset has a partial Tfh effector phenotype, whereas CCR7(hi)PD-1(lo) cells have a resting phenotype. The circulating CCR7(lo)PD-1(hi) subset was indicative of active Tfh differentiation in lymphoid organs and correlated with clinical indices in autoimmune diseases. Thus the CCR7(lo)PD-1(hi) subset provides a biomarker to monitor protective antibody responses during infection or vaccination and pathogenic antibody responses in autoimmune diseases. Differentiation of both CCR7(hi)PD-1(lo) and CCR7(lo)PD-1(hi) subsets required ICOS and BCL6, but not SAP, suggesting that circulating CXCR5⁺ helper T cells are primarily generated before germinal centers. Upon antigen reencounter, CCR7(lo)PD-1(hi) CXCR5⁺ precursors rapidly differentiate into mature Tfh cells to promote antibody responses. Therefore, circulating CCR7(lo)PD-1(hi) CXCR5⁺ CD4⁺ T cells are generated during active Tfh differentiation and represent a new mechanism of immunological early memory. Copyright © 2013 Elsevier Inc. All rights reserved.

  6. 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.

  7. Natural selection promotes antigenic evolvability.

    Directory of Open Access Journals (Sweden)

    Christopher J Graves

    Full Text Available 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

  8. Epicutaneous sensitization with protein antigen

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    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.

  9. [Biological function of cancer-associated carbohydrate antigens].

    Science.gov (United States)

    Kannagi, R

    1996-06-01

    An important outcome of the monoclonal antibody approach for cancer-associated antigens is that cell-surface carbohydrates have been shown to be very important cancer-associated antigens. These antigens are currently classified into several groups. The first group has the sugar determinant carried by so-called type 1 chain carbohydrates, with a backbone structure composed of the Gal beta 1-->3GlcNAc beta repeating unit. The antigens in this group are utilized mainly for the diagnosis of cancers in the pancreas, biliary tract and other digestive organs. This group includes the well-known serum tumor marker, the 2 -->3 sialyl Le(a) antigen, which is detected by N19-9 and other antibodies. This group also includes DU-PAN-2, which was recently confirmed to be the sialyl Lec. The second group has the polysaccharide determinant carried by so-called type 2 chain carbohydrates, the characteristic feature of which is a backbone structure composed of the Gal beta1 -->4GlcNAc beta repeating unit. This group includes the tumor markers, sialyl SSEA-1, CSLEX-1 or sialyl Lewis X, and is used for the diagnosis of cancers originating in the lung, ovary and digestive organs. The third group has the antigenic determinant carried by the innermost core structures in O-linked carbohydrate side chains. The example of this group is the sialyl Tn antigen, which is detected in ovarian cancers. This group also includes the recently described carbohydrate determinant called Fl alpha antigen, which is frequently expressed in gastric cancer cells. Some of the antigens in the first and second groups such as sialyl Le(a) and sialyl Le(x), serve as ligands for E-selectin, a cell adhesion molecule expressed on activated human endothelial cells, and play significant roles in hematogenous metastasis of cancer.

  10. Comprehensive Approach for Identifying the T Cell Subset Origin of CD3 and CD28 Antibody-Activated Chimeric Antigen Receptor-Modified T Cells.

    Science.gov (United States)

    Schmueck-Henneresse, Michael; Omer, Bilal; Shum, Thomas; Tashiro, Haruko; Mamonkin, Maksim; Lapteva, Natalia; Sharma, Sandhya; Rollins, Lisa; Dotti, Gianpietro; Reinke, Petra; Volk, Hans-Dieter; Rooney, Cliona M

    2017-07-01

    The outcome of therapy with chimeric Ag receptor (CAR)-modified T cells is strongly influenced by the subset origin of the infused T cells. However, because polyclonally activated T cells acquire a largely CD45RO(+)CCR7(-) effector memory phenotype after expansion, regardless of subset origin, it is impossible to know which subsets contribute to the final T cell product. To determine the contribution of naive T cell, memory stem T cell, central memory T cell, effector memory T cell, and terminally differentiated effector T cell populations to the CD3 and CD28-activated CAR-modified T cells that we use for therapy, we followed the fate and function of individually sorted CAR-modified T cell subsets after activation with CD3 and CD28 Abs (CD3/28), transduction and culture alone, or after reconstitution into the relevant subset-depleted population. We show that all subsets are sensitive to CAR transduction, and each developed a distinct T cell functional profile during culture. Naive-derived T cells showed the greatest rate of proliferation but had more limited effector functions and reduced killing compared with memory-derived populations. When cultured in the presence of memory T cells, naive-derived T cells show increased differentiation, reduced effector cytokine production, and a reduced reproliferative response to CAR stimulation. CD3/28-activated T cells expanded in IL-7 and IL-15 produced greater expansion of memory stem T cells and central memory T cell-derived T cells compared with IL-2. Our strategy provides a powerful tool to elucidate the characteristics of CAR-modified T cells, regardless of the protocol used for expansion, reveals the functional properties of each expanded T cell subset, and paves the way for a more detailed evaluation of the effects of manufacturing changes on the subset contribution to in vitro-expanded T cells. Copyright © 2017 by The American Association of Immunologists, Inc.

  11. Detection of Tissue Factor Antigen and Coagulation Activity in Coronary Artery Thrombi Isolated from Patients with ST-Segment Elevation Acute Myocardial Infarction

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    Palmerini, Tullio; Tomasi, Luciana; Barozzi, Chiara; Della Riva, Diego; Mariani, Andrea; Taglieri, Nevio; Leone, Ornella; Ceccarelli, Claudio; De Servi, Stefano; Branzi, Angelo; Genereux, Philippe; Stone, Gregg W.; Ahamed, Jasimuddin

    2013-01-01

    Introduction Although ruptured atherosclerotic plaques have been extensively analyzed, the composition of thrombi causing arterial occlusion in patients with ST-segment elevation acute myocardial infarction has been less thoroughly investigated. We sought to investigate whether coagulant active tissue factor can be retrieved in thrombi of patients with STEMI undergoing primary percutaneous coronary intervention. Methods Nineteen patients with ST-segment elevation acute myocardial infarction referred for primary percutaneous coronary intervention were enrolled in this study. Coronary thrombi aspirated from coronary arteries were routinely processed for paraffin embedding and histological evaluation (4 patients) or immediately snap frozen for evaluation of tissue factor activity using a modified aPTT test (15 patients). Immunoprecipitation followed by immunoblotting was also performed in 12 patients. Results Thrombi aspirated from coronary arteries showed large and irregular areas of tissue factor staining within platelet aggregates, and in close contact with inflammatory cells. Some platelet aggregates stained positive for tissue factor, whereas others did not. Monocytes consistently stained strongly for tissue factor, neutrophils had a more variable and irregular tissue factor staining, and red blood cells did not demonstrate staining for tissue factor. Median clotting time of plasma samples containing homogenized thrombi incubated with a monoclonal antibody that specifically inhibits tissue factor-mediated coagulation activity (mAb 5G9) were significantly longer than their respective controls (88.9 seconds versus 76.5 seconds, respectively; pthrombi of patients with ST-segment elevation acute myocardial infarction, suggesting that it contributes to activate the coagulation cascade ensuing in coronary thrombosis. PMID:24349079

  12. Activation of antigen-exposed iMC-DCs at the "right place" and "right time" promotes potent anti-tumor immunity.

    Science.gov (United States)

    Spencer, David M

    2012-05-01

    To better control the "licensing" of pro-Th1 dendritic cells (DCs), Spencer and colleagues have developed a synthetic ligand-inducible chimeric receptor, iMyD88/CD40 (iMC), incorporating synergistic Toll-like receptor (TLR) and costimulatory signaling elements, permitting DC regulation in vivo within the context of an immunological synapse. This novel technology results in potent anti-cancer activity.

  13. The Antigen Presenting Cells Instruct Plasma Cell Differentiation

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    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.

  14. A Diet, Physical Activity, and Stress Reduction Intervention in Men with Rising Prostate-Specific Antigen (PSA) after Treatment for Prostate Cancer

    Science.gov (United States)

    Hébert, James R.; Hurley, Thomas G.; Harmon, Brook E.; Heiney, Sue; Hebert, Christine J.; Steck, Susan E.

    2011-01-01

    Background Nearly 35% of men treated for prostate cancer (PrCA) will experience biochemically defined recurrence, noted by a rise in PSA, within ten years of definitive therapy. Diet, physical activity, and stress reduction may affect tumor promotion and disease progression. Methods A randomized trial of an intensive diet, physical activity, and meditation intervention was conducted in men with rising post-treatment PSA after definitive treatment for PrCA. Intention-to-treat methods were used to compare usual care to the intervention in 47 men with complete data. Signal detection methods were used to identify dietary factors associated with PSA change. Results The intervention and control groups did not differ statistically on any demographic or disease-related factor. Although the intervention group experienced decreases of 39% in intakes of saturated fatty acid (SFA as percent of total calories) (p<0.0001) and 12% in total energy intake (218 kcal/day p<0.05)], no difference in PSA change was observed by intervention status. Signal detection methods indicated that in men increasing their consumption of fruit, 56% experienced no rise in PSA (vs. 29% in men who did not increase their fruit intake). Among men who increased fruit and fiber intakes, PSA increased in 83% of participants who also increased saturated fatty acid intake (vs. 44% in participants who decreased or maintained saturated fatty acid intake). Conclusion Results are discussed in the context of conventional treatment strategies that were more aggressive when this study was being conducted in the mid-2000s. Positive health changes in a number of lifestyle parameters were observed with the intervention, and both increased fruit and reduced saturated fat intakes were associated with maintaining PSA levels in men with biochemically recurrent disease. PMID:22018935

  15. A diet, physical activity, and stress reduction intervention in men with rising prostate-specific antigen after treatment for prostate cancer.

    Science.gov (United States)

    Hébert, James R; Hurley, Thomas G; Harmon, Brook E; Heiney, Sue; Hebert, Christine J; Steck, Susan E

    2012-04-01

    Nearly 35% of men treated for prostate cancer (PrCA) will experience biochemically defined recurrence, noted by a rise in PSA, within 10 years of definitive therapy. Diet, physical activity, and stress reduction may affect tumor promotion and disease progression. A randomized trial of an intensive diet, physical activity, and meditation intervention was conducted in men with rising post-treatment PSA after definitive treatment for PrCA. Intention-to-treat methods were used to compare usual care to the intervention in 47 men with complete data. Signal detection methods were used to identify dietary factors associated with PSA change. The intervention and control groups did not differ statistically on any demographic or disease-related factor. Although the intervention group experienced decreases of 39% in intakes of saturated fatty acid (SFA as percent of total calories) (p<0.0001) and 12% in total energy intake (218 kcal/day, p<0.05)], no difference in PSA change was observed by intervention status. Signal detection methods indicated that in men increasing their consumption of fruit, 56% experienced no rise in PSA (vs. 29% in men who did not increase their fruit intake). Among men who increased fruit and fiber intakes, PSA increased in 83% of participants who also increased saturated fatty acid intake (vs. 44% in participants who decreased or maintained saturated fatty acid intake). Results are discussed in the context of conventional treatment strategies that were more aggressive when this study was being conducted in the mid-2000s. Positive health changes in a number of lifestyle parameters were observed with the intervention, and both increased fruit and reduced saturated fat intakes were associated with maintaining PSA levels in men with biochemically recurrent disease. Copyright © 2011 Elsevier Ltd. All rights reserved.

  16. Continuous activation of the CD122/STAT-5 signaling pathway during selection of antigen-specific regulatory T cells in the murine thymus.

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    Jérémie D Goldstein

    Full Text Available Signaling events affecting thymic selection of un-manipulated polyclonal natural CD25(+foxp3(+ regulatory T cells (nTreg have not been established ex vivo. Here, we report a higher frequency of phosphorylated STAT-5 (pSTAT-5 in nTreg cells in the adult murine thymus and to a lesser extent in the periphery, compared to other CD4(+CD8(- subsets. In the neonatal thymus, the numbers of pSTAT-5(+ cells in CD25(+foxp3(- and nTreg cells increased in parallel, suggesting that pSTAT-5(+CD25(+foxp3(- cells might represent the precursors of foxp3(+ regulatory T cells. This "specific" pSTAT-5 expression detected in nTreg cells ex vivo was likely due to a very recent signal given by IL-2/IL-15 cytokines in vivo since (i it disappeared rapidly if cells were left unstimulated in vitro and (ii was also observed if total thymocytes were stimulated in vitro with saturating amounts of IL-2 and/or IL-15 but not IL-7. Interestingly, STAT-5 activation upon IL-2 stimulation correlated better with foxp3 and CD122 than with CD25 expression. Finally, we show that expression of an endogenous superantigen strongly affected the early Treg cell repertoire but not the proportion of pSTAT-5(+ cells within this repertoire. Our results reveal that continuous activation of the CD122/STAT-5 signaling pathway characterize regulatory lineage differentiation in the murine thymus.

  17. Impaired NK-mediated regulation of T-cell activity in multiple sclerosis is reconstituted by IL-2 receptor modulation

    Science.gov (United States)

    Gross, Catharina C.; Schulte-Mecklenbeck, Andreas; Rünzi, Anna; Kuhlmann, Tanja; Posevitz-Fejfár, Anita; Schwab, Nicholas; Schneider-Hohendorf, Tilman; Herich, Sebastian; Held, Kathrin; Konjević, Matea; Hartwig, Marvin; Dornmair, Klaus; Hohlfeld, Reinhard; Ziemssen, Tjalf; Klotz, Luisa; Meuth, Sven G.; Wiendl, Heinz

    2016-01-01

    Multiple sclerosis (MS) is a chronic inflammatory autoimmune disease of the central nervous system (CNS) resulting from a breakdown in peripheral immune tolerance. Although a beneficial role of natural killer (NK)-cell immune-regulatory function has been proposed, it still needs to be elucidated whether NK cells are functionally impaired as part of the disease. We observed NK cells in active MS lesions in close proximity to T cells. In accordance with a higher migratory capacity across the blood–brain barrier, CD56bright NK cells represent the major intrathecal NK-cell subset in both MS patients and healthy individuals. Investigating the peripheral blood and cerebrospinal fluid of MS patients treated with natalizumab revealed that transmigration of this subset depends on the α4β1 integrin very late antigen (VLA)-4. Although no MS-related changes in the migratory capacity of NK cells were observed, NK cells derived from patients with MS exhibit a reduced cytolytic activity in response to antigen-activated CD4+ T cells. Defective NK-mediated immune regulation in MS is mainly attributable to a CD4+ T-cell evasion caused by an impaired DNAX accessory molecule (DNAM)-1/CD155 interaction. Both the expression of the activating NK-cell receptor DNAM-1, a genetic alteration consistently found in MS-association studies, and up-regulation of the receptor’s ligand CD155 on CD4+ T cells are reduced in MS. Therapeutic immune modulation of IL-2 receptor restores impaired immune regulation in MS by increasing the proportion of CD155-expressing CD4+ T cells and the cytolytic activity of NK cells. PMID:27162345

  18. Cyclosporin A promotes proliferating cell nuclear antigen expression and migration of human cytotrophoblast cells via the mitgen-activated protein kinase-3/1-mediated nuclear factor-κB signaling pathways.

    Science.gov (United States)

    Wang, Song-Cun; Yu, Min; Li, Yan-Hong; Piao, Hai-Lan; Tang, Chuan-Lin; Sun, Chan; Zhu, Rui; Li, Ming Qing; Jin, Li-Ping; Li, Da-Jin; Du, Mei-Rong

    2013-01-01

    Our previous studies have demonstrated that cyclosporin A (CsA) promotes the proliferation and migration of human trophoblasts via the mitgen-activated protein kinase-3/1 (MAPK3/1) pathway. In the present study, we further investigated the role of nuclear factor (NF)-κB in the CsA-induced trophoblast proliferating cell nuclear antigen (PCNA) expression and migration, and its relationship to MAPK3/1 signal. Flow cytometry was used to analyze the expression of PCNA in trophoblasts. The migration of human primary trophoblasts was determined by wound-healing assay and transwell migration assay. Western blot analysis was performed to evaluate the activation of NF-κB p65 and NF-κB inhibitory protein I-κB in human trophoblasts. We found that treatment with CsA promotes PCNA expression and migration of human trophoblast in a dose-associated manner. Blocking of the MAPK3/1 signal abrogated the enhanced PCNA expression and migration in trophoblasts by CsA. In addition, CsA increased the phosphorylation of NF-κB p65 and the inhibitor I-κB in human trophoblasts in a time-related manner. Pretreatment with MAPK3/1 inhibitor U0126 abrogated the phosphorylation of NF-κB p65 and I-κB. Accordingly, the CsA-induced enhancement of PCNA expression and migration in trophoblasts was also decreased. This CsA-induced enhancement in the expression and migration of trophoblasts was abolished by pretreatment with pyrrolidine dithiocarbamate, a specific NF-κB inhibitor. Thus, our results suggest that CsA promotes PCNA expression and migration of human trophoblasts via MAPK-mediated NF-κB activation.

  19. Mouse bone marrow-derived dendritic cells can phagocytize the Sporothrix schenckii, and mature and activate the immune response by secreting interleukin-12 and presenting antigens to T lymphocytes.

    Science.gov (United States)

    Kusuhara, Masahiro; Qian, Hua; Li, Xiaoguang; Tsuruta, Daisuke; Tsuchisaka, Atsunari; Ishii, Norito; Ohata, Chika; Furumura, Minao; Hashimoto, Takashi

    2014-05-01

    In sporotrichosis, dermal dendritic cells were considered to participate in induction of the immune responses against Sporothrix schenckii infection. However, it is still unclear whether and how dermal dendritic cells were involved in the progress. To clarify the pathogenic role of dermal dendritic cells (DC) in sporotrichosis, we examined the phagocytosis, maturation stages, cytokine production and antigen-presenting ability of mouse bone marrow-derived DC after stimulation with S. schenckii. By analysis of flow cytometry, electron microscope and confocal microscope, mouse bone marrow-derived DC were proved to be able to phagocytize the S. schenckii. The increased expression of CD40, CD80 and CD86 on the surface of S. schenckii-pulsed mouse bone marrow-derived DC was detected by flow cytometer, indicating that the S. schenckii-pulsed mouse bone marrow-derived DC underwent the maturation program. The secretory enhancement of interleukin (IL)-12, but not IL-4, was found in S. schenckii-pulsed mouse bone marrow-derived DC, suggesting the possible activation of T-helper 1 prone immune responses. Furthermore, S. schenckii-pulsed mouse bone marrow-derived DC were demonstrated to be capable of inducing the proliferation of T lymphocytes from BALB/c mice that were pre-sensitized with S. schenckii. Together, all the results implied that dermal DC may participate in the induction of immune responses against S. schenckii infection in sporotrichosis. © 2014 Japanese Dermatological Association.

  20. Relationships between Th1 or Th2 iNKT cell activity and structures of CD1d-antigen complexes: meta-analysis of CD1d-glycolipids dynamics simulations.

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    Xavier Laurent

    2014-11-01

    Full Text Available A number of potentially bioactive molecules can be found in nature. In particular, marine organisms are a valuable source of bioactive compounds. The activity of an α-galactosylceramide was first discovered in 1993 via screening of a Japanese marine sponge (Agelas mauritanius. Very rapidly, a synthetic glycololipid analogue of this natural molecule was discovered, called KRN7000. Associated with the CD1d protein, this α-galactosylceramide 1 (KRN7000 interacts with the T-cell antigen receptor to form a ternary complex that yields T helper (Th 1 and Th2 responses with opposing effects. In our work, we carried out molecular dynamics simulations (11.5 µs in total involving eight different ligands (conducted in triplicate in an effort to find out correlation at the molecular level, if any, between chemical modulation of 1 and the orientation of the known biological response, Th1 or Th2. Comparative investigations of human versus mouse and Th1 versus Th2 data have been carried out. A large set of analysis tools was employed including free energy landscapes. One major result is the identification of a specific conformational state of the sugar polar head, which could be correlated, in the present study, to the biological Th2 biased response. These theoretical tools provide a structural basis for predicting the very different dynamical behaviors of α-glycosphingolipids in CD1d and might aid in the future design of new analogues of 1.

  1. Hemopoietic cell kinase (Hck) and p21-activated kinase 2 (PAK2) are involved in the down-regulation of CD1a lipid antigen presentation by HIV-1 Nef in dendritic cells.

    Science.gov (United States)

    Shinya, Eiji; Shimizu, Masumi; Owaki, Atsuko; Paoletti, Samantha; Mori, Lucia; De Libero, Gennaro; Takahashi, Hidemi

    2016-01-01

    Dendritic cells (DCs) play a major role in in vivo pathogenesis of HIV-1 infection. Therefore, DCs may provide a promising strategy to control and eventually overcome the fatal infection. Especially, immature DCs express all CD1s, the non-MHC lipid antigen -presenting molecules, and HIV-1 Nef down-regulates CD1 expression besides MHC. Moreover, CD1d-restricted CD4(+) NKT cells are infected by HIV-1, reducing the number of these cells in HIV-1-infected individuals. To understand the exact role of DCs and CD1-mediated immune response during HIV-1 infection, Nef down-regulation of CD1a-restricted lipid/glycolipid Ag presentation in iDCs was analyzed. We demonstrated the involvement of the association of Nef with hemopoietic cell kinase (Hck) and p21-activated kinase 2 (PAK2), and that Hck, which is expressed strongly in iDCs, augmented this mutual interaction. Hck might be another therapeutic target to preserve the function of HIV-1 infected DCs, which are potential reservoirs of HIV-1 even after antiretroviral therapy. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. The Impacts of Helicobacter Pylori Antigen Positivity on Ankylosing Spondylitis

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    Esra Erkol Ižnal

    2014-12-01

    Full Text Available Aim: We aimed to clarify the impacts of H. pylori infection on disease activity and clinical findings of AS. Material and Method: Forty-eight patients with AS were included in this study. The demographic data including age, sex, durations of the disease and medication of the patients were recorded. The laboratory analysis comprised Erythrocyte sedimentation rate (ESR, C-reactive protein (CRP and H. pylori antigen determination in gaita. The disease activity, functional disability and clinical status were assessed using the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI, The Bath Ankylosing Spondylitis Functional index (BASFI and The Bath Ankylosing Spondylitis Metrology Index (BASMI respectively. We divided patients according to H. pylori antigen positivity in gaita as H. pylori positive and negative patients.Results: The mean age of patients was 41.9 11.8. CRP levels were slightly but not significantly higher in patients with positive H. pylori antigen compared to those in patients without H. pylori antigen in gaita (p=0.08. There was no significant difference in terms of ESR levels, BASDAI, BASFI and BASMI scores in patients with positive H. pylori antigen compared to those in patients with negative H. pylori antigen in gaita (p-values were >0.05 for all. In regression model BASDAI score was found to have no relationship with H. pylori antigen positivity, ESR and CRP levels (p-values were >0.05 for all. Discussion: H. pylori seemed to have probable impacts on the disease activity of AS. Studies with greater patient population and longer follow-up periods are warranted to enlighten this issue.

  3. Influence of plasminogen activator inhibitor-1 (SERPINE1) 4G/5G polymorphism on circulating SERPINE-1 antigen expression in HCC associated with viral infection.

    Science.gov (United States)

    Divella, Rosa; Mazzocca, Antonio; Gadaleta, Cosimo; Simone, Giovanni; Paradiso, Angelo; Quaranta, Michele; Daniele, Antonella

    2012-01-01

    Hepatocarcinogenesis is heavily influenced by chronic hepatitis B (HBV) and C (HCV) infection. Elevated levels of plasminogen activator inhibitor-1 (SERPINE1/PAI-1) have been reported in patients with hepatocellular carcinoma (HCC) associated with viral infection. The gene encoding SERPINE1 is highly polymorphic and the frequently associated 4/5 guanosine (4G/5G) polymorphism in the gene promoter may influence its expression. Here, we investigated the distribution of genotypes and the frequency of alleles of the 4G/5G polymorphism in patients with HCC, the influence of the 4G/5G polymorphism on plasma SERPINE1 levels and its association with viral infection. A total of 75 patients with HCC were enrolled: 32 (42.6%) were HBV(+)/HCV(+), 11 (14.6%) were only HCV(+), and 32 (42.6%) were negative for both viruses. A control group of healthy donors was also enrolled (n=50). SERPINE1 plasma concentrations were determined by ELISA and the detection of the promoter 4G/5G polymorphism was performed by an allele-specific PCR analysis. We found that the frequency of both the 4G/4G genotype (p=0.02) and the 4G allele (p=0.006) were significantly higher in patients with HCC compared to the control group, and particularly higher in patients with HCC co-infected with HBV(+)/HCV(+) than in those with no viral infection. We also found that patients with the 4G/4G genotype had significantly higher plasma SERPINE1 protein levels when compared with patients with the 4G/5G or 5G/5G genotype (p5G SERPINE1 polymorphism with a higher level of SERPINE1 protein in patients with HCC with HBV(+)/HCV(+) than those without infection, suggest the presence of two distinct pathogenic mechanisms in hepatocarcinogenesis, depending on the etiology.

  4. Antigenic variation in Trypanosoma equiperdum.

    Science.gov (United States)

    Roth, C; Jacquemot, C; Giroud, C; Bringaud, F; Eisen, H; Baltz, T

    1991-01-01

    Trypanosoma equiperdum is an African trypanosome that causes dourine in horses. Like the other African trypanosomes, T. equiperdum escapes elimination by the immune system of its host by using an elaborate system of antigenic variant. The trypanosomes are covered by a coat consisting of a single protein called the variable surface glycoprotein (VSG) that acts as the major trypanosome immunogen. As the host responds to one VSG, trypanosomes covered with another VSG become dominant. There is a loose order of appearance of these VSG during the infection. The factors that affect the timing of VSG expression and the effective size of the VSG repertoire in T. equiperdum are reviewed. The VSG genes are generally activated by a process of duplicative transposition involving the duplication of a silent VSG gene and inserting a copy of the gene into an expression site. The order of VSG expression is related to the amount of homology between the silent gene and the expression site. The genes expressed late in infection lack extensive homology with the expression site and depend on homology with the gene in the expression site. The genes coding for VSG expressed late in infection are hybrid genes because of this mode of transfer. This transfer mechanism allows the trypanosome to create complex VSG genes from parts of several different silent genes that are each pseudogenes. Additionally, data are presented showing that only a limited portion of the VSG is actually seen by the host immune system. These factors indicate that the effective VSG repertoire is greater than the number of VSG genes in the trypanosome genome.

  5. Microfluidic squeezing for intracellular antigen loading in polyclonal B-cells as cellular vaccines

    Science.gov (United States)

    Lee Szeto, Gregory; van Egeren, Debra; Worku, Hermoon; Sharei, Armon; Alejandro, Brian; Park, Clara; Frew, Kirubel; Brefo, Mavis; Mao, Shirley; Heimann, Megan; Langer, Robert; Jensen, Klavs; Irvine, Darrell J.

    2015-05-01

    B-cells are promising candidate autologous antigen-presenting cells (APCs) to prime antigen-specific T-cells both in vitro and in vivo. However to date, a significant barrier to utilizing B-cells as APCs is their low capacity for non-specific antigen uptake compared to “professional” APCs such as dendritic cells. Here we utilize a microfluidic device that employs many parallel channels to pass single cells through narrow constrictions in high throughput. This microscale “cell squeezing” process creates transient pores in the plasma membrane, enabling intracellular delivery of whole proteins from the surrounding medium into B-cells via mechano-poration. We demonstrate that both resting and activated B-cells process and present antigens delivered via mechano-poration exclusively to antigen-specific CD8+T-cells, and not CD4+T-cells. Squeezed B-cells primed and expanded large numbers of effector CD8+T-cells in vitro that produced effector cytokines critical to cytolytic function, including granzyme B and interferon-γ. Finally, antigen-loaded B-cells were also able to prime antigen-specific CD8+T-cells in vivo when adoptively transferred into mice. Altogether, these data demonstrate crucial proof-of-concept for mechano-poration as an enabling technology for B-cell antigen loading, priming of antigen-specific CD8+T-cells, and decoupling of antigen uptake from B-cell activation.

  6. Effect of serum from various animal species on erythrocyte attachment of endotoxins and other bacterial antigens.

    Science.gov (United States)

    Praino, M; Neter, E

    1977-12-01

    Lipopolysaccharide O antigens (endotoxins) and other bacterial antigens readily attach to erythrocytes in vitro. This attachment is prevented by certain mammalian and avian sera. In this study, the inhibitory capacity of sera from lower animals was compared with that of higher animals for a total of 30 species. Antigens and the corresponding antisera included both crude O antigens and purified lipopolysaccharide preparations, the common enterobacterial antigen from Escherichia coli O14, the Vi antigen from Citrobacter ballerup, the polyribose-phosphate antigen from Haemophilus influenzae type b, and the crude teichoic acid antigen from Staphylococcus aureus. Antigen and serum mixtures were incubated at 37 degrees C for 30 min and used for erythrocyte modification; failure of hemagglutination by homologous bacterial antiserum provided evidence of inhibitory capacity. Sera from the classes Mammalia and Aves were very strong inhibitors; those of Reptilia and Osteichthyes were moderate in activity, displaying variation within the classes; those of Amphibia and Chondrichthyes were minimal inhibitors; and those of Merostomata, Crustacea, and Lamellibranchiata displayed questionable or no inhibitory capacity. Inhibitory sera were active with all antigens tested. The findings suggest evolution of inhibitory factors consistent with the theory of two diverging lines of animal phylogeny based on embryological criteria and closely parallel the observations of an endotoxin-altering capacity in vertebrate sera that is not found in invertebrate sera or hemolymph.

  7. Pulmonary dry powder vaccine of pneumococcal antigen loaded nanoparticles.

    Science.gov (United States)

    Kunda, Nitesh K; Alfagih, Iman M; Miyaji, Eliane N; Figueiredo, Douglas B; Gonçalves, Viviane M; Ferreira, Daniela M; Dennison, Sarah R; Somavarapu, Satyanarayana; Hutcheon, Gillian A; Saleem, Imran Y

    2015-11-30

    Pneumonia, caused by Streptococcus pneumoniae, mainly affects the immunocompromised, the very young and the old, and remains one of the leading causes of death. A steady rise in disease numbers from non-vaccine serotypes necessitates a new vaccine formulation that ideally has better antigen stability and integrity, does not require cold-chain and can be delivered non-invasively. In this study, a dry powder vaccine containing an important antigen of S. pneumoniae, pneumococcal surface protein A (PspA) that has shown cross-reactivity amongst serotypes to be delivered via the pulmonary route has been formulated. The formulation contains the antigen PspA adsorbed onto the surface of polymeric nanoparticles encapsulated in L-leucine microparticles that can be loaded into capsules and delivered via an inhaler. We have successfully synthesized particles of ∼150 nm and achieved ∼20 μg of PspA adsorption per mg of NPs. In addition, the spray-dried powders displayed a FPF of 74.31±1.32% and MMAD of 1.70±0.03 μm suggesting a broncho-alveolar lung deposition facilitating the uptake of the nanoparticles by dendritic cells. Also, the PspA released from the dry powders maintained antigen stability (SDS-PAGE), integrity (Circular dichroism) and activity (lactoferrin binding assay). Moreover, the released antigen also maintained its antigenicity as determined by ELISA. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Evaluation of three enzyme immunoassays for HIV-1 antigen detection.

    Science.gov (United States)

    Willoughby, P B; Lisker, A; Folds, J D

    1989-01-01

    Three enzyme immunoassay (EIA) methods for the detection of human immunodeficiency virus (HIV-1) were evaluated. Serum or plasma samples from 22 individuals seropositive for HIV-1 antibodies were tested with the Abbott, Coulter, and DuPont kits for presence of HIV-1 p24 antigen. Another 12 samples were tested with two kits only. Discordant results were obtained with 9 of 34 (26%) HIV-1-antibody-positive patient samples tested. Most of these discrepancies were found in samples containing less than 30 pg/ml of HIV-1 p24 core antigen. A sampling of sera from normal blood donors and patients with infectious or autoimmune diseases revealed a low level of false positive reactions, especially with sera containing antinuclear antibodies or rheumatoid factor. Noteworthy is the frequency of false positive reactions seen with the DuPont EIA for HIV-1 p24 antigen. 18/111 sera (16.2%) containing auto-antibodies tested positively with the DuPont HIV-1 p24 antigen EIA. The nonspecific nature of the test reactivity for 9/10 of these samples was confirmed using an HIV-1 p24 antigen inhibition assay. These findings are discussed in light of the need for HIV-1 antigen detection in the clinical laboratory and of other methods for HIV-1 detection: the polymerase chain reaction and measurements of reverse transcriptase activity.

  9. The Role of FcRn in Antigen Presentation

    Science.gov (United States)

    Baker, Kristi; Rath, Timo; Pyzik, Michal; Blumberg, Richard S.

    2014-01-01

    Immunoglobulins are unique molecules capable of simultaneously recognizing a diverse array of antigens and themselves being recognized by a broad array of receptors. The abundance specifically of the IgG subclass and the variety of signaling receptors to which it binds render this an important immunomodulatory molecule. In addition to the classical Fcγ receptors that bind IgG at the cell surface, the neonatal Fc receptor (FcRn) is a lifelong resident of the endolysosomal system of most hematopoietic cells where it determines the intracellular fate of both IgG and IgG-containing immune complexes (IgG IC). Cross-linking of FcRn by multivalent IgG IC within antigen presenting cells such as dendritic cells initiates specific mechanisms that result in trafficking of the antigen-bearing IgG IC into compartments from which the antigen can successfully be processed into peptide epitopes compatible with loading onto both major histocompatibility complex class I and II molecules. In turn, this enables the synchronous activation of both CD4+ and CD8+ T cell responses against the cognate antigen, thereby bridging the gap between the humoral and cellular branches of the adaptive immune response. Critically, FcRn-driven T cell priming is efficient at very low doses of antigen due to the exquisite sensitivity of the IgG-mediated antigen delivery system through which it operates. FcRn-mediated antigen presentation has important consequences in tissue compartments replete with IgG and serves not only to determine homeostatic immune activation at a variety of sites but also to induce inflammatory responses upon exposure to antigens perceived as foreign. Therapeutically targeting the pathway by which FcRn enables T cell activation in response to IgG IC is thus a highly attractive prospect not only for the treatment of diseases that are driven by immune complexes but also for manipulating local immune responses against defined antigens such as those present during infections and

  10. Antigenic Diversity of Human Sapoviruses

    OpenAIRE

    Hansman, Grant S.; Oka, Tomoichiro; Sakon, Naomi; Takeda, Naokazu

    2007-01-01

    Sapovirus (SaV) is a causative agent of gastroenteritis. On the basis of capsid protein (VP1) nucleotide sequences, SaV can be divided into 5 genogroups (GI?GV), of which the GI, GII, GIV, and GV strains infect humans. SaV is uncultivable, but expression of recombinant VP1 in insect cells results in formation of viruslike particles (VLPs) that are antigenically similar to native SaV. In this study, we newly expressed SaV GII and GIV VLPs to compare genetic and antigenic relationships among al...

  11. Antigenic variation of Plasmodium knowlesi malaria: identification of the variant antigen on infected erythrocytes.

    OpenAIRE

    Howard, R J; Barnwell, J W; Kao, V

    1983-01-01

    Erythrocytes infected with mature asexual stages of Plasmodium knowlesi express a new surface antigen such that rhesus monkey antisera specifically agglutinate these cells. Cloned parasites can express different antigenic variants of this antigen. The variant antigen has been identified by comparison of the surface membrane antigens of a clone and of an antigenic variant of that clone of different agglutination phenotype. After lactoperoxidase labeling, 125I-labeled proteins of Mrs 210,000 an...

  12. Chimeric antigen receptor T-cell therapy for solid tumors

    Directory of Open Access Journals (Sweden)

    Kheng Newick

    2016-01-01

    Full Text Available Chimeric antigen receptor (CAR T cells are engineered constructs composed of synthetic receptors that direct T cells to surface antigens for subsequent elimination. Many CAR constructs are also manufactured with elements that augment T-cell persistence and activity. To date, CAR T cells have demonstrated tremendous success in eradicating hematological malignancies (e.g., CD19 CARs in leukemias. This success is not yet extrapolated to solid tumors, and the reasons for this are being actively investigated. Here in this mini-review, we discuss some of the key hurdles encountered by CAR T cells in the solid tumor microenvironment.

  13. Tissue polypeptide antigen activity in cerebrospinal fluid

    DEFF Research Database (Denmark)

    Bach, F; Söletormos, Georg; Dombernowsky, P

    1991-01-01

    dehydrogenase, or glucose, which showed very low sensitivity (41%, 47%, and 8%, respectively). For quantitative evaluation of treatment for leptomeningeal carcinomatosis, the TPpA level appears to be valuable and superior to CSF cytology, because tumor cells are not always present in CSF samples from patients...

  14. Nasal allergy to avian antigens

    NARCIS (Netherlands)

    R. Gerth van Wijk (Roy); A.W. van Toorenenbergen (Albert); P.H. Dieges

    1987-01-01

    textabstractThis study describes the case of a patient who developed symptoms of rhinoconjunctivitis on exposure to budgerigars and parrots. An IgE‐mediated allergy to budgerigar, parrot and pigeon antigens was demonstrated using both in‐vivo challenge tests (skin and nasal provocation tests) and

  15. 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

  16. Fusion of Epstein-Barr virus nuclear antigen-1-derived glycine-alanine repeat to trans-dominant HIV-1 Gag increases inhibitory activities and survival of transduced cells in vivo.

    Science.gov (United States)

    Hammer, Diana; Wild, Jens; Ludwig, Christine; Asbach, Benedikt; Notka, Frank; Wagner, Ralf

    2008-06-01

    Trans-dominant human immunodeficiency virus type 1 (HIV-1) Gag derivatives have been shown to efficiently inhibit late steps of HIV-1 replication in vitro by interfering with Gag precursor assembly, thus ranking among the interesting candidates for gene therapy approaches. However, efficient antiviral activities of corresponding transgenes are likely to be counteracted in particular by cell-mediated host immune responses toward the transgene-expressing cells. To decrease this potential immunogenicity, a 24-amino acid Gly-Ala (GA) stretch derived from Epstein-Barr virus nuclear antigen-1 (EBNA1) and known to overcome proteasomal degradation was fused to a trans-dominant Gag variant (sgD1). To determine the capacity of this fusion polypeptide to repress viral replication, PM-1 cells were transduced with sgD1 and GAsgD1 transgenes, using retroviral gene transfer. Challenge of stably transfected permissive cell lines with various viral strains indicated that N-terminal GA fusion even enhanced the inhibitory properties of sgD1. Further studies revealed that the GA stretch increased protein stability by blocking proteasomal degradation of Gag proteins. Immunization of BALB/c mice with a DNA vaccine vector expressing sgD1 induced substantial Gag-specific immune responses that were, however, clearly diminished in the presence of GA. Furthermore, recognition of cells expressing the GA-fused transgene by CD8(+) T cells was drastically reduced, both in vitro and in vivo, resulting in prolonged survival of the transduced cells in recipient mice.

  17. Butyrophilin 3A1 binds phosphorylated antigens and stimulates human γδ T cells.

    Science.gov (United States)

    Vavassori, Stefano; Kumar, Anil; Wan, Gan Siok; Ramanjaneyulu, Gundimeda S; Cavallari, Marco; El Daker, Sary; Beddoe, Travis; Theodossis, Alex; Williams, Neal K; Gostick, Emma; Price, David A; Soudamini, Dinish U; Voon, Kong Kien; Olivo, Malini; Rossjohn, Jamie; Mori, Lucia; De Libero, Gennaro

    2013-09-01

    Human T cells that express a T cell antigen receptor (TCR) containing γ-chain variable region 9 and δ-chain variable region 2 (Vγ9Vδ2) recognize phosphorylated prenyl metabolites as antigens in the presence of antigen-presenting cells but independently of major histocompatibility complex (MHC), the MHC class I-related molecule MR1 and antigen-presenting CD1 molecules. Here we used genetic approaches to identify the molecule that binds and presents phosphorylated antigens. We found that the butyrophilin BTN3A1 bound phosphorylated antigens with low affinity, at a stoichiometry of 1:1, and stimulated mouse T cells with transgenic expression of a human Vγ9Vδ2 TCR. The structures of the BTN3A1 distal domain in complex with host- or microbe-derived phosphorylated antigens had an immunoglobulin-like fold in which the antigens bound in a shallow pocket. Soluble Vγ9Vδ2 TCR interacted specifically with BTN3A1-antigen complexes. Accordingly, BTN3A1 represents an antigen-presenting molecule required for the activation of Vγ9Vδ2 T cells.

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

    Directory of Open Access Journals (Sweden)

    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

  19. Persistence of acanthamoeba antigen following acanthamoeba keratitis.

    Science.gov (United States)

    Yang, Y F; Matheson, M; Dart, J K; Cree, I A

    2001-03-01

    To investigate the hypothesis that persistent corneal and scleral inflammation following acanthamoeba keratitis is not always caused by active amoebic infection but can be due to persisting acanthamoebic antigens 24 lamellar corneal biopsy and penetrating keratoplasty specimens were obtained from 14 consecutive patients at various stages of their disease and divided for microscopy and culture. Histological sections were immunostained and screened for the presence of Acanthamoeba cysts by light microscopy. Cultures were carried out using partly homogenised tissues on non-nutrient agar seeded with E coli. Clinical data were obtained retrospectively from the case notes of these patients. Of the 24 specimens, 20 were obtained from eyes that were clinically inflamed at the time of surgery. Acanthamoeba cysts were present in 16 (80%) of these 20 specimens, while only five (25%) were culture positive. Acanthamoeba cysts were found to persist for up to 31 months after antiamoebic treatment. These findings support the hypothesis that Acanthamoeba cysts can remain in corneal tissue for an extended period of time following acanthamoeba keratitis and may cause persistent corneal and scleral inflammation in the absence of active amoebic infection. In view of these findings, prolonged intensive antiamoebic therapy may be inappropriate when the inflammation is due to retained antigen rather than to viable organisms

  20. 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

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

    Science.gov (United States)

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

    2016-07-01

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

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

    Science.gov (United States)

    Abdeen, Sherif H

    2010-01-01

    Immunoregulation is central for successful manipulation of schistosomiasis. Unlike schistosome vaccine development strategies that relied on direct selection of antigens from crude responses leading to selection of mildly protective antigens, the present study tested the utility of selection of potentially protective antigens encompassed rounds of immunoregulation via idiotypic network. Anti-idiotypic antibodies (Ab2) were purified from sera of New Zealand white rabbits multiply immunized with gamma-irradiated cercariae of S. haematobium, using adult worm specific idiotypes (Ab1) purified from sera of subjects resistant to reinfection. Ab2 was used for immunization of C57BL/6 mice and consequences of immunization were monitored before and after challenge infection with S. haematobium. Results showed an increase of splenic T cell expression of intercellular adhesion molecule-1 (ICAM-1) and very late antigen-4 (VLA-4) upon immunization (average % stimulated cells 54.9 vs. 20.4, P ids (Ab3) reactivity against antigens of approximate molecular weight 40, 80 and 160 kDa of adult worms, which were also recognized by Ab1. However, in contrast to Ab1, Ab3 showed no surface binding to 3 hr schistosomula. Strikingly, mice immunized with Ab2 showed strong resistance to challenge infection (approximately 82% reduction in worm burden, P < 0.001). Taking all, this alternative vaccine development strategy appears to filter out non-protective antigens. Indeed Ab3 recognizes much fewer numbers of antigens, which passed through two rounds of immune regulation. These antigens appear to represent a significant proportion of the protective response in the gamma-irradiated cercariae vaccine and human resistance model as well, providing the basis for an alternative vaccine for schistosomiasis.

  3. TISSUE POLYPEPTIDE-SPECIFIC ANTIGEN - A DISCRIMINATIVE PARAMETER BETWEEN PROSTATE-CANCER AND BENIGN PROSTATIC HYPERTROPHY

    NARCIS (Netherlands)

    MARRINK, J; OOSTEROM, R; BONFRER, HMG; SCHRODER, FH; MENSINK, HJA

    1993-01-01

    The serum concentration of the cell proliferation marker TPS (tissue polypeptide-specific antigen) was compared with the tumour marker PSA (prostate specific antigen). PSA was found elevated in 50% of the benign prostatic hypertrophy (BPH) patients, in 88% of the patients with active prostate cancer

  4. Lamivudinbehandling af en hepatitis Bs- antigen-positiv patient med reaktiv artritis

    DEFF Research Database (Denmark)

    Borup, Christian; Siboni, Anders

    2008-01-01

    A 46-year-old man who was HBs antigen positive since childhood had painful talocrural arthritis that was considered re-active to HBs antigen. Lamivudine treatment was started and HBV-DNA disappeared from the blood, and the joint swellings disappeared. HBe antibody disappeared after eight months. ...

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

    DEFF Research Database (Denmark)

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

    1995-01-01

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

  6. IgE production after antigen-specific and cognate activation of HLA-DPw4-restricted T-cell clones, by 78% of randomly selected B-cell donors

    NARCIS (Netherlands)

    Baselmans, PJ; Pollabauer, EM; van Reijsen, FC; Heystek, HC; Hren, A; Stumptner, P; Tilanus, MGJ; Vooijs, WC; Mudde, GC

    The frequency of expression of the MHC class II antigen, HLA-DPw4, in the caucasoid population is approximately 78%, and is unmatched by phenotypic frequencies of other HLA class II molecules. Here we describe three human Der-P1-specific T-cell clones (TCC), restricted by the HLA-DPw4-variant

  7. Peripheral blood lymphocytes from low-grade squamous intraepithelial lesions patients recognize vaccine antigens in the presence of activated dendritic cells, and produced high levels of CD8 + IFNγ + T cells and low levels of IL-2 when induced to proliferate

    Directory of Open Access Journals (Sweden)

    Hernández-Montes Jorge

    2012-05-01

    Full Text Available Abstract Background Most infections with human papillomavirus (HPV are resolved without clinical intervention, but a minority evolves into chronic lesions of distinct grades, including cervical-uterine cancer. It is known that in most cases the immune system mediates elimination of HPV infection. However, the mechanism of immune evasion leading to HPV persistence and development of early cervical lesions is not fully understood. The aim of the present work was to evaluate the potential of peripheral blood leukocytes (PBL from low-grade squamous intraepithelial lesions (LSIL patients to be activated ex-vivo by vaccine antigens, the participation of cytotoxic lymphocytes and regulatory T cells, and to determine the secretion of Th1 and Th2 cytokines mediated by stimulation of T cell receptors. Results We found that PBL from LSIL patients showed a significantly lower proliferation rate to vaccine antigens as compared to that of healthy donors, even though there was not a difference in the presence of antibodies to those antigens in sera from both groups. We did not find differences in either the frequency of CD4 + CD25 + FoxP3+ in PBL, or the levels of IL-4, IL-5 and IL-10 in plasma or conditioned media from PBL incubated with TcR agonists in vitro, between the two groups. However, we detected a lower production of IL-2 and a higher proportion of CD8 + IFNγ + cells in PBL from LSIL patients as compared with PBL from normal donors. We also observed that PBL from patients infected by HPV-16 and −18 were not able to proliferate in the presence of soluble HPV antigens added to the culture; however, a high level of proliferation was attained when these antigens were presented by activated dendritic cells. Conclusions Our results suggest that the immunodeficiency reported in LSIL patients could be due to the inability of specific cytotoxic T lymphocytes that for some unknown reason are present but unable to mount a response when

  8. State of the Art in Tumor Antigen and Biomarker Discovery

    Directory of Open Access Journals (Sweden)

    Patrick Chames

    2011-06-01

    Full Text Available Our knowledge of tumor immunology has resulted in multiple approaches for the treatment of cancer. However, a gap between research of new tumors markers and development of immunotherapy has been established and very few markers exist that can be used for treatment. The challenge is now to discover new targets for active and passive immunotherapy. This review aims at describing recent advances in biomarkers and tumor antigen discovery in terms of antigen nature and localization, and is highlighting the most recent approaches used for their discovery including “omics” technology.

  9. State of the Art in Tumor Antigen and Biomarker Discovery

    Energy Technology Data Exchange (ETDEWEB)

    Even-Desrumeaux, Klervi; Baty, Daniel; Chames, Patrick, E-mail: patrick.chames@inserm.fr [INSERM U624, 163 avenue de Luminy, 13288 Marseille Cedex 09 (France)

    2011-06-09

    Our knowledge of tumor immunology has resulted in multiple approaches for the treatment of cancer. However, a gap between research of new tumors markers and development of immunotherapy has been established and very few markers exist that can be used for treatment. The challenge is now to discover new targets for active and passive immunotherapy. This review aims at describing recent advances in biomarkers and tumor antigen discovery in terms of antigen nature and localization, and is highlighting the most recent approaches used for their discovery including “omics” technology.

  10. Dose and timing requirements for immunogenicity of viral poultry vaccine antigen: investigations of emulsion-based depot function.

    Science.gov (United States)

    Jansen, Theo; Hofmans, Marij P M; Theelen, Marc J G; Manders, Frans G A; Schijns, Virgil E J C

    2007-10-01

    The release requirements for vaccine antigens delivered by adjuvants with presumed depot function are poorly understood. Water-in-oil (W/O) emulsions are routinely used in many poultry vaccines. They strongly activate antibody production, and are regarded as a depot from which antigens are slowly released, resulting in prolonged antigen residence. However, from earlier studies we concluded that W/O adjuvant activity is partly based on the immunostimulatory activity of the oil phase. Here we assess the dose and regimen requirements for viral antigen in immunization experiments in chickens. Three-week-old to 4-week-old White Leghorn chickens were repeatedly injected with inactivated infectious bursal disease virus antigen over 48 days. Our aim was to compare the antibody responses in repeatedly injected animals, receiving fractioned doses of antigen, with the responses in animals receiving only one injection of the full dose of antigen formulated in either a W/O emulsion or in saline. We observed that repeated administration of small amounts of antigen results in a gradual increase of specific humoral immune responses during the immunization regimen. Immunization with a higher first dose evoked an early higher antibody response, which, however, reached a similar plateau level at the end of the regimen. When compared with lower first-dose regimens, a slow decline of serum antibody titre 2 weeks after the end of antigen injections indicated that repeated injection of small doses of antigen indeed mimics the efficacy of depot-forming adjuvants. All regimens of fractioned antigen in saline, however, proved less effective, when compared with a single-dose vaccination of the cumulative amount of antigen formulated in a W/O emulsion. From our data we confirm that W/O emulsions are very effective vaccine vehicles for improving antigen-specific humoral responses in chickens, owing to a combination of antigen residence-prolonging activity and direct immune stimulation.

  11. Generation of monoclonal antibodies against highly conserved antigens.

    Directory of Open Access Journals (Sweden)

    Hongzhe Zhou

    Full Text Available BACKGROUND: Therapeutic antibody development is one of the fastest growing areas of the pharmaceutical industry. Generating high-quality monoclonal antibodies against a given therapeutic target is very crucial for the success of the drug development. However, due to immune tolerance, some proteins that are highly conserved between mice and humans are not very immunogenic in mice, making it difficult to generate antibodies using a conventional approach. METHODOLOGY/PRINCIPAL FINDINGS: In this report, the impaired immune tolerance of NZB/W mice was exploited to generate monoclonal antibodies against highly conserved or self-antigens. Using two highly conserved human antigens (MIF and HMGB1 and one mouse self-antigen (TNF-alpha as examples, we demonstrate here that multiple clones of high affinity, highly specific antibodies with desired biological activities can be generated, using the NZB/W mouse as the immunization host and a T cell-specific tag fused to a recombinant antigen to stimulate the immune system. CONCLUSIONS/SIGNIFICANCE: We developed an efficient and universal method for generating surrogate or therapeutic antibodies against "difficult antigens" to facilitate the development of therapeutic antibodies.

  12. Engineering Chimeric Antigen Receptor T cells to Treat Glioblastoma.

    Science.gov (United States)

    Choi, Bryan D; O'Rourke, Donald M; Maus, Marcela V

    2017-08-01

    Immunotherapy has emerged as a promising strategy for glioblastoma (GBM), a disease that remains universally fatal despite currently available standard-of-care. Adoptive T cell therapy has been shown to produce potent antitumor immunity while obviating the need for traditional antigen presentation and primary immune responses. Chimeric antigen receptors (CARs) are specialized molecules that can be expressed on the surface of T cells allowing for redirected cytotoxicity against tumor antigens of interest. To date, the application of CAR T cells for GBM has been relatively limited, in large part due to a dearth of well-described tumor specific antigens that are both homogenously and frequently expressed. A mutated version of the epidermal growth factor receptor, EGFRvIII, is a constitutively activated tyrosine kinase that is expressed on the surface of GBM and other common neoplasms, but completely absent from all normal tissues. We have recently generated CAR T cells directed against EGFRvIII and reported results from a Phase I clinical trial investigating this platform in patients with EGFRvIII-expressing GBM. Our study showed that despite conventional notions of central nervous system "immune-privilege," EGFRvIII CAR T cells trafficked to intracerebral tumors, leading to successful targeting and eradication of this antigen in the brain. Here, we review our experience with EGFRvIII CAR T cells and highlight important considerations for the clinical translation of this therapy in patients with GBM.

  13. How T lymphocytes recognize lipid antigens.

    Science.gov (United States)

    De Libero, Gennaro; Mori, Lucia

    2006-10-09

    Recognition of lipid antigens by T lymphocytes is well established. Lipids are recognized by T cells when presented in association with CD1 antigen-presenting molecules. Both microbial and self lipids stimulate specific T lymphocytes, thus participating in immune reactions during infections and autoimmune diseases. The immune system uses a variety of strategies to solubilise lipid antigens, to facilitate their internalization, processing, and loading on CD1 molecules. Recent studies in the field of lipid antigen presentation have revealed new mechanisms which allow the immune system to sense lipids as stimulatory antigens.

  14. Binding of hydrophobic antigens to surfaces

    DEFF Research Database (Denmark)

    2017-01-01

    A first aspect of the present invention is a method of detecting antibodies comprising the steps of: i) providing a first group of beads comprising a surface modified with C1-C10 alkyl groups comprising amine, ammonium, ether and/or hydroxyl groups, ii) contacting said first group of beads...... with a first hydrophobic antigen to provide a first group of bead-antigen conjugates by adsorption of the first hydrophobic antigen on the first group of beads, iii) isolating said bead- antigen conjugates, iv) contacting said bead-antigen conjugates with a sample to bind antibodies therein to provide bead...

  15. Trafficking of B cell antigen in lymph nodes

    DEFF Research Database (Denmark)

    Gonzalez, Santiago F.; Degn, Søren Egedal; Pitcher, Lisa A.

    2011-01-01

    ). The experimental demonstration by Nossal & Lederberg ( 3 ) that B lymphocytes bear receptors for a single antigen raised the central question of where B lymphocytes encounter antigen. This question has remained mostly unanswered until recently. Advances in techniques such as multiphoton intravital microscopy ( 4......The clonal selection theory first proposed by Macfarlane Burnet is a cornerstone of immunology ( 1 ). At the time, it revolutionized the thinking of immunologists because it provided a simple explanation for lymphocyte specificity, immunological memory, and elimination of self-reactive clones ( 2......, 5 ) have provided new insights into the trafficking of B cells and their antigen. In this review, we summarize these advances in the context of our current view of B cell circulation and activation....

  16. Artificial Loading of ASC Specks with Cytosolic Antigens.

    Directory of Open Access Journals (Sweden)

    Ali Can Sahillioğlu

    Full Text Available Inflammasome complexes form upon interaction of Nod Like Receptor (NLR proteins with pathogen associated molecular patterns (PAPMS inside the cytosol. Stimulation of a subset of inflammasome receptors including NLRP3, NLRC4 and AIM2 triggers formation of the micrometer-sized spherical supramolecular complex called the ASC speck. The ASC speck is thought to be the platform of inflammasome activity, but the reason why a supramolecular complex is preferred against oligomeric platforms remains elusive. We observed that a set of cytosolic proteins, including the model antigen ovalbumin, tend to co-aggregate on the ASC speck. We suggest that co-aggregation of antigenic proteins on the ASC speck during intracellular infection might be instrumental in antigen presentation.

  17. 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.

  18. Immune responses to chlamydial antigens in humans.

    Science.gov (United States)

    Hanna, L; Kerlan, R; Senyk, G; Stites, D P; Juster, R P; Jawetz, E

    1982-01-01

    Antibody titer, lymphocyte stimulation and leukocyte migration inhibition with chlamydial antigens were determined repeatedly over many months on human subjects. The volunteers were retrospectively placed into four groups on the basis of clinical, laboratory and epidemiologic criteria. Group A consisted of persons with proven or probable chlamydial infection, including an illness confirmed by chlamydial isolation or seroconversion, or a clinically compatible illness with positive serologic results. Group B were sexual partners or close contacts of group A individuals. Group C were laboratory workers with prolonged exposure to viable chlamydiae or their antigens. Group D included persons of comparable age as those in groups A and B, but lacking a history of symptomatic chlamydial infection or of contact with chlamydiae. Individual cases illustrated the rise of antibody and some cell mediated immunity reactions (CMI) with active chlamydial infection. By contrast, laboratory exposure resulted in elevation of CMI but not of antibody. Statistical analysis of the results in 46 volunteers tested repeatedly indicated a strong association of specific antibody with lymphocyte stimulation, but not with leukocyte migration inhibition. Regression analysis suggested that the type of exposure markedly influenced the relationship between antibody and lymphocyte stimulation. Measurement of immunotype-specific antibody titer by microimmunofluorescence (or an equally sensitive method) remains the best laboratory indicator of past chlamydial infection. Neither antibody nor CMI can, as yet, be definitely related to resistance to re-infection in humans.

  19. 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.

  20. Presentation of lipid antigens to T cells.

    Science.gov (United States)

    Mori, Lucia; De Libero, Gennaro

    2008-04-15

    T cells specific for lipid antigens participate in regulation of the immune response during infections, tumor immunosurveillance, allergy and autoimmune diseases. T cells recognize lipid antigens as complexes formed with CD1 antigen-presenting molecules, thus resembling recognition of MHC-peptide complexes. The biophysical properties of lipids impose unique mechanisms for their delivery, internalization into antigen-presenting cells, membrane trafficking, processing, and loading of CD1 molecules. Each of these steps is controlled at molecular and celular levels and determines lipid immunogenicity. Lipid antigens may derive from microbes and from the cellular metabolism, thus allowing the immune system to survey a large repertoire of immunogenic molecules. Recognition of lipid antigens facilitates the detection of infectious agents and the initiation of responses involved in immunoregulation and autoimmunity. This review focuses on the presentation mechanisms and specific recognition of self and bacterial lipid antigens and discusses the important open issues.

  1. CARbodies: Human Antibodies Against Cell Surface Tumor Antigens Selected From Repertoires Displayed on T Cell Chimeric Antigen Receptors

    OpenAIRE

    Alonso-Camino, Vanesa; Sánchez-Martín, David; Compte, Marta; Nuñez-Prado, Natalia; Diaz, Rosa M; Vile, Richard; Alvarez-Vallina, Luis

    2013-01-01

    A human single-chain variable fragment (scFv) antibody library was expressed on the surface of human T cells after transduction with lentiviral vectors (LVs). The repertoire was fused to a first-generation T cell receptor ζ (TCRζ)-based chimeric antigen receptor (CAR). We used this library to isolate antibodies termed CARbodies that recognize antigens expressed on the tumor cell surface in a proof-of-principle system. After three rounds of activation-selection there was a clear repertoire res...

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

    Directory of Open Access Journals (Sweden)

    Tarlan Mamedov

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

  3. Risk-stratification based on magnetic resonance imaging and prostate-specific antigen density may reduce unnecessary follow-up biopsy procedures in men on active surveillance for low-risk prostate cancer.

    Science.gov (United States)

    Alberts, Arnout R; Roobol, Monique J; Drost, Frank-Jan H; van Leenders, Geert J; Bokhorst, Leonard P; Bangma, Chris H; Schoots, Ivo G

    2017-10-01

    To assess the value of risk-stratification based on magnetic resonance imaging (MRI) and prostate-specific antigen density (PSA-D) in reducing unnecessary biopsies without missing Gleason pattern 4 prostate cancer in men on active surveillance (AS). In all, 210 men on AS with Gleason score 3 + 3 prostate cancer received a first MRI and if indicated [Prostate Imaging Reporting and Data System (PI-RADS) score ≥3] targeted biopsy (TBx) using MRI-transrectal ultrasonography (TRUS) fusion. The MRI was performed 3 months after diagnosis (group A: n = 97), at confirmatory biopsy (group B: n = 39) or at surveillance biopsy after one or more repeat TRUS-guided systematic biopsies (TRUS-Bx) (group C: n = 74). The primary outcome was upgrading to Gleason score ≥3 + 4 prostate cancer based on MRI ± TBx in groups A, B and C. Biopsy outcomes were stratified for the overall PI-RADS score and PSA-D to identify a subgroup of men in whom a biopsy could have been avoided as no Gleason score upgrading was detected. In all, 134/210 (64%) men had a positive MRI and 51/210 (24%) men had Gleason score upgrading based on MRI-TBx. The percentage of Gleason score upgrading based on MRI-TBx was 23% (22/97), 23% (9/39) and 27% (20/74) in respectively groups A, B and C. Additional Gleason score upgrading detected by TRUS-Bx occurred in 8% (3/39) of men in group B and 6% (1/17) of men who received TRUS-Bx in group C. No Gleason score upgrading was detected by MRI-TBx in men with a PI-RADS score of 3 and a PSA-D of PI-RADS score of 1-3 and a PSA-D of PI-RADS score of 1-3 and PSA-D of PI-RADS and PSA-D may reduce unnecessary follow-up biopsy procedures in men on AS. © 2017 The Authors BJU International © 2017 BJU International Published by John Wiley & Sons Ltd.

  4. Evaluation of Intracellular Signaling Downstream Chimeric Antigen Receptors.

    Directory of Open Access Journals (Sweden)

    Hannah Karlsson

    Full Text Available CD19-targeting CAR T cells have shown potency in clinical trials targeting B cell leukemia. Although mainly second generation (2G CARs carrying CD28 or 4-1BB have been investigated in patients, preclinical studies suggest that third generation (3G CARs with both CD28 and 4-1BB have enhanced capacity. However, little is known about the intracellular signaling pathways downstream of CARs. In the present work, we have analyzed the signaling capacity post antigen stimulation in both 2G and 3G CARs. 3G CAR T cells expanded better than 2G CAR T cells upon repeated stimulation with IL-2 and autologous B cells. An antigen-driven accumulation of CAR+ cells was evident post antigen stimulation. The cytotoxicity of both 2G and 3G CAR T cells was maintained by repeated stimulation. The phosphorylation status of intracellular signaling proteins post antigen stimulation showed that 3G CAR T cells had a higher activation status than 2G. Several proteins involved in signaling downstream the TCR were activated, as were proteins involved in the cell cycle, cell adhesion and exocytosis. In conclusion, 3G CAR T cells had a higher degree of intracellular signaling activity than 2G CARs which may explain the increased proliferative capacity seen in 3G CAR T cells. The study also indicates that there may be other signaling pathways to consider when designing or evaluating new generations of CARs.

  5. BIOCHEMICAL STUDIES ON SO-CALLED SYPHILIS ANTIGEN

    Science.gov (United States)

    Noguchi, Hideyo; Bronfenbrenner, J.

    1911-01-01

    The liver tissues of man and certain animals (dogs, rabbits, guinea pigs, etc.) yield, upon alcoholic extraction, various substances which may be divided by their physical and chemical properties into several groups. While many substances are present in the alcoholic extract, the ones possessing antigenic properties are comparatively few. The latter are responsible for the antigenic properties exhibited by the whole alcoholic extract. The substances extracted with alcohol were fractionated into the following four groups. (a) Substances Insoluble in Ether and Hot Alcohol.—These are chiefly proteins and salts. The proteins are probably the minute particles of larger molecules held in apparent suspension in alcohol until all other substances are removed. The water extracted from the tissues and admixed with alcohol is also an essential factor in extracting these particles in an alcoholic solution. The salts present are the usual physiological constituents of the liver, notably, sodium chloride. The quantity of these substances extracted with alcohol varies greatly with different specimens. Biologically considered, they are neither markedly hemolytic nor anticomplementary and possess no antigenic property for the Wassermann reaction. It is important, however, to note that the proteins bind complement when mixed with certain active human sera. For this reason a preparation of antigen containing this group of substances is unsuitable for use in combination with an active serum, and should, therefore, be rejected. (b) Substances Insoluble in Ether and Soluble in Hot Alcohol.—This group contains soaps, cleavage products of proteins, and small amounts of the bile salts. Soaps and bile salts are very strongly hemolytic and are absolutely unfit for use as antigen. Moreover, their antigenic properties are very slight. It is best to eliminate this group of substances from the preparation of antigen. The quantity of the substances of this group extracted from different

  6. Oligopeptide antigens of the angiotensin lineage compete for presentation by paraformaldehyde-treated accessory cells to T cells

    DEFF Research Database (Denmark)

    Buus, S; Werdelin, O

    1986-01-01

    The heptapeptide antigen angiotensin III can be presented to guinea pig T cells by paraformaldehyde-treated antigen-presenting cells, which are incapable of processing antigens and presumably cannot even ingest them. We demonstrate here that the decapeptide angiotensin I can outcompete angiotensi...... of competition between antigens for presentation; but since they presumably are active also in untreated cells, they may play a physiologic role in the normal immune response.......The heptapeptide antigen angiotensin III can be presented to guinea pig T cells by paraformaldehyde-treated antigen-presenting cells, which are incapable of processing antigens and presumably cannot even ingest them. We demonstrate here that the decapeptide angiotensin I can outcompete angiotensin...

  7. Epstein-Barr virus (EBV) glycoprotein gp350 expressed on transfected cells resistant to natural killer cell activity serves as a target antigen for EBV-specific antibody-dependent cellular cytotoxicity.

    OpenAIRE

    Khyatti, M.; Patel, P C; Stefanescu, I.; Menezes, J

    1991-01-01

    Cell surface-associated viral glycoproteins are thought to play a major role as target antigens in cellular cytotoxicity and antiviral immunosurveillance. One such glycoprotein is the Epstein-Barr virus (EBV)-encoded glycoprotein 350 (gp350), which is expressed on both virion envelope and EBV producer cells and carries the virus attachment protein moiety. Although it is known that some antibodies to gp350 can neutralize the virus, the role of this glycoprotein in EBV-specific cellular cytotox...

  8. Latency-Associated Nuclear Antigen Encoded by Kaposi's Sarcoma-Associated Herpesvirus Interacts with Tat and Activates the Long Terminal Repeat of Human Immunodeficiency Virus Type 1 in Human Cells

    OpenAIRE

    Hyun, Teresa S.; Subramanian, Chitra; Cotter, Murray A.; Robert A. Thomas; Robertson, Erle S.

    2001-01-01

    The latency-associated nuclear antigen (LANA) is constitutively expressed in cells infected with the Kaposi's sarcoma (KS) herpesvirus (KSHV), also referred to as human herpesvirus 8. KSHV is tightly associated with body cavity-based lymphomas (BCBLs) in immunocompromised patients infected with human immunodeficiency virus (HIV). LANA, encoded by open reading frame 73 of KSHV, is one of a small subset of proteins expressed during latent infection and was shown to be important in tethering the...

  9. 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

  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. THE SEARCH OF OPTIMAL COMBINATION OF ANTIGENS FOR SEROLOGICAL DIAGNOSTICS OF TUBERCULOSIS

    Directory of Open Access Journals (Sweden)

    E. V. Vasilyeva

    2013-01-01

    Full Text Available Abstract. The four chimeric recombinant antigens CBD-CFP10, CBD-ESAT6, ESAT6-CFP10 and CBD-P38 contained aminoacid sequences of full-size proteins ESAT6, CFP10 and matured protein P38 of M. tuberculosis, joined with aminoacid sequences of cellulose bind domain of endogluconase A (CBD from Cellumonas fimi have been obtained by gene engineering methods. Recombinant proteins were purified by affine chromatography in column with Ni-NTA-sepharose 6В-CL and as PPDN-3 were used for detection of their antigenic activity in indirect ELISA for TB serological diagnostics. The sera from patients with lung tuberculosis (n = 321, from persons who had professional contacts with TB patients (n = 42, from healthy blood donors (n = 366 and from patients with lung diseases of non-TB etiology were tested. It was detected that there was positive correlation between antibodies level for all studied antigens compared by pair. It has been demonstrated that although antigens were different by antigenic and immunobiological characteristics they add each other in the content of antigenic diagnostics compositions. Thus, all these antigens can be used in the test kits for serological diagnostics of TB. Using of these antigens will allow to detect persons infected by TB and patients with active tuberculosis. 

  12. Oncogenic cancer/testis antigens

    DEFF Research Database (Denmark)

    Gjerstorff, Morten F; Andersen, Mads H; Ditzel, Henrik J

    2015-01-01

    Recent developments have set the stage for immunotherapy as a supplement to conventional cancer treatment. Consequently, a significant effort is required to further improve efficacy and specificity, particularly the identification of optimal therapeutic targets for clinical testing. Cancer....../testis antigens are immunogenic, highly cancer-specific, and frequently expressed in various types of cancer, which make them promising candidate targets for cancer immunotherapy, including cancer vaccination and adoptive T-cell transfer with chimeric T-cell receptors. Our current understanding of tumor...... or novel immunotherapies such as checkpoint blockade or adoptive transfer, represents a highly synergistic approach with the potential to improve patient survival....

  13. Surface EMG signals in very late-stage of Duchenne muscular dystrophy: a case study

    NARCIS (Netherlands)

    Lobo-Prat, J.; Janssen, M.M.H.P.; Koopman, B.; Stienen, A.H.A.; Groot, I.J.M. de

    2017-01-01

    BACKGROUND: Robotic arm supports aim at improving the quality of life for adults with Duchenne muscular dystrophy (DMD) by augmenting their residual functional abilities. A critical component of robotic arm supports is the control interface, as is it responsible for the human-machine interaction.

  14. A very late viral protein triggers the lytic release of SV40.

    Directory of Open Access Journals (Sweden)

    Robert Daniels

    2007-07-01

    Full Text Available How nonenveloped viruses such as simian virus 40 (SV40 trigger the lytic release of their progeny is poorly understood. Here, we demonstrate that SV40 expresses a novel later protein termed VP4 that triggers the timely lytic release of its progeny. Like VP3, VP4 synthesis initiates from a downstream AUG start codon within the VP2 transcript and localizes to the nucleus. However, VP4 expression occurs approximately 24 h later at a time that coincides with cell lysis, and it is not incorporated into mature virions. Mutation of the VP4 initiation codon from the SV40 genome delayed lysis by 2 d and reduced infectious particle release. Furthermore, the co-expression of VP4 and VP3, but not their individual expression, recapitulated cell lysis in bacteria. Thus, SV40 regulates its life cycle by the later temporal expression of VP4, which results in cell lysis and enables the 50-nm virus to exit the cell. This study also demonstrates how viruses can generate multiple proteins with diverse functions and localizations from a single reading frame.

  15. Very late effects of dual chamber pacing therapy for obstructive hypertrophic cardiomyopathy.

    Science.gov (United States)

    Lucon, Adrien; Palud, Laurent; Pavin, Dominique; Donal, Erwan; Behar, Nathalie; Leclercq, Christophe; Mabo, Philippe; Daubert, Jean-Claude

    2013-01-01

    The very long-term effects of dual chamber pacing as a primary treatment for hypertrophic obstructive cardiomyopathy (HOCM) are poorly known and controversial. To examine the intermediate- and long-term clinical and haemodynamic effects of permanent dual chamber pacing in patients presenting with HOCM. Between 1991 and 2007, 51 patients (mean age 59 ± 14 years) presenting with HOCM and New York Heart Association (NYHA) functional class ≥ II despite optimal medical therapy underwent implantation of DDD pacemakers with or without a defibrillator and were followed for 11.5 years (range 0.4-21.8 years). During follow-up, no patient underwent myectomy or septal alcohol ablation. NYHA functional class and other disease manifestations decreased significantly over 1-2 years of follow-up and remained stable thereafter. The left intraventricular (LV) gradient decreased by a mean of 78% over 1-2 years, reaching 89% at end of follow-up, along with disappearance of systolic anterior motion of the mitral valve. Mean LV ejection fraction decreased from a mean of 64 ± 8% before pacing to 56 ± 9% at end of follow-up (P=0.05), while LV end-diastolic diameter did not change significantly. The 5- and 10-year actuarial survival rates were 90% and 65%, respectively. Among 22 deaths, 10 were due to cardiovascular and 12 to non-cardiovascular causes; two patients underwent cardiac transplantation after 8 and 13 years of DDD pacing, respectively. In this sample of patients with HOCM, DDD pacing alleviated symptoms and improved haemodynamic function over the very long term. The merits of this treatment should be revisited in a controlled trial. Copyright © 2013. Published by Elsevier Masson SAS.

  16. Megaduodenum in a 59-year-old man: a very late postoperative complication after duodenal atresia.

    Science.gov (United States)

    Rueff, Jessica; Söllner, Oliver; Zuber, Markus; Weixler, Benjamin

    2018-01-18

    Intestinal malformations are common defects of the newborn, treated in experienced centres. Reports on long-term follow-up and associated complications are scarce, possibly leading to misinterpretation of clinical signs and symptoms in adulthood. To prevent treatment errors, it is important that physicians are aware of long-term complications of intestinal malformations. © BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  17. Surface EMG signals in very late-stage of Duchenne muscular dystrophy : A case study

    NARCIS (Netherlands)

    Lobo Prat, J.; Janssen, Mariska M.H.P.; Koopman, Bart F.J.M.; Stienen, Arno H.A.; De Groot, Imelda J.M.

    2017-01-01

    Background: Robotic arm supports aim at improving the quality of life for adults with Duchenne muscular dystrophy (DMD) by augmenting their residual functional abilities. A critical component of robotic arm supports is the control interface, as is it responsible for the human-machine interaction.

  18. [Th2 differentiation features of Mycobacterium tuberculosis heat resistant antigen-activated human γδT cells and the regulation of transcription factor T-bet/GATA-3 on differentiation].

    Science.gov (United States)

    Zhu, Anyou; Lv, Hezuo; Zhang, Lunjun; Hu, Jianguo; Wang, Fengchao; Li, Baiqing

    2015-01-01

    To investigate Th2 differentiation features of Mycobacterium tuberculosis heat resistant antigens (MTB-HAg)-activated human γδT cells and the regulation of transcription factor T-box expression in T cells (T-bet) and GATA-binding protein 3 (GATA-3) on differentiation. Peripheral blood mononuclear cells (PBMCs) were stimulated with MTB-HAg to generate MTB-HAg-activated T cells (MTBAT) and expanded in the neutral condition or Th2 polarizing condition. After restimulation for 6 hours with phorbol myristate acetate (PMA, 10 ng/mL), ionomycin (500 ng/mL) and monensin (2.5 μmol/L), intracellular cytokines (IFN-γ, IL-4) of γδT cells and αβT cells among MTBAT were detected by four-color fluorescence mAb staining combined with flow cytometry. The highly purified γδT cells and CD4⁺ T cells were sorted by flow cytometer from MTBAT that were cultured in neutral and Th2 polarizing conditions for 28 days. The expressions of T-bet and GATA-3 mRNA in purified γδT cells and CD4⁺ T cells were determined by reverse transcription PCR (RT-PCR) technique. γδT cells among MTBAT cultured in the neutral or Th2 polarizing condition predominantly produced IFN-γ, whereas the percentage of IFN-γ⁺ αβT cells significantly decreased in the Th2 polarizing condition as the culture time went by. Compared with the neutral condition, Th0 type (IFN-γ⁺ IL-4⁺) γδT cells significantly increased, and Th2 type (IFN-γ⁻ IL-4⁺) αβT cells also significantly increased in the Th2 polarizing condition. RT-PCR showed that mRNA expression of T-bet was still at a high level in γδT cells that were expanded in the Th2 polarizing condition, but at a low level in Th2 polarized CD4⁺ T cells. Moreover, the mRNA expressions of GATA-3 in both Th2 polarized γδT cells and CD4⁺T cells were up-regulated. In the Th2 polarizing condition, the majority of γδT cells in MTBAT still remained Th1 profile, whereas the portion of γδT cells differentiated into Th0 type cells. Both

  19. Nanoscale artificial antigen presenting cells for T cell immunotherapy.

    Science.gov (United States)

    Perica, Karlo; De León Medero, Andrés; Durai, Malarvizhi; Chiu, Yen Ling; Bieler, Joan Glick; Sibener, Leah; Niemöller, Michaela; Assenmacher, Mario; Richter, Anne; Edidin, Michael; Oelke, Mathias; Schneck, Jonathan

    2014-01-01

    Artificial antigen presenting cells (aAPC), which deliver stimulatory signals to cytotoxic lymphocytes, are a powerful tool for both adoptive and active immunotherapy. Thus far, aAPC have been synthesized by coupling T cell activating proteins such as CD3 or MHC-peptide to micron-sized beads. Nanoscale platforms have different trafficking and biophysical interaction properties and may allow development of new immunotherapeutic strategies. We therefore manufactured aAPC based on two types of nanoscale particle platforms: biocompatible iron-dextran paramagnetic particles (50-100 nm in diameter) and avidin-coated quantum dot nanocrystals (~30 nm). Nanoscale aAPC induced antigen-specific T cell proliferation from mouse splenocytes and human peripheral blood T cells. When injected in vivo, both iron-dextran particles and quantum dot nanocrystals enhanced tumor rejection in a subcutaneous mouse melanoma model. This is the first description of nanoscale aAPC that induce antigen-specific T cell proliferation in vitro and lead to effective T cell stimulation and inhibition of tumor growth in vivo. Artifical antigen presenting cells could revolutionize the field of cancer-directed immunotherapy. This team of investigators have manufactured two types of nanoscale particle platform-based aAPCs and demonstrates that both iron-dextran particles and quantum dot nanocrystals enhance tumor rejection in a melanoma model, providing the first description of nanoscale aAPCs that lead to effective T cell stimulation and inhibition of tumor growth. © 2013.

  20. Regulatory role of pro-Th1 and pro-Th2 cytokines in modulating the activity of Th1 and Th2 cells when B cell and macrophages are used as antigen presenting cells

    Directory of Open Access Journals (Sweden)

    Agrewala Javed N

    2006-08-01

    Full Text Available Abstract Background Presence of antigen presenting cells, expression of costimulatory molecules, the strength of first signal and cytokine milieu are quite important in influencing the reactivation of differentiated Th1 and Th2 cells. Results In the present study, we have analyzed the concerted action of pro-Th1 and pro-Th2 cytokines in the presence of B cells, peritoneal and splenic macrophages as antigen presenting cells and varied concentration of first (anti-CD3 Ab and second (B7-1 transfectant signals on the proliferation and cytokine secretion by Th1 and Th2 cells. Interesting observations were made that IFN-γ significantly augmented the secretion of IL-4 by Th2 cells when either B cells or splenic or peritoneal macrophages were used as APC. Further, IFN-γ significantly inhibited the proliferation of Th1 cells only in the presence of peritoneal macrophages. We have also observed that B cells could significantly respond to cytokines to further enhance the proliferation and cytokine release by Th1 and Th2 cells. But not much effect on addition of exogenous cytokines IL-1, IL-4, IL-5, IL-12 was observed on the proliferation of Th1 and Th2 cells in the presence of macrophages. In contrast, both IFN-γ and IL-2 significantly enhanced the production of IL-4 and IL-5 respectively, by Th2 cells in presence of B cells, splenic and peritoneal macrophages. Another important observation was that the addition of B7-1 transfectants in the cultures, which were stimulated with low dose of anti-CD3 Ab significantly, enhanced the proliferation and cytokine secretion. Conclusion This study indicates involvement of different type of APCs, cytokine milieu, dose of first and second signals in a concerted manner in the outcome of the immune response. The significance of this study is that the immunization with antigen along with costimulatory molecules may significantly reduce the dose of antigen and can generate better immune response than antigen alone.

  1. 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.

  2. Antigen mapping in hereditary epidermolysis bullosa

    Directory of Open Access Journals (Sweden)

    Srinivas C

    1998-01-01

    Full Text Available Standard immunofluorescence tests are not positive in the various inherited epidermolysis bullosa (EB. Using antibodies to known antigens present in the basement membrane zone, antigen mapping can be done by immuno fluorescence, to determine the level of blistering and establish the diagnosis. We report three cases of junctional EB and one case of dystrophic EB in whom the diagnosis was confirmed by antigen mapping.

  3. Purification and properties of extracellular polysaccharide (EPS) antigens produced by different mould species.

    Science.gov (United States)

    Notermans, S; Wieten, G; Engel, H W; Rombouts, F M; Hoogerhout, P; van Boom, J H

    1987-02-01

    Extracellular polysaccharide (EPS) antigens produced by different mould species were purified and partially characterized. Purification included (NH4)2SO4 treatment, Sepharose CL-4B column chromatography and Con A-sepharose chromatography. The EPS of Penicillium digitatum, Mucor racemosus and Cladosporium cladosporioides showed high antigenic capacities. Immunologically the EPS were partially genus-specific, but cross-reactivity was observed. The EPS antigens produced by species of Penicillium, Aspergillus repens and Geotrichum candidum lost their immunological activity upon heating (100 degrees C) at pH 1.8, while the EPS antigen of M. racemosus, Rhizopus oligosporus and C. cladosporioides were stable under the same conditions. The dominant monosaccharides present in the EPS antigen were mannose, galactose and glucose. The EPS obtained from cultures of M. racemosus and R. oligosporus also contained rhamnose. In the EPS produced by Penicillium spp. and A. repens the galactose residues were determined to be immunodominant.

  4. Enhanced expression of beta2-microglobulin and HLA antigens on human lymphoid cells by interferon

    DEFF Research Database (Denmark)

    Heron, I; Hokland, M; Berg, K

    1979-01-01

    Mononuclear cells from the blood of healthy normal humans were kept in cultures under nonstimulating conditions for 16 hr in the presence or absence of human interferon. The relative quantities of HLA antigens and beta(2)-microglobulin on the cultured cells were determined by quantitative...... immunofluorescence (fluorescence-activated cell sorter) and by the capacity of cells to absorb out cytotoxic antibodies against the relevant antigens. Interferons of different origin and purities enhanced the expression of HLA antigens and beta(2)-microglobulins, whereas membrane immunoglobulins and antigens...... recognized by antiserum raised against human brain and T cells were the same on interferon-treated and control cells. Similar interferon effects were observed on an Epstein-Barrvirus-negative Burkitt lymphoma cell line. The enhanced expression of histocompatibility antigen subsequent to intereferon treatment...

  5. A Safe Bacterial Microsyringe for In Vivo Antigen Delivery and Immunotherapy

    Science.gov (United States)

    Le Gouëllec, Audrey; Chauchet, Xavier; Laurin, David; Aspord, Caroline; Verove, Julien; Wang, Yan; Genestet, Charlotte; Trocme, Candice; Ahmadi, Mitra; Martin, Sandrine; Broisat, Alexis; Cretin, François; Ghezzi, Catherine; Polack, Benoit; Plumas, Joël; Toussaint, Bertrand

    2013-01-01

    The industrial development of active immunotherapy based on live-attenuated bacterial vectors has matured. We developed a microsyringe for antigen delivery based on the type III secretion system (T3SS) of P. aeruginosa. We applied the “killed but metabolically active” (KBMA) attenuation strategy to make this bacterial vector suitable for human use. We demonstrate that attenuated P. aeruginosa has the potential to deliver antigens to human antigen-presenting cells in vitro via T3SS with considerable attenuated cytotoxicity as compared with the wild-type vector. In a mouse model of cancer, we demonstrate that this KBMA strain, which cannot replicate in its host, efficiently disseminates into lymphoid organs and delivers its heterologous antigen. The attenuated strain effectively induces a cellular immune response to the cancerous cells while lowering the systemic inflammatory response. Hence, a KBMA P. aeruginosa microsyringe is an efficient and safe tool for in vivo antigen delivery. PMID:23531551

  6. Characterisation of centromere (kinetochore) antigen reactive with sera of patients with a scleroderma variant (CREST syndrome).

    Science.gov (United States)

    Nishikai, M; Okano, Y; Yamashita, H; Watanabe, M

    1984-01-01

    Anticentromere (kinetochore) antibody is the marker antibody in CREST syndrome, but the precise molecular composition of the partner antigen has been poorly defined. This report describes for the first time a procedure for the successful extraction and biochemical characterisation of the centromere antigen molecule. The centromere antigen was extracted with 4M NaCl solution. The molecular weight of the partner antigen of the centromere antibody was determined to be 70 000 daltons by the SDS-PAGE and immunoblotting methods. A Sephacryl S-300 column experiment confirmed these results. Centromere antigenic activity was preserved at pHs between 3 and 11 and was resistant to three enzymes, trypsin, RNase, and DNase. Images PMID:6524984

  7. Distribution and Characterization of Antigens Found in Subcellular Fractions of African Trypanosomes.

    Science.gov (United States)

    1981-08-01

    Recent studies have been reported for Trypanosoma cruzi (Gonzalez Cappa et al, 1980) but were mainly concerned with establishing the antigenicity of...fractions in the presence of 0.5% Triton X-100 10.1% Zwittergent. For both A and B anti Pb IgG was used. (A) Demonstration of acid phosphatase activity ...demonstration of cysosomal proteolytic activity . Nature 224:279-281. Bawden, M.P. 1975. Whence comes Trypanosoma lewisi antigen which induces ablastic antibody

  8. Imaging the Interactions Between B Cells and Antigen-Presenting Cells.

    Science.gov (United States)

    Wang, Jia C; Bolger-Munro, Madison; Gold, Michael R

    2018-01-01

    In vivo, B cells are often activated by antigens that are displayed on the surface of antigen-presenting cells (APCs). Binding of membrane-associated antigens to the B cell receptor (BCR) causes rapid cytoskeleton-dependent changes in the spatial organization of the BCR and other B cell membrane proteins, leading to the formation of an immune synapse. This process has been modeled using antigens attached to artificial planar lipid bilayers or to plasma membrane sheets. As a more physiological system for studying B cell-APC interactions, we have expressed model antigens in easily transfected adherent cell lines such as Cos-7 cells. The model antigens that we have used are a transmembrane form of a single-chain anti-Igκ antibody and a transmembrane form of hen egg lysozyme that is fused to a fluorescent protein. This has allowed us to study multiple aspects of B cell immune synapse formation including cytoskeletal reorganization, BCR microcluster coalescence, BCR-mediated antigen gathering, and BCR signaling. Here, we provide protocols for expressing these model antigens on the surface of Cos-7 cells, transfecting B cells with siRNAs or with plasmids encoding fluorescent proteins, using fixed cell and live cell fluorescence microscopy to image B cell-APC interactions, and quantifying APC-induced changes in BCR spatial organization and signaling.

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

    Directory of Open Access Journals (Sweden)

    Yi Liu

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

  10. A Review of Intra- and Extracellular Antigen Delivery Systems for Virus Vaccines of Finfish

    Directory of Open Access Journals (Sweden)

    Hetron Mweemba Munang’andu

    2015-01-01

    Full Text Available Vaccine efficacy in aquaculture has for a long time depended on evaluating relative percent survival and antibody responses after vaccination. However, current advances in vaccine immunology show that the route in which antigens are delivered into cells is deterministic of the type of adaptive immune response evoked by vaccination. Antigens delivered by the intracellular route induce MHC-I restricted CD8+ responses while antigens presented through the extracellular route activate MHC-II restricted CD4+ responses implying that the route of antigen delivery is a conduit to induction of B- or T-cell immune responses. In finfish, different antigen delivery systems have been explored that include live, DNA, inactivated whole virus, fusion protein, virus-like particles, and subunit vaccines although mechanisms linking these delivery systems to protective immunity have not been studied in detail. Hence, in this review we provide a synopsis of different strategies used to administer viral antigens via the intra- or extracellular compartments. Further, we highlight the differences in immune responses induced by antigens processed by the endogenous route compared to exogenously processed antigens. Overall, we anticipate that the synopsis put together in this review will shed insights into limitations and successes of the current vaccination strategies used in finfish vaccinology.

  11. Differing rates of antibody acquisition to merozoite antigens in malaria: implications for immunity and surveillance.

    Science.gov (United States)

    McCallum, Fiona J; Persson, Kristina E M; Fowkes, Freya J I; Reiling, Linda; Mugyenyi, Cleopatra K; Richards, Jack S; Simpson, Julie A; Williams, Thomas N; Gilson, Paul R; Hodder, Anthony N; Sanders, Paul R; Anders, Robin F; Narum, David L; Chitnis, Chetan; Crabb, Brendan S; Marsh, Kevin; Beeson, James G

    2017-04-01

    Antibodies play a key role in acquired human immunity to Plasmodium falciparum (Pf) malaria and target merozoites to reduce or prevent blood-stage replication and the development of disease. Merozoites present a complex array of antigens to the immune system, and currently, there is only a partial understanding of the targets of protective antibodies and how responses to different antigens are acquired and boosted. We hypothesized that there would be differences in the rate of acquisition of antibodies to different antigens and how well they are boosted by infection, which impacts the acquisition of immunity. We examined responses to a range of merozoite antigens in 2 different cohorts of children and adults with different age structures and levels of malaria exposure. Overall, antibodies were associated with age, exposure, and active infection, and the repertoire of responses increased with age and active infection. However, rates of antibody acquisition varied between antigens and different regions within an antigen following exposure to malaria, supporting our hypothesis. Antigen-specific responses could be broadly classified into early response types in which antibodies were acquired early in childhood exposure and late response types that appear to require substantially more exposure for the development of substantial levels. We identified antigen-specific responses that were effectively boosted after recent infection, whereas other responses were not. These findings advance our understanding of the acquisition of human immunity to malaria and are relevant to the development of malaria vaccines targeting merozoite antigens and the selection of antigens for use in malaria surveillance. © Society for Leukocyte Biology.

  12. Concerted activity of IgG1 antibodies and IL-4/IL-25-dependent effector cells trap helminth larvae in the tissues following vaccination with defined secreted antigens, providing sterile immunity to challenge infection.

    Directory of Open Access Journals (Sweden)

    James P Hewitson

    2015-03-01

    Full Text Available Over 25% of the world's population are infected with helminth parasites, the majority of which colonise the gastrointestinal tract. However, no vaccine is yet available for human use, and mechanisms of protective immunity remain unclear. In the mouse model of Heligmosomoides polygyrus infection, vaccination with excretory-secretory (HES antigens from adult parasites elicits sterilising immunity. Notably, three purified HES antigens (VAL-1, -2 and -3 are sufficient for effective vaccination. Protection is fully dependent upon specific IgG1 antibodies, but passive transfer confers only partial immunity to infection, indicating that cellular components are also required. Moreover, immune mice show greater cellular infiltration associated with trapping of larvae in the gut wall prior to their maturation. Intra-vital imaging of infected intestinal tissue revealed a four-fold increase in extravasation by LysM+GFP+ myeloid cells in vaccinated mice, and the massing of these cells around immature larvae. Mice deficient in FcRγ chain or C3 complement component remain fully immune, suggesting that in the presence of antibodies that directly neutralise parasite molecules, the myeloid compartment may attack larvae more quickly and effectively. Immunity to challenge infection was compromised in IL-4Rα- and IL-25-deficient mice, despite levels of specific antibody comparable to immune wild-type controls, while deficiencies in basophils, eosinophils or mast cells or CCR2-dependent inflammatory monocytes did not diminish immunity. Finally, we identify a suite of previously uncharacterised heat-labile vaccine antigens with homologs in human and veterinary parasites that together promote full immunity. Taken together, these data indicate that vaccine-induced immunity to intestinal helminths involves IgG1 antibodies directed against secreted proteins acting in concert with IL-25-dependent Type 2 myeloid effector populations.

  13. Evidence for horizontal gene transfer of two antigenically distinct O antigens in Bordetella bronchiseptica

    Science.gov (United States)

    Antigenic variation is one mechanism pathogens use to avoid immune-mediated competition between closely related strains. Here, we show that two Bordetella bronchiseptica strains, RB50 and 1289, express two antigenically distinct O-antigen serotypes (O1 and O2 respectively). When 18 additional B. b...

  14. A computational framework for influenza antigenic cartography.

    Directory of Open Access Journals (Sweden)

    Zhipeng Cai

    2010-10-01

    Full Text Available 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.

  15. 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.

  16. Vectors bicistronically linking a gene of interest to the SV40 large T antigen in combination with the SV40 origin of replication enhance transient protein expression and luciferase reporter activity

    OpenAIRE

    Mahon, Matthew J.

    2011-01-01

    The Simian Virus large T antigen (SVLT) induces replication of plasmids bearing the SV40 origin of replication (SV40 ori) within mammalian cells. The internal ribosomal entry site (IRES) is an element that allows for the co-translation of proteins from one polycistronic mRNA. Through the combination of these elements, IRES-dependent co-expression of a protein of interest and the SVLT, either constitutive or regulated, on plasmids bearing the SV40 ori generates a positive feedback loop, result...

  17. Focused antibody response to influenza linked to antigenic drift.

    Science.gov (United States)

    Huang, Kuan-Ying A; Rijal, Pramila; Schimanski, Lisa; Powell, Timothy J; Lin, Tzou-Yien; McCauley, John W; Daniels, Rodney S; Townsend, Alain R

    2015-07-01

    The selective pressure that drives antigenic changes in influenza viruses is thought to originate from the human immune response. Here, we have characterized the B cell repertoire from a previously vaccinated donor whose serum had reduced neutralizing activity against the recently evolved clade 6B H1N1pdm09 viruses. While the response was markedly polyclonal, 88% of clones failed to recognize clade 6B viruses; however, the ability to neutralize A/USSR/90/1977 influenza, to which the donor would have been exposed in childhood, was retained. In vitro selection of virus variants with representative monoclonal antibodies revealed that a single amino acid replacement at residue K163 in the Sa antigenic site, which is characteristic of the clade 6B viruses, was responsible for resistance to neutralization by multiple monoclonal antibodies and the donor serum. The K163 residue lies in a part of a conserved surface that is common to the hemagglutinins of the 1977 and 2009 H1N1 viruses. Vaccination with the 2009 hemagglutinin induced an antibody response tightly focused on this common surface that is capable of selecting current antigenic drift variants in H1N1pdm09 influenza viruses. Moreover, amino acid replacement at K163 was not highlighted by standard ferret antisera. Human monoclonal antibodies may be a useful adjunct to ferret antisera for detecting antigenic drift in influenza viruses.

  18. Prognostic value of antigen expression in multiple myeloma: a PETHEMA/GEM study on 1265 patients enrolled in four consecutive clinical trials.

    Science.gov (United States)

    Arana, P; Paiva, B; Cedena, M-T; Puig, N; Cordon, L; Vidriales, M-B; Gutierrez, N C; Chiodi, F; Burgos, L; Anglada, L-L; Martinez-Lopez, J; Hernandez, M-T; Teruel, A-I; Gironella, M; Echeveste, M-A; Rosiñol, L; Martinez, R; Oriol, A; De la Rubia, J; Orfao, A; Blade, J; Lahuerta, J-J; Mateos, M-V; San Miguel, J-F

    2017-11-03

    Persistence of minimal residual disease (MRD) after treatment for myeloma predicts inferior outcomes, but within MRD-positive patients there is great heterogeneity with both early and very late relapses. Among different MRD techniques, flow cytometry provides additional information about antigen expression on tumor cells, which could potentially contribute to stratify MRD-positive patients. We investigated the prognostic value of those antigens required to monitor MRD in 1265 newly diagnosed patients enrolled in the GEM2000, GEM2005MENOS65, GEM2005MAS65 and GEM2010MAS65 protocols. Overall, CD19pos, CD27neg, CD38lo, CD45pos, CD81pos, CD117neg and CD138lo expression predicted inferior outcomes. Through principal component analysis, we found that simultaneous CD38lowCD81posCD117neg expression emerged as the most powerful combination with independent prognostic value for progression-free survival (HR:1.69; P=0.002). This unique phenotypic profile retained prognostic value among MRD-positive patients. We then used next-generation flow to determine antigen stability throughout the course of the disease, and found that the expression of antigens required to monitor MRD is mostly stable from diagnosis to MRD stages, except for CD81 whose expression progressively increased from baseline to chemoresistant tumor cells (14 vs 28%). Altogether, we showed that the phenotypic profile of tumor cells provides additional prognostic information, and could be used to further predict risk of relapse among MRD-positive patients.Leukemia advance online publication, 19 December 2017; doi:10.1038/leu.2017.320.

  19. 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.

  20. 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.

  1. Role of phagocytosis in activation of the coagulation system in Streptococcus sanguis endocarditis.

    Science.gov (United States)

    Bancsi, M J; Veltrop, M H; Bertina, R M; Thompson, J

    1996-12-01

    The formation of vegetations consisting of fibrin, cellular elements, humoral factors, and bacteria is the central event in the pathogenesis of bacterial endocarditis. Fibrin formation occurs on the vegetation, the coagulation system being activated locally via the expression of tissue factor (TF) on fibrin-adherent monocytes. This study was performed to assess the importance of phagocytosis of fibrin-adherent Streptococcus sanguis in the stimulation of TF expression on fibrin-adherent monocytes, as well as a role for "frustrated" phagocytosis. With the latter process, these cells are unable to remove bacteria from the fibrin surface but nonetheless might be activated to generate TF. We found that serum was not required for the stimulation of TF expression by fibrin-adherent monocytes in the presence of S. sanguis in an in vitro model for bacterial endocarditis. The bacterial adhesin dextran did not influence the TF activity (TFA) of fibrin-adherent monocytes: TFA was the same after stimulation with a dextran-positive streptococcus as with its dextran-negative mutant. Furthermore, dextran did not influence the TFA of endocardial vegetations, which was the same for vegetations isolated from rabbits infected either with dextran-positive S. sanguis or its dextran-negative mutant. These results do not support the hypothesis that in bacterial endocarditis (frustrated) phagocytosis significantly contributes to TF expression on vegetation-adherent monocytes. Fibronectin, however, although not influencing the fibrin binding of the streptococci, did enhance the TFA of monocytes in a concentration-dependent manner. We conclude that although streptococci do enhance expression of TFA on monocytes, phagocytosis and bacterial adhesins do not play a major role in this process. Stimulation of monocyte TFA may be more dependent on interactions between monocytes and the vegetational surface via fibronectin receptors, such as VLA 4 and VLA 5 (very late antigens 4 and 5).

  2. P System antigenic determiners expression in Ascaris lumbricoides

    Directory of Open Access Journals (Sweden)

    Ponce De León Patricia

    2003-01-01

    Full Text Available The P System antigens have been detected in numerous parasites, bacterias and viruses, nevertheless the clinical significance is still unknown. The aim was to study the presence of P1 antigenic determiners in A. lumbricoides extracts by means of the use of 6 different monoclonal antibodies of well-known concentrations and Ig class. We worked with 14 A. lumbricoides extracts. Inhibition Agglutination Test was made in a bromelin enzymatic medium and 4 masculineC temperature. Titre, Score and Sensitivity Parameter were determined for each monoclonal antibody against red cells suspension used as revealing system. Ten extracts inhibited the agglutination of all anti P1 monoclonal antibodies. The 4 remaining extracts only inhibited the agglutination of some of them. It is demonstrated that the extracts have P1 activity. This activity is independent of titre, Score, Sensitivity Parameter, concentration and Ig class and it depends on the epitope at which the monoclonal antibody is directed.

  3. T cells specific for lipid antigens.

    Science.gov (United States)

    Mori, Lucia; De Libero, Gennaro

    2012-09-01

    Lipid-specific T cells are important participants in human immune responses. Recognition of lipid antigens contributes to host defense against pathogens that can cause debilitating diseases, including mycobacterial, viral, and parasitic infections. Lipid-specific T cells also play important roles in various autoimmune diseases, atherosclerosis, and in tumor surveillance. A better understanding of the mechanisms that regulate lipid-reactive T-cell functions will enable the development of novel therapies across a wide range of diseases. In recent years, our laboratory has investigated lipid antigen specificities, mechanisms of lipid antigen presentation, molecular interaction of lipid antigens with CD1 antigen-presenting molecules, and the pathogenic and regulatory functions of lipid-specific T cells in a variety of disease settings. In this review, we present recent data that illustrate the critical role played by lipid-specific immune responses in host protection, with a particular focus on human studies.

  4. Biological Function and Molecular Mapping of M Antigen in Yeast Phase of Histoplasma capsulatum

    Science.gov (United States)

    Guimarães, Allan Jefferson; Hamilton, Andrew John; de M. Guedes, Herbert Leonel

    2008-01-01

    Histoplasmosis, due to the intracellular fungus Histoplasma capsulatum, can be diagnosed by demonstrating the presence of antibodies specific to the immunodominant M antigen. However, the role of this protein in the pathogenesis of histoplasmosis has not been elucidated. We sought to structurally and immunologically characterize the protein, determine yeast cell surface expression, and confirm catalase activity. A 3D-rendering of the M antigen by homology modeling revealed that the structures and domains closely resemble characterized fungal catalases. We generated monoclonal antibodies (mAbs) to the protein and determined that the M antigen is present on the yeast cell surface and in cell wall/cell membrane preparations. Similarly, we found that the majority of catalase activity was in extracts containing fungal surface antigens and that the M antigen is not significantly secreted by live yeast cells. The mAbs also identified unique epitopes on the M antigen. The localization of the M antigen to the cell surface of H. capsulatum yeast and the characterization of the protein's major epitopes have important implications since it demonstrates that although the protein may participate in protecting the fungus against oxidative stress it is also accessible to host immune cells and antibody. PMID:18927619

  5. Impairments of Antigen-Presenting Cells in Pulmonary Tuberculosis

    Directory of Open Access Journals (Sweden)

    Ludmila V. Sakhno

    2015-01-01

    Full Text Available The phenotype and functional properties of antigen-presenting cells (APC, that is, circulating monocytes and generated in vitro macrophages and dendritic cells, were investigated in the patients with pulmonary tuberculosis (TB differing in lymphocyte reactivity to M. tuberculosis antigens (PPD-reactive versus PPD-anergic patients. We revealed the distinct impairments in patient APC functions. For example, the monocyte dysfunctions were displayed by low CD86 and HLA-DR expression, 2-fold increase in CD14+CD16+ expression, the high numbers of IL-10-producing cells, and enhanced IL-10 and IL-6 production upon LPS-stimulation. The macrophages which were in vitro generated from peripheral blood monocytes under GM-CSF were characterized by Th1/Th2-balance shifting (downproduction of IFN-γ coupled with upproduction of IL-10 and by reducing of allostimulatory activity in mixed lymphocyte culture. The dendritic cells (generated in vitro from peripheral blood monocytes upon GM-CSF + IFN-α were characterized by impaired maturation/activation, a lower level of IFN-γ production in conjunction with an enhanced capacity to produce IL-10 and IL-6, and a profound reduction of allostimulatory activity. The APC dysfunctions were found to be most prominent in PPD-anergic patients. The possible role of APC impairments in reducing the antigen-specific T-cell response to M. tuberculosis was discussed.

  6. O-antigen protects gram-negative bacteria from histone killing.

    Directory of Open Access Journals (Sweden)

    Catherine Chaput

    Full Text Available Beyond their traditional role of wrapping DNA, histones display antibacterial activity to Gram-negative and -positive bacteria. To identify bacterial components that allow survival to a histone challenge, we selected resistant bacteria from homologous Escherichia coli libraries that harbor plasmids carrying pieces of the chromosome in different sizes. We identified genes required for exopolysaccharide production and for the synthesis of the polysaccharide domain of the lipopolysaccharide, called O-antigen. Indeed, O-antigen and exopolysaccharide conferred further resistance to histones. Notably, O-antigen also conferred resistance to histones in the pathogens Shigella flexneri and Klebsiella pneumoniae.

  7. 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.

  8. Development of pH-sensitive Dextran Derivatives with Strong Adjuvant Function and Their Application to Antigen Delivery.

    Science.gov (United States)

    Yuba, Eiji; Uesugi, Shinya; Miyazaki, Maiko; Kado, Yuna; Harada, Atsushi; Kono, Kenji

    2017-08-04

    To achieve efficient cancer immunotherapy, the induction of cytotoxic T lymphocyte-based cellular immunity is necessary. In order to induce cellular immunity, antigen carriers that can deliver antigen into cytosol of antigen presenting cells and can activate these cells are required. We previously developed 3-methyl glutarylated dextran (MGlu-Dex) for cytoplasmic delivery of antigen via membrane disruption ability at weakly acidic pH in endosome/lysosomes. MGlu-Dex-modified liposomes delivered model antigens into cytosol of dendritic cells and induced antigen-specific cellular immunity. However, their antitumor effects were not enough to complete the regression of the tumor. In this study, antigen delivery performance of dextran derivatives was improved by the introduction of more hydrophobic spacer groups next to carboxyl groups. 2-Carboxycyclohexane-1-carboxylated dextran (CHex-Dex) was newly synthesized as pH-responsive dextran derivative. CHex-Dex formed stronger hydrophobic domains at extremely weak acidic pH and destabilized lipid membrane more efficiently than MGlu-Dex. CHex-Dex-modified liposomes were taken up by dendritic cells 10 times higher than MGlu-Dex-modified liposomes and delivered model antigen into cytosol. Furthermore, CHex-Dex achieved 600 times higher IL-12 production from dendritic cells than MGlu-Dex. Therefore, CHex-Dex is promising as multifunctional polysaccharide having both cytoplasmic antigen delivery function and strong activation property of dendritic cells for induction of cellular immunity.

  9. Humoral immune responses against the Mycobacterium tuberculosis 38-kilodalton, MTB48, and CFP-10/ESAT-6 antigens in tuberculosis.

    Science.gov (United States)

    Wu, Xueqiong; Yang, Yourong; Zhang, Junxian; Li, Bangying; Liang, Yan; Zhang, Chuiying; Dong, Mei; Cheng, Hongbing; He, Jufang

    2010-03-01

    The diagnosis of smear-negative and culture-negative patients with active tuberculosis (TB) is challenging. The detection of Mycobacterium tuberculosis-specific antibodies in human sera has been an important diagnostic aid. However, detection of antibody responses to a single antigen usually has a low sensitivity for diagnosis of TB. In this study, humoral immune responses against recombinant M. tuberculosis 38-kDa, MTB48, and CFP-10/ESAT-6 (culture filtrate protein 10/6-kDa early secreted antigen target of M. tuberculosis) antigens in 250 Chinese TB patients and 260 healthy subjects were evaluated by an enzyme-linked immunosorbent assay (ELISA). The levels of antibodies against those antigens in TB patients, even in bacterium-negative ones, were significantly higher than those in healthy subjects (P CFP-10/ESAT-6 antigens, in TB patients were 73.6%, 73.2%, and 60.4%, respectively, with specificities of 85.4%, 77.7%, and 73.8%, respectively. Importantly, the sensitivity to positively detect humoral responses to one of the antigens increased further. Our data suggest that the humoral immune responses to M. tuberculosis antigens in TB patients are heterogeneous. The 38-kDa, MTB48, and CFP-10/ESAT-6 antigens can be used as the cocktail antigens in the serodiagnosis of active TB, especially for smear- or culture-negative TB cases.

  10. Antigen cross-presentation by dendritic cell subsets: one general or all sergeants?

    Science.gov (United States)

    Nierkens, Stefan; Tel, Jurjen; Janssen, Edith; Adema, Gosse J.

    2015-01-01

    Antigen cross-presentation describes the process through which dendritic cells (DCs) acquire exogenous antigens for presentation on MHC class I molecules. The ability to cross-present has been thought of as a feature of specialized DC subsets. Emerging data, however, suggest that the cross-presenting ability of each DC subset is tuned by and dependent on several factors, such as DC location and activation status, and the type of antigen and inflammatory signals. Thus, we argue that capacity of cross-presentation is not an exclusive trait of one or several distinct DC subtypes, but rather a common feature of the DC family in both mice and humans. Understanding DC subset activation and antigen-presentation pathways might yield improved tools and targets to exploit the unique cross-presenting capacity of DCs in immunotherapy. PMID:23540650

  11. Cell-to-Cell Transfer of M. tuberculosis Antigens Optimizes CD4 T Cell Priming

    Science.gov (United States)

    Srivastava, Smita; Ernst, Joel D.

    2014-01-01

    SUMMARY During Mycobacterium tuberculosis and other respiratory infections, optimal T cell activation requires pathogen transport from the lung to a local draining lymph node (LN). However, the infected inflammatory monocyte-derived dendritic cells (DCs) that transport M. tuberculosis to the local lymph node are relatively inefficient at activating CD4 T cells, possibly due to bacterial inhibition of antigen presentation. We found that infected migratory DCs release M. tuberculosis antigens as soluble, unprocessed proteins for uptake and presentation by uninfected resident lymph node DCs. This transfer of bacterial proteins from migratory to local DCs results in optimal priming of antigen-specific CD4 T cells, which are essential in controlling tuberculosis. Additionally, this mechanism does not involve transfer of the whole bacterium and is distinct from apoptosis or exosome shedding. These findings reveal a mechanism that bypasses pathogen inhibition of antigen presentation by infected cells and generates CD4 T cell responses that control the infection. PMID:24922576

  12. Comparison of different methods for localizing antigenic regions in histone H2A.

    Science.gov (United States)

    Muller, S; Plaue, S; Couppez, M; Van Regenmortel, M H

    1986-06-01

    Four different variations of enzyme-linked immunosorbent assays (ELISA) were used to analyze the antigenic structure of histone H2A. Eleven natural and 10 synthetic peptides of H2A were tested for their capacity to bind antibodies raised against the complete molecule in a direct binding assay. Results were compared to those obtained in a direct test using several peptide-BSA conjugates. The capacity of peptides to inhibit the reaction between H2A antibodies and the complete H2A molecule or large fragments of it was also measured. Inhibition assays detected antigenic activity in a large number of peptides than did direct binding assays. Antisera raised against eight synthetic, unconjugated peptides all reacted with histone H2A in ELISA. Using as probes peptides of 14-21 residues, at least 11 antigenic regions could be recognized, indicating that virtually the entire H2A polypeptide chain possessed antigenic activity.

  13. Antigenic modulation and rituximab resistance.

    Science.gov (United States)

    Taylor, Ronald P; Lindorfer, Margaret A

    2010-04-01

    Several types of B-cell lymphoma have been successfully treated with rituximab, and approval by the US Food and Drug Administration for use of rituximab in the treatment of rheumatoid arthritis has increased interest in targeting CD20 on B cells for other indications. Although large amounts of rituximab can be infused into humans with no apparent dose-limiting toxicity, recent evidence suggests that the body's effector mechanisms, including complement-mediated cytotoxicity and natural killer (NK) cell-mediated killing, can be saturated or exhausted at high burdens of rituximab-opsonized B cells. One of the consequences of this saturation phenomenon is that the opsonized B cells are instead processed by a different pathway mediated by FcgammaR on effector cells. In this alternative pathway, both rituximab and CD20 are removed ("shaved") from the B cells and are taken up by monocytes/macrophages. This process, formerly called antigenic modulation, appears to occur in several compartments in the body and may play a key role in the development of resistance to rituximab therapy.

  14. Evaluation by ELISA of Anisakis simplex Larval Antigen Purified by Affinity Chromatography

    Directory of Open Access Journals (Sweden)

    Rodero M

    2002-01-01

    Full Text Available In order to improve the specificity and sensitivity of the techniques for the human anisakidosis diagnosis, a method of affinity chromatography for the purification of species-specific antigens from Anisakis simplex third-stage larvae (L3 has been developed. New Zealand rabbits were immunized with A. simplex or Ascaris suum antigens or inoculated with Toxocara canis embryonated eggs. The IgG specific antibodies were isolated by means of protein A-Sepharose CL-4B beads columns. IgG anti-A. simplex and -A. suum were coupled to CNBr-activated Sepharose 4B. For the purification of the larval A. simplex antigens, these were loaded into the anti-A. simplex column and bound antigens eluted. For the elimination of the epitopes responsible for the cross-reactions, the A. simplex specific proteins were loaded into the anti-A. suum column. To prove the specificity of the isolated proteins, immunochemical analyses by polyacrylamide gel electrophoresis were carried out. Further, we studied the different responses by ELISA to the different antigenic preparations of A. simplex used, observing their capability of discriminating among the different antisera raised in rabbits (anti-A. simplex, anti-A. suum, anti-T. canis. The discriminatory capability with the anti-T. canis antisera was good using the larval A. simplex crude extract (CE antigen. When larval A. simplex CE antigen was loaded into a CNBr-activated Sepharose 4B coupled to IgG from rabbits immunized with A. simplex CE antigen, its capability for discriminate between A. simplex and A. suum was improved, increasing in the case of T. canis. The best results were obtained using larval A. simplex CE antigen loaded into a CNBr-activated Sepharose 4B coupled to IgG from rabbits immunized with adult A. suum CE antigen. When we compared the different serum dilution and antigenic concentration, we selected the working serum dilution of 1/400 and 1 mg/ml of antigenic concentration.

  15. 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.

  16. From Monoclonal Antibodies to Chimeric Antigen Receptors for the Treatment of Human Malignancies

    OpenAIRE

    Caruana, Ignazio; Diaconu, Iulia; Dotti, Gianpietro

    2014-01-01

    Monoclonal antibodies (mAbs) and their directly derived cell-based application known as chimeric antigen receptors (CARs) ensue from the need to develop novel therapeutic strategies that retain high anti-tumor activity, but carry reduced toxicity compared to conventional chemo- and radio-therapies. In this concise review article we will summarize the application of antibodies designed to target antigens expressed by tumor cells, and the transition from these antibodies to the generation of CARs.

  17. Targeting leukemia by CD1c-restricted T cells specific for a novel lipid antigen.

    Science.gov (United States)

    Lepore, Marco; de Lalla, Claudia; Mori, Lucia; Dellabona, Paolo; De Libero, Gennaro; Casorati, Giulia

    2015-03-01

    A subset of CD1c-restricted T lymphocytes exhibits strong reactivity against leukemia cells. These T cells recognize methyl-lysophosphatidic acid (mLPA), a novel lipid antigen produced by acute leukemia cells. Considering that CD1c-restricted T cells display efficacious anti-leukemia activities in a mouse model, this lipid antigen thus represents a novel target in the immunotherapy of hematological malignancies.

  18. Lymphoid cell blastogenesis as an in vitro indicator of cellular immunity to Legionella pneumophila antigens.

    OpenAIRE

    Friedman, F; Widen, R; Klein, T; Friedman, H

    1984-01-01

    The lymphocyte blastogenic transformation assay was adapted to study responsiveness of lymphoid cells from animals and humans to Legionella pneumophila antigens in vitro. Spleen cells from guinea pigs after active immunization with Legionella vaccine, but not from normal animals, responded by blast cell transformation when stimulated in vitro with killed Legionella whole-cell vaccine, sonic extracts thereof, or a purified somatic antigen. The response was dose dependent. Similar lymphocyte bl...

  19. 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.

  20. Hepatitis B virus antigens impair NK cell function.

    Science.gov (United States)

    Yang, Yinli; Han, Qiuju; Zhang, Cai; Xiao, Min; Zhang, Jian

    2016-09-01

    An inadequate immune response of the host is thought to be a critical factor causing chronic hepatitis B virus (CHB) infection. Natural killer (NK) cells, as one of the key players in the eradication and control of viral infections, were functionally impaired in CHB patients, which might contribute to viral persistence. Here, we reported that HBV antigens HBsAg and HBeAg directly inhibited NK cell function. HBsAg and/or HBeAg blocked NK cell activation, cytokine production and cytotoxic granule release in human NK cell-line NK-92 cells, which might be related to the downregulation of activating receptors and upregulation of inhibitory receptor. Furthermore, the underlying mechanisms likely involved the suppression of STAT1, NF-κB and p38 MAPK pathways. These findings implicated that HBV antigen-mediated inhibition of NK cells might be an efficient strategy for HBV evasion, targeting the early antiviral responses mediated by NK cells and resulting in the establishment of chronic virus infection. Therefore, this study revealed the relationship between viral antigens and human immune function, especially a potential important interaction between HBV and innate immune responses. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Suppression of the macrophage proteasome by ethanol impairs MHC class I antigen processing and presentation.

    Directory of Open Access Journals (Sweden)

    Alain J D'Souza

    Full Text Available Alcohol binge-drinking (acute ethanol consumption is immunosuppressive and alters both the innate and adaptive arms of the immune system. Antigen presentation by macrophages (and other antigen presenting cells represents an important function of the innate immune system that, in part, determines the outcome of the host immune response. Ethanol has been shown to suppress antigen presentation in antigen presenting cells though mechanisms of this impairment are not well understood. The constitutive and immunoproteasomes are important components of the cellular proteolytic machinery responsible for the initial steps critical to the generation of MHC Class I peptides for antigen presentation. In this study, we used an in-vitro cell culture model of acute alcohol exposure to study the effect of ethanol on the proteasome function in RAW 264.7 cells. Additionally, primary murine peritoneal macrophages obtained by peritoneal lavage from C57BL/6 mice were used to confirm our cell culture findings. We demonstrate that ethanol impairs proteasome function in peritoneal macrophages through suppression of chymotrypsin-like (Cht-L proteasome activity as well as composition of the immunoproteasome subunit LMP7. Using primary murine peritoneal macrophages, we have further demonstrated that, ethanol-induced impairment of the proteasome function suppresses processing of antigenic proteins and peptides by the macrophage and in turn suppresses the presentation of these antigens to cells of adaptive immunity. The results of this study provide an important mechanism to explain the immunosuppressive effects of acute ethanol exposure.

  2. Fast and efficient detection of tuberculosis antigens using liposome encapsulated secretory proteins of Mycobacterium tuberculosis.

    Science.gov (United States)

    Tiwari, Dileep; Haque, Shafiul; Tiwari, Ram P; Jawed, Arshad; Govender, Thavendran; Kruger, Hendrik G

    2017-04-01

    A rapid and efficient diagnostic test was developed for the detection of Mycobacterium tuberculosis antigens in serum samples of active tuberculosis (TB) and extrapulmonary TB patients via a liposomal agglutination-based method. A rapid card test has been developed to facilitate the recognition of high-affinity binding rabbit raised purified culture filtrate protein antibodies coupled on the surface of activated liposomal preparation. In the presence of TB antigens, the polyclonal antibodies bound to the liposomal particles demonstrate a visible agglutination reaction. The developed assay was simple, rapid, reliable, sensitive, and specific as a diagnostic test for the detection of antigens in serum samples of clinically confirmed cases of TB within 4-5 minutes' duration. The test was evaluated at different hospitals, medical colleges, and pathology centers, and involved 1483 participants. This investigation was conducted to detect the presence of these antigens during the period of active growth of the microorganism in serum samples for pulmonary TB and processed tissue biopsy for other extrapulmonary TB. Results obtained using this test were compared with acid-fast bacilli smear and culture results. Our study demonstrated that the newly developed liposome tuberculosis antigen card test detected antigens in our study population with approximately 97.48% sensitivity and 95.79% specificity. This is the first study to report the liposomal encapsulation of culture filtrate proteins from M. tuberculosis for diagnostic application. Copyright © 2015. Published by Elsevier B.V.

  3. Pathogen specific carbohydrate antigen microarrays: a chip for detection of Salmonella O-antigen specific antibodies.

    Science.gov (United States)

    Blixt, Ola; Hoffmann, Julia; Svenson, Stefan; Norberg, Thomas

    2008-01-01

    A Salmonella O-antigen microarray was developed by covalent coupling of oligosaccharide antigens specific for serogroups Salmonella enterica sv. Paratyphi (group A), Typhimurium (group B) and Enteritidis (group D). Antibodies were correctly detected in sera from patients with culture verified salmonellosis. High serogroup-specificity was seen with the disaccharide antigens. With the larger antigens, containing the backbone sequence Manalpha1-2Rhaalpha1-2Gal (MRG), common backbone-specific antibodies (O-antigen 12) were also detected. This is "proof of principle" that pathogen-specific carbohydrate antigen microarrays constitute a novel technology for rapid and specific serological diagnosis in either individual patients or larger sero-epidemiological and vaccine studies.

  4. Immune Efficacy of Salmonella ohio Somatic antigen in mice

    Directory of Open Access Journals (Sweden)

    Afaf Abdulrahman Yousif

    2012-12-01

    Full Text Available This study was designed to evaluate the effect of Salmonella ohio Somatic antigen on humoral and cellular immunity in mice. Two groups of mice (thirty in each were used, first group was immunized twice at two weeks’ intervals subcutaneously (S/C with 0.5 ml of somatic antigen (prepared by heat inactivation of S. ohio containing 1×108C.F. U (protein content 200 µg; second group was injected S/C with phosphate buffer saline(PBS. Blood samples were collected at 2, 4, and 6 weeks post booster dose. Humoral immunity was detected by ELISA test, while cellular immunity detected by E. rosette and delayed type hypersensitivity test (DTH. The immunized and control mice groups were challenged with 5LD50 of virulent Salmonella ohio six weeks post booster dose. IgG was increased significantly (P<0.05 at 2, 4, and 6 weeks in the immunized group, and the maximum increase of antibody titers was determined at fourth week (651.7 ± 21.3 in comparison with the control group which remained within the normal value in all times of the experiment. E. rosette test showed a significantly increase in the mean of the activated lymphocyte of the immunized group at fourth week of immunization while control group gave normal range of active lymphocyte. In DTH test, immunized group showed a significant increase in footpad thickness after 24 hours post inoculation with soluble antigen in comparison with control group. Immunized mice were resist the challenge dose 5LD50 {5x (1.5x107} of virulent Salmonella ohio and all mice of control group died within (3- 4 days. In conclusion, immunization of mice with somatic S. ohio antigen was induced humoral and cellular immune response against Salmonellosis.

  5. Prostate-Specific Antigen (PSA) Test

    Science.gov (United States)

    ... Genetics of Prostate Cancer Prostate Cancer Screening Research Prostate-Specific Antigen (PSA) Test On This Page What ... the PSA test for prostate cancer screening? Detecting prostate cancer early may not reduce the chance of ...

  6. Novel insights into lipid antigen presentation.

    Science.gov (United States)

    De Libero, Gennaro; Mori, Lucia

    2012-03-01

    T cells recognizing lipid antigens are present in large numbers in circulating blood. They exert multiple functions including immunoregulation, tumour surveillance and protection during infection. Here, we review the latest information on the mechanisms of lipid antigen presentation by CD1 molecules. Recent studies have provided insight into CD1 trafficking within the cell, lipid distribution and handling, CD1 maturation, lipid antigen processing and loading. The structural resolution of all human CD1 molecules has revealed unique features that correlate with function. Molecular mechanisms regulating CD1 expression and multiple evasion mechanisms evolved by viral and bacterial pathogens have been disclosed. With rapid progression, these studies have decoded lipid-specific immunity and have revealed the important immunological role of this type of antigen recognition. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. Human leukocyte antigen DR surface expression on CD14+ monocytes during adverse events after hematopoietic stem cell transplantation.

    Science.gov (United States)

    Döring, Michaela; Rohrer, Karin Melanie; Erbacher, Annika; Gieseke, Friederike; Schwarze, Carl-Philipp; Bader, Peter; Handgretinger, Rupert; Hofbeck, Michael; Kerst, Gunter

    2015-02-01

    The human leukocyte antigen DR surface expression on CD14+ monocytes reflects the degree to which these cells have been activated. Given the central role monocytes and macrophages play in the immune system, a decreased human leukocyte antigen DR expression on CD14+ monocytes results in a hallmark of altered immune status during systemic inflammatory response syndrome. We hypothesize that human leukocyte antigen DR expression might be similarly altered after hematopoietic stem cell transplantation and during post-transplant complications. Using flow cytometry, this study investigates the human leukocyte antigen DR surface expression of CD14+ monocytes in 30 pediatric and young adult patients up to 1 year after hematopoietic stem cell transplantation. Normal values were derived from a control group of healthy children, adolescents, and young adults. Human leukocyte antigen DR expression decreased significantly prior and during bacterial infection or sepsis. By contrast, human leukocyte antigen DR expression levels were elevated before and at the time of viremia. Human leukocyte antigen DR expression was also elevated during acute graft-versus-host disease. In contrast, the expression was reduced when patients had hepatic veno-occlusive disease. A significant decrease of human leukocyte antigen DR expression was associated with a relapse of the underlying disease and before death. Human leukocyte antigen DR expression on CD14+ monocytes appears to be a promising parameter that might allow identification of patients at risk after hematopoietic stem cell transplantation.

  8. 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

  9. T Cells Compete for Access to Antigen-Bearing Antigen-Presenting Cells

    Science.gov (United States)

    Kedl, Ross M.; Rees, William A.; Hildeman, David A.; Schaefer, Brian; Mitchell, Tom; Kappler, John; Marrack, Philippa

    2000-01-01

    These studies tested whether antigenic competition between T cells occurs. We generated CD8+ T cell responses in H-2b mice against the dominant ovalbumin epitope SIINFEKL (ova8) and subdominant epitope KRVVFDKL, using either vaccinia virus expressing ovalbumin (VV-ova) or peptide-pulsed dendritic cells. CD8+ T cell responses were visualized by major histocompatibility complex class I–peptide tetrameric molecules. Transfer of transgenic T cells with high affinity for ova8 (OT1 T cells) completely inhibited the response of host antigen-specific T cells to either antigen, demonstrating that T cells can directly compete with each other for response to antigen. OT1 cells also inhibited CD8+ T cell responses to an unrelated peptide, SIYRYGGL, providing it was presented on the same dendritic cells as ova8. These inhibitions were not due to a more rapid clearance of virus or antigen-presenting cells (APCs) by the OT1 cells. Rather, the inhibition was caused by competition for antigen and antigen-bearing cells, since it could be overcome by the injection of large numbers of antigen-pulsed dendritic cells. These results imply that common properties of T cell responses, such as epitope dominance and secondary response affinity maturation, are the result of competitive interactions between antigen-bearing APC and T cell subsets. PMID:11034600

  10. Defining the antigenic diversity of Plasmodium falciparum apical membrane antigen 1 and the requirements for a multi-allele vaccine against malaria.

    Directory of Open Access Journals (Sweden)

    Damien R Drew

    Full Text Available Apical Membrane Antigen 1 (AMA1 is a leading malaria vaccine candidate and a target of naturally-acquired human immunity. Plasmodium falciparum AMA1 is polymorphic and in vaccine trials it induces strain-specific protection. This antigenic diversity is a major roadblock to development of AMA1 as a malaria vaccine and understanding how to overcome it is essential. To assess how AMA1 antigenic diversity limits cross-strain growth inhibition, we assembled a panel of 18 different P. falciparum isolates which are broadly representative of global AMA1 sequence diversity. Antibodies raised against four well studied AMA1 alleles (W2Mef, 3D7, HB3 and FVO were tested for growth inhibition of the 18 different P. falciparum isolates in growth inhibition assays (GIA. All antibodies demonstrated substantial cross-inhibitory activity against different isolates and a mixture of the four different AMA1 antibodies inhibited all 18 isolates tested, suggesting significant antigenic overlap between AMA1 alleles and limited antigenic diversity of AMA1. Cross-strain inhibition by antibodies was only moderately and inconsistently correlated with the level of sequence diversity between AMA1 alleles, suggesting that sequence differences are not a strong predictor of antigenic differences or the cross-inhibitory activity of anti-allele antibodies. The importance of the highly polymorphic C1-L region for inhibitory antibodies and potential vaccine escape was assessed by generating novel transgenic P. falciparum lines for testing in GIA. While the polymorphic C1-L epitope was identified as a significant target of some growth-inhibitory antibodies, these antibodies only constituted a minor proportion of the total inhibitory antibody repertoire, suggesting that the antigenic diversity of inhibitory epitopes is limited. Our findings support the concept that a multi-allele AMA1 vaccine would give broad coverage against the diversity of AMA1 alleles and establish new tools to

  11. Vectors bicistronically linking a gene of interest to the SV40 large T antigen in combination with the SV40 origin of replication enhance transient protein expression and luciferase reporter activity.

    Science.gov (United States)

    Mahon, Matthew J

    2011-08-01

    The simian virus 40 large T antigen (SVLT) induces replication of plasmids bearing the SV40 origin of replication (SV40 ori) within mammalian cells. The internal ribosomal entry site (IRES) is an element that allows for the cotranslation of proteins from one polycistronic mRNA. Through the combination of these elements, IRES-dependent coexpression of a protein of interest and the SVLT, either constitutive or regulated, on plasmids bearing the SV40 ori generates a positive feedback loop, resulting in enhanced expression. A vector linking red fluorescent protein (RFP) to the IRES-SVLT element enhances fluorescence ~10-fold over that demonstrated from a vector lacking this element. In transfection-resistant CV-1 cells, the RFP-IRES-SVLT vector substantially increases the number of cells expressing detectable levels of RFP. Furthermore, inclusion of the IRES-SVLT/SV40 ori elements in standard luciferase-based reporter gene constructs and associated effectors results in marked increases in luminescent output and sensitivity, using the β-catenin/TCF pathway and the mammalian two-hybrid assay as models. Ultimately, vector systems combining these well-established elements (IRES-SVLT/SV40 ori) will increase the utility of transient transfection for the production of recombinant proteins, the use of transfection-resistant cell lines, and the effectiveness of luciferase-based high-throughput screening assays.

  12. Pulmonary responses to pathogen-specific antigens in latent Mycobacterium tuberculosis infection.

    Science.gov (United States)

    Jarvela, Jessica R; Tuscano, Lori; Lee, Hung; Silver, Richard F

    2016-01-01

    In this study, we used ELISPOT to quantify frequencies of bronchoalveolar lavage (BAL) and peripheral blood T cells capable of producing IFNγ in response to PPD, antigen 85B, and Mtb-specific antigens CFP-10 and ESAT-6 in individuals with latent tuberculosis infection (LTBI) and Mtb-naïve controls. Compared to peripheral blood, BAL cells of LTBI subjects displayed significant enrichment for T cells responding to PPD, antigen 85B, and CFP-10, but not to ESAT-6. Baseline BAL cells of LTBI subjects displayed significant production of Mig (CXCL9) in response to PPD, antigen 85B, and CFP-10 as well. These findings suggest that enrichment for Mtb-specific T cells within BAL is not unique to active pulmonary tuberculosis and may, to the contrary, contribute to protection from re-infection in Mtb immune individuals. Published by Elsevier Ltd.

  13. Western blot assay for quantitative and qualitative antigen detection in vaccine development.

    Science.gov (United States)

    Kumar, Sanjai; Zheng, Hong; Mahajan, Babita; Kozakai, Yukiko; Morin, Merribeth; Locke, Emily

    2014-05-01

    Immunological methods for quantitative measurement, antigenic characterization, and monitoring the stability of active immunogenic component(s) are a critical need in the vaccine development process. This unit describes an enhanced chemiluminescence-based western blot for quantitative detection of Plasmodium falciparum circumsporozoite protein (PfCSP), a major malaria candidate vaccine antigen. The most salient features of this assay are its high sensitivity and reproducibility; it can reliably detect ∼5 to 10 pg PfCSP expressed on native parasites or recombinantly expressed in Escherichia coli. Although described for a specific vaccine antigen, this assay should be applicable for any antigen-antibody combination for which relevant detection reagents are available. Detailed stepwise experimental procedures and methods for data acquisition and analysis are described. Copyright © 2014 John Wiley & Sons, Inc.

  14. The potential for induction of autoimmune disease by a randomly-mutated self-antigen

    DEFF Research Database (Denmark)

    Pedersen, Anders Elm

    2007-01-01

    The pathology of most autoimmune diseases is well described. However, the exact event that triggers the onset of the inflammatory cascade leading to disease is less certain and most autoimmune diseases are complex idiopathic diseases with no single gene known to be causative. In many cases......, a relation to an infectious disease is described, and it is thought that microbes can play a direct role in induction of autoimmunity, for instance by molecular mimicry or bystander activation of autoreactive T cells. In contrast, less attention has been given to the possibility that modified self......-antigens can be immunogenic and lead to autoimmunity against wildtype self-antigens. In theory, modified self-antigens can arise by random errors and mutations during protein synthesis and would be recognized as foreign antigens by naïve B and T lymphocytes. Here, it is postulated that the initial auto...

  15. Genetic engineering of chimeric antigen receptors using lamprey derived variable lymphocyte receptors

    Directory of Open Access Journals (Sweden)

    Robert Moot

    2016-01-01

    Full Text Available Chimeric antigen receptors (CARs are used to redirect effector cell specificity to selected cell surface antigens. Using CARs, antitumor activity can be initiated in patients with no prior tumor specific immunity. Although CARs have shown promising clinical results, the technology remains limited by the availability of specific cognate cell target antigens. To increase the repertoire of targetable tumor cell antigens we utilized the immune system of the sea lamprey to generate directed variable lymphocyte receptors (VLRs. VLRs serve as membrane bound and soluble immune effectors analogous but not homologous to immunoglobulins. They have a fundamentally different structure than immunoglobulin (Ig-based antibodies while still demonstrating high degrees of specificity and affinity. To test the functionality of VLRs as the antigen recognition domain of CARs, two VLR-CARs were created. One contained a VLR specific for a murine B cell leukemia and the other contained a VLR specific for the human T cell surface antigen, CD5. The CAR design consisted of the VLR sequence, myc-epitope tag, CD28 transmembrane domain, and intracellular CD3ζ signaling domain. We demonstrate proof of concept, including gene transfer, biosynthesis, cell surface localization, and effector cell activation for multiple VLR-CAR designs. Therefore, VLRs provide an alternative means of CAR-based cancer recognition.

  16. Multiple cellular antigen detection by ICP-MS.

    Science.gov (United States)

    Ornatsky, O; Baranov, V I; Bandura, D R; Tanner, S D; Dick, J

    2006-01-20

    There is a great need in cell biology for the simultaneous detection of many intracellular and extracellular proteins within single cells. Current optical methods based on fluorescence activated flow cytometry are difficult to multiplex. We have developed a novel application of ICP-MS-linked metal-tagged immunophenotyping which has great potential for highly multiplexed proteomic analysis. Expression of intracellular oncogenic kinase BCR/Abl, myeloid cell surface antigen CD33, human stem cell factor receptor c-Kit and integrin receptor VLA-4 were investigated using model human leukemia cell lines. Antigens to which specific antibodies are available and are distinguishably tagged can be determined simultaneously, or multiplexed. Four commercially available tags (Au, Sm, Eu, and Tb) conjugated to secondary antibodies enable a 4-plex assay assuming that the primary antibodies are not cross-reactive. Results obtained by ICP-MS were compared with data from FACS. ICP-MS as an analytical detector possesses several advantages that enhance the performance of immunoassays, which are discussed in detail. Although multiplexing using metal-conjugated reagents is in a very early stage of research and feasibility studies, it is already apparent that more than four antigens could be accurately detected simultaneously using the ICP-MS instrument.

  17. Overexpression of squamous cell carcinoma antigen variants in hepatocellular carcinoma.

    Science.gov (United States)

    Pontisso, P; Calabrese, F; Benvegnù, L; Lise, M; Belluco, C; Ruvoletto, M G; Marino, M; Valente, M; Nitti, D; Gatta, A; Fassina, G

    2004-02-23

    Pathogenetic mechanisms of hepatocellular carcinoma (HCC) are still unclear and new tools for diagnostic and therapeutic purposes are ongoing. We have assessed whether squamous cell carcinoma antigen (SCCA), a serpin overexpressed in neoplastic cells of epithelial origin, is also expressed in liver cancer. Squamous cell carcinoma antigen was evaluated by immunohistochemistry in 65 HCCs of different aetiology and in 20 normal livers. Proliferative activity was assessed using MIB-1 antibody. In 18 surgical samples, tumour and nontumour liver tissue was available for SCCA cDNA amplification and sequencing. Squamous cell carcinoma antigen was detected in 55 out of 65 (85%) tumour specimens, but in none of the 20 controls. In the majority of the cases, the positive signal was found in the cytoplasm of more than 50% of the hepatocytes. Low or undetectable SCCA (scoreSCCA score >or=2 (mean+/-s.d.: 2%+/-2.4 vs 7.5%+/-10.3, PSCCA1 variant (G(351) to A) was identified in five cases, while SCCA1 was revealed in six cases and SCCA2 in three cases. In conclusion, SCCA variants are overexpressed in HCC, independently of tumour aetiology. A novel SCCA1 variant has been identified in one third of liver tumours.

  18. 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

  19. Skin test reactivity to dog-derived antigens.

    Science.gov (United States)

    Lutsky, I; Fink, J N; Arkins, J A; Hoffman, R; Morouse, M

    1980-05-01

    Skin test reactivity to canine antigens was studied by testing atopic patients and veterinarians using a commercially prepared mixed-dog epithelial antigen and breed-specific antigens including dander extracts, serum and urine, obtained from thirty-one different pure-bred dogs. Increased skin test reactivity was noted using breed-specific antigens as compared to the mixed-dog commercial screening extract. Variation in skin test responsivity related to specific breed antigens was also noted. The results suggest that skin tests using canine urine and serum antigens, in addition to the conventional dander antigens, may be useful in the diagnosis of hypersensitivity to dogs.

  20. Biotechnology approaches to produce potent, self-adjuvanting antigen-adjuvant fusion protein subunit vaccines.

    Science.gov (United States)

    Moyle, Peter Michael

    Traditional vaccination approaches (e.g. live attenuated or killed microorganisms) are among the most effective means to prevent the spread of infectious diseases. These approaches, nevertheless, have failed to yield successful vaccines against many important pathogens. To overcome this problem, methods have been developed to identify microbial components, against which protective immune responses can be elicited. Subunit antigens identified by these approaches enable the production of defined vaccines, with improved safety profiles. However, they are generally poorly immunogenic, necessitating their administration with potent immunostimulatory adjuvants. Since few safe and effective adjuvants are currently used in vaccines approved for human use, with those available displaying poor potency, or an inability to stimulate the types of immune responses required for vaccines against specific diseases (e.g. cytotoxic lymphocytes (CTLs) to treat cancers), the development of new vaccines will be aided by the availability of characterized platforms of new adjuvants, improving our capacity to rationally select adjuvants for different applications. One such approach, involves the addition of microbial components (pathogen-associated molecular patterns; PAMPs), that can stimulate strong immune responses, into subunit vaccine formulations. The conjugation of PAMPs to subunit antigens provides a means to greatly increase vaccine potency, by targeting immunostimulation and antigen to the same antigen presenting cell. Thus, methods that enable the efficient, and inexpensive production of antigen-adjuvant fusions represent an exciting mean to improve immunity towards subunit antigens. Herein we review four protein-based adjuvants (flagellin, bacterial lipoproteins, the extra domain A of fibronectin (EDA), and heat shock proteins (Hsps)), which can be genetically fused to antigens to enable recombinant production of antigen-adjuvant fusion proteins, with a focus on their

  1. Cancer vaccines: an update with special focus on ganglioside antigens.

    Science.gov (United States)

    Bitton, Roberto J; Guthmann, Marcel D; Gabri, Mariano R; Carnero, Ariel J L; Alonso, Daniel F; Fainboim, Leonardo; Gomez, Daniel E

    2002-01-01

    Vaccine development is one of the most promising and exciting fields in cancer research; numerous approaches are being studied to developed effective cancer vaccines. The aim of this form of therapy is to teach the patient's immune system to recognize the antigens expressed in tumor cells, but not in normal tissue, to be able to destroy these abnormal cells leaving the normal cells intact. In other words, is an attempt to teach the immune system to recognize antigens that escaped the immunologic surveillance and are by it, therefore able to survive and, in time, disseminate. However each research group developing a cancer vaccine, uses a different technology, targeting different antigens, combining different carriers and adjuvants, and using different immunization schedules. Most of the vaccines are still experimental and not approved by the US or European Regulatory Agencies. In this work, we will offer an update in the knowledge in cancer immunology and all the anticancer vaccine approaches, with special emphasis in ganglioside based vaccines. It has been demonstrated that quantitative and qualitative changes occur in ganglioside expression during the oncogenic transformation. Malignant transformation appears to activate enzymes associated with ganglioside glycosylation, resulting in altered patterns of ganglioside expression in tumors. Direct evidence of the importance of gangliosides as potential targets for active immunotherapy has been suggested by the observation that human monoclonal antibodies against these glycolipids induce shrinkage of human cutaneous melanoma metastasis. Thus, the cellular over-expression and shedding of gangliosides into the interstitial space may play a central role in cell growth regulation, immune tolerance and tumor-angiogenesis, therefore representing a new target for anticancer therapy. Since 1993 researchers at the University of Buenos Aires and the University of Quilmes (Argentina), have taken part in a project carried out by

  2. Antigen cross-presentation of immune complexes

    Directory of Open Access Journals (Sweden)

    Barbara ePlatzer

    2014-04-01

    Full Text Available The ability of dendritic cells (DC to cross-present tumor antigens has long been a focus of interest of physicians, as well as basic scientists, that aim to establish efficient cell-based cancer immune therapy. A prerequisite for exploiting this pathway for therapeutic purposes is a better understanding of the mechanisms that underlie the induction of tumor-specific cytotoxic T-lymphocyte (CTL responses when initiated by DCs via cross-presentation. The ability of humans DC to perform cross-presentation is of utmost interest as this cell type is a main target for cell-based immunotherapy in humans. The outcome of a cross-presentation event is guided by the nature of the antigen, the form of antigen uptake and the subpopulation of DCs that performs presentation. Generally, CD8+ DCs are considered to be the most potent cross-presenting DCs. This paradigm, however, only applies to soluble antigens. During adaptive immune responses, immune complexes form when antibodies interact with their specific epitopes on soluble antigens. Immunoglobulin G (IgG immune complexes target Fc-gamma receptors on DCs to shuttle exogenous antigens efficiently into the cross-presentation pathway. This receptor mediated cross-presentation pathway is a well-described route for the induction of strong CD8+ T cell responses. IgG-mediated cross-presentation is intriguing because it permits the CD8- DCs, which are commonly considered to be weak cross-presenters, to efficiently cross-present. Engaging multiple DC subtypes for cross-presentation might be a superior strategy to boost CTL responses in vivo. We here summarize our current understanding of how DCs use IgG-complexed antigens for the efficient induction of CTL responses. Because of its importance for human cell therapy, we also review the recent advances in the characterization of cross-presentation properties of human DC subsets.

  3. Antigen cross-presentation of immune complexes.

    Science.gov (United States)

    Platzer, Barbara; Stout, Madeleine; Fiebiger, Edda

    2014-01-01

    The ability of dendritic cells (DCs) to cross-present tumor antigens has long been a focus of interest to physicians, as well as basic scientists, that aim to establish efficient cell-based cancer immune therapy. A prerequisite for exploiting this pathway for therapeutic purposes is a better understanding of the mechanisms that underlie the induction of tumor-specific cytotoxic T-lymphocyte (CTL) responses when initiated by DCs via cross-presentation. The ability of humans DC to perform cross-presentation is of utmost interest, as this cell type is a main target for cell-based immunotherapy in humans. The outcome of a cross-presentation event is guided by the nature of the antigen, the form of antigen uptake, and the subpopulation of DCs that performs presentation. Generally, CD8α(+) DCs are considered to be the most potent cross-presenting DCs. This paradigm, however, only applies to soluble antigens. During adaptive immune responses, immune complexes form when antibodies interact with their specific epitopes on soluble antigens. Immunoglobulin G (IgG) immune complexes target Fc-gamma receptors on DCs to shuttle exogenous antigens efficiently into the cross-presentation pathway. This receptor-mediated cross-presentation pathway is a well-described route for the induction of strong CD8(+) T cell responses. IgG-mediated cross-presentation is intriguing because it permits the CD8(-) DCs, which are commonly considered to be weak cross-presenters, to efficiently cross-present. Engaging multiple DC subtypes for cross-presentation might be a superior strategy to boost CTL responses in vivo. We here summarize our current understanding of how DCs use IgG-complexed antigens for the efficient induction of CTL responses. Because of its importance for human cell therapy, we also review the recent advances in the characterization of cross-presentation properties of human DC subsets.

  4. Bystander T cells in human immune responses to dengue antigens

    Directory of Open Access Journals (Sweden)

    Suwannasaen Duangchan

    2010-09-01

    Full Text Available Abstract Background Previous studies of T cell activation in dengue infection have focused on restriction of specific T cell receptors (TCRs and classical MHC molecules. However, bystander T cell activation, which is TCR independent, occurs via cytokines in other viral infections, both in vitro and in vivo, and enables T cells to bypass certain control checkpoints. Moreover, clinical and pathological evidence has pointed to cytokines as the mediators of dengue disease severity. Therefore, we investigated bystander T cell induction by dengue viral antigen. Results Whole blood samples from 55 Thai schoolchildren aged 13-14 years were assayed for in vitro interferon-gamma (IFN-γ induction in response to inactivated dengue serotype 2 antigen (Den2. The contribution of TCR-dependent and independent pathways was tested by treatment with cyclosporin A (CsA, which inhibits TCR-dependent activation of T cells. ELISA results revealed that approximately 72% of IFN-γ production occurred via the TCR-dependent pathway. The major IFN-γ sources were natural killer (NK (mean ± SE = 55.2 ± 3.3, CD4+T (24.5 ± 3.3 and CD8+T cells (17.9 ± 1.5, respectively, as demonstrated by four-color flow cytometry. Interestingly, in addition to these cells, we found CsA-resistant IFN-γ producing T cells (CD4+T = 26.9 ± 3.6% and CD8+T = 20.3 ± 2.1% implying the existence of activated bystander T cells in response to dengue antigen in vitro. These bystander CD4+ and CD8+T cells had similar kinetics to NK cells, appeared after 12 h and were inhibited by anti-IL-12 neutralization indicating cytokine involvement. Conclusions This study described immune cell profiles and highlighted bystander T cell activation in response to dengue viral antigens of healthy people in an endemic area. Further studies on bystander T cell activation in dengue viral infection may reveal the immune mechanisms that protect or enhance pathogenesis of secondary dengue infection.

  5. Long-Lasting Activation of the Transcription Factor CREB in Sensory Neurons by Interleukin-1β During Antigen-Induced Arthritis in Rats: A Mechanism of Persistent Arthritis Pain?

    Science.gov (United States)

    Segond von Banchet, Gisela; König, Christian; Patzer, Jessica; Eitner, Annett; Leuchtweis, Johannes; Ebbinghaus, Matthias; Boettger, Michael K; Schaible, Hans-Georg

    2016-02-01

    In spite of successful treatment of immune-mediated arthritis, many patients still experience pain. We undertook this study to investigate whether antigen-induced arthritis (AIA) in rats triggers neuronal changes in sensory neurons that outlast the inflammatory process. We induced unilateral AIA in the knee joint and assessed in sensory neurons the expression of CREB, a transcription factor that regulates genes involved in neuronal plasticity. We tested whether neutralization of the effects of tumor necrosis factor (TNF) by etanercept or infliximab or neutralization of the effects of interleukin-1β (IL-1β) by anakinra influences the up-regulation of phospho-CREB, and we studied the up-regulation of phospho-CREB by IL-1β and TNF in cultured dorsal root ganglion (DRG) neurons. Unilateral AIA caused bilateral up-regulation of phospho-CREB in lumbar DRG neurons. While inflammation and pain subsided within 21 days, the up-regulation of phospho-CREB still persisted on day 42. At this time point mechanical hyperalgesia at the knee reappeared in the absence of swelling. TNF neutralization during AIA significantly reduced pain-related behavior but did not prevent phospho-CREB up-regulation. In contrast, anakinra, which only reduced thermal hyperalgesia, prevented phospho-CREB up-regulation, suggesting a role of IL-1β in this process. In cultured DRG neurons the application of IL-1β significantly enhanced phospho-CREB. Immune-mediated arthritis causes neuroplastic changes in sensory neurons that outlast the inflammatory phase. Such changes may facilitate the persistence or recurrence of pain after remission of arthritis. IL-1β is an important trigger in this process, although its neutralization barely reduced mechanical hyperalgesia during inflammation. © 2016, American College of Rheumatology.

  6. Tandem CAR T cells targeting HER2 and IL13Rα2 mitigate tumor antigen escape.

    Science.gov (United States)

    Hegde, Meenakshi; Mukherjee, Malini; Grada, Zakaria; Pignata, Antonella; Landi, Daniel; Navai, Shoba A; Wakefield, Amanda; Fousek, Kristen; Bielamowicz, Kevin; Chow, Kevin K H; Brawley, Vita S; Byrd, Tiara T; Krebs, Simone; Gottschalk, Stephen; Wels, Winfried S; Baker, Matthew L; Dotti, Gianpietro; Mamonkin, Maksim; Brenner, Malcolm K; Orange, Jordan S; Ahmed, Nabil

    2016-08-01

    In preclinical models of glioblastoma, antigen escape variants can lead to tumor recurrence after treatment with CAR T cells that are redirected to single tumor antigens. Given the heterogeneous expression of antigens on glioblastomas, we hypothesized that a bispecific CAR molecule would mitigate antigen escape and improve the antitumor activity of T cells. Here, we created a CAR that joins a HER2-binding scFv and an IL13Rα2-binding IL-13 mutein to make a tandem CAR exodomain (TanCAR) and a CD28.ζ endodomain. We determined that patient TanCAR T cells showed distinct binding to HER2 or IL13Rα2 and had the capability to lyse autologous glioblastoma. TanCAR T cells exhibited activation dynamics that were comparable to those of single CAR T cells upon encounter of HER2 or IL13Rα2. We observed that TanCARs engaged HER2 and IL13Rα2 simultaneously by inducing HER2-IL13Rα2 heterodimers, which promoted superadditive T cell activation when both antigens were encountered concurrently. TanCAR T cell activity was more sustained but not more exhaustible than that of T cells that coexpressed a HER2 CAR and an IL13Rα2 CAR, T cells with a unispecific CAR, or a pooled product. In a murine glioblastoma model, TanCAR T cells mitigated antigen escape, displayed enhanced antitumor efficacy, and improved animal survival. Thus, TanCAR T cells show therapeutic potential to improve glioblastoma control by coengaging HER2 and IL13Rα2 in an augmented, bivalent immune synapse that enhances T cell functionality and reduces antigen escape.

  7. Amount of H Antigen Expressed on Circulating von Willebrand Factor Is Modified by ABO Blood Group Genotype and Is a Major Determinant of Plasma von Willebrand Factor Antigen Levels

    National Research Council Canada - National Science Library

    O’Donnell, James; Boulton, Frank E; Manning, Richard A; Laffan, Michael A

    2002-01-01

    .... AvWF was correlated strongly with plasma levels of A transferase activity. Thus, we have clearly demonstrated a direct relationship between ABO genotype, A transferase expression, and the amount of A antigen expressed on circulating vWF...

  8. Interleukin 10 (IL-10)-mediated Immunosuppression: MARCH-I INDUCTION REGULATES ANTIGEN PRESENTATION BY MACROPHAGES BUT NOT DENDRITIC CELLS.

    Science.gov (United States)

    Mittal, Sharad K; Cho, Kyung-Jin; Ishido, Satoshi; Roche, Paul A

    2015-11-06

    Efficient immune responses require regulated antigen presentation to CD4 T cells. IL-10 inhibits the ability of dendritic cells (DCs) and macrophages to stimulate antigen-specific CD4 T cells; however, the mechanisms by which IL-10 suppresses antigen presentation remain poorly understood. We now report that IL-10 stimulates expression of the E3 ubiquitin ligase March-I in activated macrophages, thereby down-regulating MHC-II, CD86, and antigen presentation to CD4 T cells. By contrast, IL-10 does not stimulate March-I expression in DCs, does not suppress MHC-II or CD86 expression on either resting or activated DCs, and does not affect antigen presentation by activated DCs. IL-10 does, however, inhibit the process of DC activation itself, thereby reducing the efficiency of antigen presentation in a March-I-independent manner. Thus, IL-10 suppression of antigen presenting cell function in macrophages is March-I-dependent, whereas in DCs, suppression is March- I-independent. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  9. Dendritic cells derived from bone marrow cells fail to acquire and present major histocompatibility complex antigens from other dendritic cells

    Science.gov (United States)

    Bedford, Penelope A; Burke, Fiona; Stagg, Andrew J; Knight, Stella C

    2008-01-01

    Dendritic cells stimulate primary T-cell responses and a major activation route is via presentation of antigens pre-processed by other dendritic cells. This presentation of pre-processed antigens most likely proceeds through transfer of functional major histocompatibility complex (MHC) antigens through exosomes, ‘live nibbling’ or apoptotic vesicles. We hypothesized that not all dendritic cell populations may both donate MHC antigen to dendritic cells and present antigens acquired from other dendritic cells. All populations tested, including those derived from bone marrow precursor cells stimulated primary, allogeneic T-cell responses and acted as accessory cells for mitogen stimulation. Populations of responder type, splenic dendritic cells promoted allogeneic responses indirectly but those derived from bone marrow cells blocked rather than promoted T-cell proliferation. To identify mechanisms underlying this difference we studied transfer of I-A antigens between cells. Active, two-way transfer of allogeneic I-A occurred between splenic primary antigen presenting cells including CD8α+ lymphoid dendritic cells, CD8α− myeloid dendritic cells and B220+ cells; all these cell types donated as well as acquired MHC molecules. By contrast, the bone marrow-derived dendritic cells donated I-A antigens but acquired negligible amounts. Thus, dendritic cells derived directly from bone marrow cells may stimulate primary T-cell responses through transferring functional MHC to other dendritic cells but may not be able to acquire and present antigens from other dendritic cells. The evidence suggests that T-cell activation may be blocked by the presence of dendritic cells that have not matured through lymphoid tissues which are unable to acquire and present antigens pre-processed by other dendritic cells. PMID:18266716

  10. Selective culling of high avidity antigen-specific CD4+ T cells after virulent Salmonella infection

    Science.gov (United States)

    Ertelt, James M; Johanns, Tanner M; Mysz, Margaret A; Nanton, Minelva R; Rowe, Jared H; Aguilera, Marijo N; Way, Sing Sing

    2011-01-01

    Typhoid fever is a persistent infection caused by host-adapted Salmonella strains adept at circumventing immune-mediated host defences. Given the importance of T cells in protection, the culling of activated CD4+ T cells after primary infection has been proposed as a potential immune evasion strategy used by this pathogen. We demonstrate that the purging of activated antigen-specific CD4+ T cells after virulent Salmonella infection requires SPI-2 encoded virulence determinants, and is not restricted only to cells with specificity to Salmonella-expressed antigens, but extends to CD4+ T cells primed to expand by co-infection with recombinant Listeria monocytogenes. Unexpectedly, however, the loss of activated CD4+ T cells during Salmonella infection demonstrated using a monoclonal population of adoptively transferred CD4+ T cells was not reproduced among the endogenous repertoire of antigen-specific CD4+ T cells identified with MHC class II tetramer. Analysis of T-cell receptor variable segment usage revealed the selective loss and reciprocal enrichment of defined CD4+ T-cell subsets after Salmonella co-infection that is associated with the purging of antigen-specific cells with the highest intensity of tetramer staining. Hence, virulent Salmonella triggers the selective culling of high avidity activated CD4+ T-cell subsets, which re-shapes the repertoire of antigen-specific T cells that persist later after infection. PMID:22044420

  11. Plant-derived antigens as mucosal vaccines.

    Science.gov (United States)

    Mason, H S; Herbst-Kralovetz, M M

    2012-01-01

    During the last two decades, researchers have developed robust systems for recombinant subunit vaccine production in plants. Stably and transiently transformed plants have particular advantages that enable immunization of humans and animals via mucosal delivery. The initial goal to immunize orally by ingestion of plant-derived antigens has proven difficult to attain, although many studies have demonstrated antibody production in both humans and animals, and in a few cases, protection against pathogen challenge. Substantial hurdles for this strategy are low-antigen content in crudely processed plant material and limited antigen stability in the gut. An alternative is intranasal delivery of purified plant-derived antigens expressed with robust viral vectors, especially virus-like particles. The use of pattern recognition receptor agonists as adjuvants for mucosal delivery of plant-derived antigens can substantially enhance serum and mucosal antibody responses. In this chapter, we briefly review the methods for recombinant protein expression in plants, and describe progress with human and animal vaccines that use mucosal delivery routes. We do not attempt to compile a comprehensive list, but focus on studies that progressed to clinical trials or those that showed strong indications of efficacy in animals. Finally, we discuss some regulatory concerns regarding plant-based vaccines.

  12. Human Tumor Antigens Yesterday, Today, and Tomorrow.

    Science.gov (United States)

    Finn, Olivera J

    2017-05-01

    The question of whether human tumors express antigens that can be recognized by the immune system has been answered with a resounding YES. Most were identified through spontaneous antitumor humoral and cellular immune responses found in cancer patients and include peptides, glycopeptides, phosphopeptides, viral peptides, and peptides resulting from common mutations in oncogenes and tumor-suppressor genes, or common gene fusion events. Many have been extensively tested as candidates for anticancer vaccines. More recently, attention has been focused on the potentially large number of unique tumor antigens, mutated neoantigens, that are the predicted products of the numerous mutations revealed by exome sequencing of primary tumors. Only a few have been confirmed as targets of spontaneous immunity and immunosurveillance, and even fewer have been tested in preclinical and clinical settings. The field has been divided for a long time on the relative importance of shared versus mutated antigens in tumor surveillance and as candidates for vaccines. This question will eventually need to be answered in a head to head comparison in well-designed clinical trials. One advantage that shared antigens have over mutated antigens is their potential to be used in vaccines for primary cancer prevention. Cancer Immunol Res; 5(5); 347-54. ©2017 AACR. ©2017 American Association for Cancer Research.

  13. Single hemagglutinin mutations that alter both antigenicity and receptor binding avidity influence influenza virus antigenic clustering.

    Science.gov (United States)

    Li, Yang; Bostick, David L; Sullivan, Colleen B; Myers, Jaclyn L; Griesemer, Sara B; Stgeorge, Kirsten; Plotkin, Joshua B; Hensley, Scott E

    2013-09-01

    The hemagglutination inhibition (HAI) assay is the primary measurement used for identifying antigenically novel influenza virus strains. HAI assays measure the amount of reference sera required to prevent virus binding to red blood cells. Receptor binding avidities of viral strains are not usually taken into account when interpreting these assays. Here, we created antigenic maps of human H3N2 viruses that computationally account for variation in viral receptor binding avidities. These new antigenic maps differ qualitatively from conventional antigenic maps based on HAI measurements alone. We experimentally focused on an antigenic cluster associated with a single N145K hemagglutinin (HA) substitution that occurred between 1992 and 1995. Reverse-genetics experiments demonstrated that the N145K HA mutation increases viral receptor binding avidity. Enzyme-linked immunosorbent assays (ELISA) revealed that the N145K HA mutation does not prevent antibody binding; rather, viruses possessing this mutation escape antisera in HAI assays simply by attaching to cells more efficiently. Unexpectedly, we found an asymmetric antigenic effect of the N145K HA mutation. Once H3N2 viruses acquired K145, an epitope involving amino acid 145 became antigenically dominant. Antisera raised against an H3N2 strain possessing K145 had reduced reactivity to H3N2 strains possessing N145. Thus, individual mutations in HA can influence antigenic groupings of strains by altering receptor binding avidity and by changing the dominance of antibody responses. Our results indicate that it will be important to account for variation in viral receptor binding avidity when performing antigenic analyses in order to identify genuine antigenic differences among influenza virus variants.

  14. Interferon alpha inhibits antigen-specific production of proinflammatory cytokines and enhances antigen-specific transforming growth factor beta production in antigen-induced arthritis.

    Science.gov (United States)

    Chalise, Jaya; Narendra, Sudeep; Paudyal, Bhesh; Magnusson, Mattias

    2013-10-03

    Interferon alpha (IFN-α) has a complex role in autoimmunity, in that it may both enhance and prevent inflammation. We have previously shown that the presence of IFN-α at sensitization protects against subsequent antigen-triggered arthritis. To understand this tolerogenic mechanism, we performed a descriptive, hypothesis-generating study of cellular and humoral responses associated with IFN-α-mediated protection against arthritis. Arthritis was evaluated at day 28 in mice given a subcutaneous injection of methylated bovine serum albumin (mBSA), together with Freund adjuvant and 0 to 5,000 U IFN-α at days 1 and 7, followed by intraarticular injection of mBSA alone at day 21. The effect of IFN-α on mBSA-specific IgG1, IgG2a, IgG2b, IgA, and IgE was evaluated by enzyme-linked immunosorbent assay (ELISA). Cytokines in circulation and in ex vivo cultures on mBSA restimulation was evaluated with ELISA and Luminex, and the identity of cytokine-producing cells by fluorescence-activated cell sorting (FACS) analysis. Administration of IFN-α protected mice from arthritis in a dose-dependent manner but had no effect on antigen-specific antibody levels. However, IFN-α did inhibit the initial increase of IL-6, IL-10, IL-12, and TNF, and the recall response induced by intraarticular mBSA challenge of IL-1β, IL-10, IL-12, TNF, IFN-γ, and IL-17 in serum. IFN-α decreased both macrophage and CD4+ T cell-derived IFN-γ production, whereas IL-17 was decreased only in CD4+ T cells. Ex vivo, in mBSA-restimulated spleen and lymph node cell cultures, the inhibitory effect of in vivo administration of IFN-α on proinflammatory cytokine production was clearly apparent, but had a time limit. An earlier macrophage-derived, and stronger activation of the antiinflammatory cytokine transforming growth factor beta (TGF-β) was observed in IFN-α-treated animals, combined with an increase in CD4+ T cells producing TGF-β when arthritis was triggered by mBSA (day 21). Presence of IFN-α at

  15. Cytotoxic T-lymphocyte Antigen-4 Binding to SHP2 Interacting ...

    African Journals Online (AJOL)

    This phenomenon may lead to the development of new treatment strategies for autoimmune diseases and graft rejection. Keywords: Cytotoxic T-lymphocyte antigen-4, Interleukin-2, Nuclear factor of activated T-cells/Activator protein-1, SHP2 interacting transmembrane adapter protein, Autoimmune diseases, Graft rejection.

  16. Cytotoxic T-lymphocyte Antigen-4 Binding to SHP2 Interacting ...

    African Journals Online (AJOL)

    This phenomenon may lead to the development of new treatment strategies for autoimmune diseases and graft rejection. Keywords: Cytotoxic T-lymphocyte antigen-4, Interleukin-2, Nuclear factor of activated T-cells/Activator protein-1, SHP2 interacting transmembrane adapter protein, Autoimmune diseases, Graft rejection ...

  17. O-antigen delays lipopolysaccharide recognition and impairs antibacterial host defense in murine intestinal epithelial cells.

    Directory of Open Access Journals (Sweden)

    Claudia U Duerr

    2009-09-01

    Full Text Available Although Toll-like receptor (TLR 4 signals from the cell surface of myeloid cells, it is restricted to an intracellular compartment and requires ligand internalization in intestinal epithelial cells (IECs. Yet, the functional consequence of cell-type specific receptor localization and uptake-dependent lipopolysaccharide (LPS recognition is unknown. Here, we demonstrate a strikingly delayed activation of IECs but not macrophages by wildtype Salmonella enterica subsp. enterica sv. (S. Typhimurium as compared to isogenic O-antigen deficient mutants. Delayed epithelial activation is associated with impaired LPS internalization and retarded TLR4-mediated immune recognition. The O-antigen-mediated evasion from early epithelial innate immune activation significantly enhances intraepithelial bacterial survival in vitro and in vivo following oral challenge. These data identify O-antigen expression as an innate immune evasion mechanism during apical intestinal epithelial invasion and illustrate the importance of early innate immune recognition for efficient host defense against invading Salmonella.

  18. 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

  19. Antigen sampling in the fish intestine.

    Science.gov (United States)

    Løkka, Guro; Koppang, Erling Olaf

    2016-11-01

    Antigen uptake in the gastrointestinal tract may induce tolerance, lead to an immune response and also to infection. In mammals, most pathogens gain access to the host though the gastrointestinal tract, and in fish as well, this route seems to be of significant importance. The epithelial surface faces a considerable challenge, functioning both as a barrier towards the external milieu but simultaneously being the site of absorption of nutrients and fluids. The mechanisms allowing antigen uptake over the epithelial barrier play a central role for maintaining the intestinal homeostasis and regulate appropriate immune responses. Such uptake has been widely studied in mammals, but also in fish, a number of experiments have been reported, seeking to reveal cells and mechanisms involved in antigen sampling. In this paper, we review these studies in addition to addressing our current knowledge of the intestinal barrier in fish and its anatomical construction. Copyright © 2016. Published by Elsevier Ltd.

  20. Preserved MHC class II antigen processing in monocytes from HIV-infected individuals.

    Directory of Open Access Journals (Sweden)

    Laila Woc-Colburn

    2010-03-01

    Full Text Available MHC-II restricted CD4+ T cells are dependent on antigen presenting cells (APC for their activation. APC dysfunction in HIV-infected individuals could accelerate or exacerbate CD4+ T cell dysfunction and may contribute to increased levels of immunodeficiency seen in some patients regardless of their CD4+ T cell numbers. Here we test the hypothesis that APC from HIV-infected individuals have diminished antigen processing and presentation capacity.Monocytes (MN were purified by immuno-magnetic bead isolation techniques from HLA-DR1.01+ or DR15.01+ HIV-infected and uninfected individuals. MN were analyzed for surface MHC-II expression and for antigen processing and presentation capacity after overnight incubation with soluble antigen or peptide and HLA-DR matched T cell hybridomas. Surface expression of HLA-DR was 20% reduced (p<0.03 on MN from HIV-infected individuals. In spite of this, there was no significant difference in antigen processing and presentation by MN from 14 HIV-infected donors (8 HLA-DR1.01+ and 6 HLA-DR15.01+ compared to 24 HIV-uninfected HLA-matched subjects.We demonstrated that MHC class II antigen processing and presentation is preserved in MN from HIV-infected individuals. This further supports the concept that this aspect of APC function does not further contribute to CD4+ T cell dysfunction in HIV disease.

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

    Directory of Open Access Journals (Sweden)

    Cunha-Neto E.

    1999-01-01

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

  2. Binding to chromosomes of herpes simplex-related antigens in biochemically transformed cells.

    Science.gov (United States)

    Kit, S; Kurchak, M; Wray, W; Dubbs, D R

    1978-07-01

    Association of herpes simplex virus (HSV)-related antigens with chromosomes was demonstrated in human and mouse cells biochemically transformed by HSV that had been irradiated with ultraviolet light. This was accomplished by using peroxidase-anti-peroxidase immunological staining with rabbit antisera that had high neutralizing titers against both HSV-specific thymidine kinase activity and virus infectivity. Antisera-against HSV did not react with chromosomes of uninfected cells nor did normal sera react with any of the constitutents of biochemically transformed cells. Methanol/acetic acid treatment of biochemically transformed cells eliminated their nuclear staining for HSV-related antigens. In vitro binding of HSV-related antigens to chromosomes was demonstrated by incubating soluble antigens from high salt extracts of HSV-infected cells with methanol/acetic acid-fixed chromosomes of biochemically transformed or uninfected cells, followed by exposure to antiserum against HSV and peroxidase-anti-peroxidase staining. There was no staining when soluble extracts from uninfected cells were substituted for those from HSV-infected cells. The results show that cells biochemically transformed and lytically infected by HSV, respectively, contain antigens, which like the Epstein-Barr virus-associated nuclear antigen (EBNA), bind to chromosomes in vivo and in vitro.

  3. Regeneration of tumor antigen-specific CTLs utilizing iPS technology.

    Science.gov (United States)

    Maeda, Takuya; Masuda, Kyoko; Kawamoto, Hiroshi

    2016-08-01

    Tumor immunotherapy, especially tumor antigen specific T cell therapy, is currently attracting attention. However, a critical issue still awaits resolution; it is difficult to efficiently expand tumor antigen-specific T cells. To solve this problem, we are now utilizing iPS cell technology. When iPS cells are established from tumor antigen specific T cells, T cells regenerated from these iPS cells are expected to express the same TCRs as the original T cells. In line with this concept, we succeeded in regenerating tumor antigen specific cytotoxic T cells. The regenerated T cells exhibited TCR specific killing activity comparable to that of the original cells, and were able to kill leukemia cells in an antigen-specific manner. We are currently endeavoring to apply this method clinically. In the future, we intend to establish an allogeneic transfusion system, in which various tumor antigen specific T-iPS cells from a wide range of HLA haplotype homozygous donors will be lined up as a "T-iPS cell bank", with the aim of making off-the-shelf tumor immunotherapy a reality.

  4. A Mutant Library Approach to Identify Improved Meningococcal Factor H Binding Protein Vaccine Antigens.

    Directory of Open Access Journals (Sweden)

    Monica Konar

    Full Text Available Factor H binding protein (FHbp is a virulence factor used by meningococci to evade the host complement system. FHbp elicits bactericidal antibodies in humans and is part of two recently licensed vaccines. Using human complement Factor H (FH transgenic mice, we previously showed that binding of FH decreased the protective antibody responses to FHbp vaccination. Therefore, in the present study we devised a library-based method to identify mutant FHbp antigens with very low binding of FH. Using an FHbp sequence variant in one of the two licensed vaccines, we displayed an error-prone PCR mutant FHbp library on the surface of Escherichia coli. We used fluorescence-activated cell sorting to isolate FHbp mutants with very low binding of human FH and preserved binding of control anti-FHbp monoclonal antibodies. We sequenced the gene encoding FHbp from selected clones and introduced the mutations into a soluble FHbp construct. Using this approach, we identified several new mutant FHbp vaccine antigens that had very low binding of FH as measured by ELISA and surface plasmon resonance. The new mutant FHbp antigens elicited protective antibody responses in human FH transgenic mice that were up to 20-fold higher than those elicited by the wild-type FHbp antigen. This approach offers the potential to discover mutant antigens that might not be predictable even with protein structural information and potentially can be applied to other microbial vaccine antigens that bind host proteins.

  5. Differential extraction of tumor-specific antigens from two ultraviolet light-induced murine fibrosarcomas with the use of 1-butanol.

    Science.gov (United States)

    Simcik, W J; Kripke, M L; Sheu, T L; LeGrue, S J

    1988-12-15

    The purpose of this study was to investigate the immunobiological characteristics of the tumor-specific cell surface antigen expressed by the UV-induced murine fibrosarcoma, UV-2240. UV-2240 is classified as a regressor UV tumor because it is immunologically rejected by normal syngeneic mice but grows in immunocompromised or UV-irradiated hosts. The strong tumor-specific rejection antigen expressed by UV-2240 was found on the plasma membrane, and unlike the previously characterized antigen of UV-1591, the UV-2240 antigen was removed by using the noncytolytic butanol extraction technique. The tumor antigen activity in butanol extracts was resistant to digestion by endoglycosidase F and alpha-mannosidase, but was destroyed by pronase. In addition, the immunoprotective activity in extracts of UV-2240 was thermostable. These data demonstrate that the UV-2240-specific tumor antigen possesses physicochemical properties distinct from those of its well-characterized counterpart UV-1591.

  6. Added Value of Antigen ELISA in the Diagnosis of Neurocysticercosis in Resource Poor Settings

    Science.gov (United States)

    Dorny, Pierre; Abatih, Emmanuel Nji; Schmutzhard, Erich; Ombay, Michaeli; Mathias, Bartholomayo; Winkler, Andrea Sylvia

    2012-01-01

    Background Neurocysticercosis (NCC) is the most common cause of acquired epilepsy in Taenia solium endemic areas, primarily situated in low-income countries. Diagnosis is largely based upon the “Del Brutto diagnostic criteria” using the definitive/probable/no NCC diagnosis approach. Neuroimaging and specific T. solium cysticercosis antibody detection results are at the mainstay of this diagnosis, while antigen detection in serum has never been included. This study aimed at evaluating the addition of antigen detection as a major diagnostic criterion, especially in areas where neuroimaging is absent. Methods The B158/B60 monoclonal antibody-based enzyme-linked immunosorbent assay (ELISA) for the detection of circulating cysticercus antigen was carried out retrospectively on serum samples collected during a hospital-based study from 83 people with epilepsy (PWE) in an endemic area. Results The addition of antigen results as a major criterion allowed the correct diagnosis of definitive NCC in 10 out of 17 patients as opposed to 0/17 without antigen results in the absence of neuroimaging. A sensitivity of 100% and a specificity of 84% were determined for the diagnosis of active NCC using antigen ELISA. While the use of a higher cutoff improves the specificity of the test to 96%, it decreases its sensitivity to 83%. Conclusions In areas where neuroimaging is absent, NCC diagnosis according to the existing criteria is problematic. Taking into account its limitations for diagnosis of inactive NCC, antigen detection can be of added value for diagnosing NCC in PWE by supporting diagnostic and treatment decisions. Therefore, we recommend a revision of the “Del Brutto diagnostic criteria” for use in resource poor areas and suggest the inclusion of serum antigen detection as a major criterion. PMID:23094118

  7. Added value of antigen ELISA in the diagnosis of neurocysticercosis in resource poor settings.

    Directory of Open Access Journals (Sweden)

    Sarah Gabriël

    Full Text Available BACKGROUND: Neurocysticercosis (NCC is the most common cause of acquired epilepsy in Taenia solium endemic areas, primarily situated in low-income countries. Diagnosis is largely based upon the "Del Brutto diagnostic criteria" using the definitive/probable/no NCC diagnosis approach. Neuroimaging and specific T. solium cysticercosis antibody detection results are at the mainstay of this diagnosis, while antigen detection in serum has never been included. This study aimed at evaluating the addition of antigen detection as a major diagnostic criterion, especially in areas where neuroimaging is absent. METHODS: The B158/B60 monoclonal antibody-based enzyme-linked immunosorbent assay (ELISA for the detection of circulating cysticercus antigen was carried out retrospectively on serum samples collected during a hospital-based study from 83 people with epilepsy (PWE in an endemic area. RESULTS: The addition of antigen results as a major criterion allowed the correct diagnosis of definitive NCC in 10 out of 17 patients as opposed to 0/17 without antigen results in the absence of neuroimaging. A sensitivity of 100% and a specificity of 84% were determined for the diagnosis of active NCC using antigen ELISA. While the use of a higher cutoff improves the specificity of the test to 96%, it decreases its sensitivity to 83%. CONCLUSIONS: In areas where neuroimaging is absent, NCC diagnosis according to the existing criteria is problematic. Taking into account its limitations for diagnosis of inactive NCC, antigen detection can be of added value for diagnosing NCC in PWE by supporting diagnostic and treatment decisions. Therefore, we recommend a revision of the "Del Brutto diagnostic criteria" for use in resource poor areas and suggest the inclusion of serum antigen detection as a major criterion.

  8. 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

  9. Evidence against suppressor cell involvement in naturally acquired tolerance of a minor histocompatibility antigen

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, L.L. (Trudeau Institute, Inc., Saranac Lake, New York (USA))

    1991-06-01

    The hypothesis was investigated that suppressor cells may be responsible for maintenance of immunologic tolerance of a minor H3 antigen in mice that express the antigen naturally. Lymphoid cell populations from B6.C-H-24c (HW54) mice, a congenic-resistant strain histoincompatible with H-24b-expressing C57BL/6 (B6) mice only with respect to the H-24 locus, were examined in cell-transfer experiments to see if they contained naturally arising H-24c-specific suppressor cells. The H-24 antigen was chosen for these studies because, unlike most other minor and major histocompatibility (H) antigens, it is not detectable on mature lymphoid cells by any of several functional criteria. Thus transfer of HW54 lymphoid cells to B6 hosts could be done without the complication of inducing hyporesponsiveness de novo in the host, as occurs with other minor H antigens that are expressed on lymphocytes. B6 hosts were given HW54 skin grafts along with HW54 lymphoid cells to assess their tolerance of the H-24c-encoded antigen. The hosts were either (1) normal, nonimmune B6 mice; (2) B6 mice rendered immunodeficient by thymectomy and irradiation (TxB) and repopulated with H-24c-immune B6 lymphocytes; or (3) TxB B6 hosts repopulated with nonimmune B6 lymphocytes. In each case it was found that the additionally infused HW54 lymphoid cells did not suppress the ability of these hosts to reject HW54 skin grafts. In other words, HW54 lymphoid cells appear not to possess suppressive activity specific for the H-24c antigen that might maintain antigen-specific natural tolerance. Additional experiments were performed to determine whether HW54 lymphoid cells can inhibit the ability of sublethally irradiated B6 mice to regain the capacity to reject HW54 skin.

  10. Strain Selection for Generation of O-Antigen-Based Glycoconjugate Vaccines against Invasive Nontyphoidal Salmonella Disease.

    Directory of Open Access Journals (Sweden)

    Luisa Lanzilao

    Full Text Available Nontyphoidal Salmonellae, principally S. Typhimurium and S. Enteritidis, are a major cause of invasive bloodstream infections in sub-Saharan Africa with no vaccine currently available. Conjugation of lipopolysaccharide O-antigen to a carrier protein constitutes a promising vaccination strategy. Here we describe a rational process to select the most appropriate isolates of Salmonella as source of O-antigen for developing a bivalent glycoconjugate vaccine. We screened a library of 30 S. Typhimurium and 21 S. Enteritidis in order to identify the most suitable strains for large scale O-antigen production and generation of conjugate vaccines. Initial screening was based on growth characteristics, safety profile of the isolates, O-antigen production, and O-antigen characteristics in terms of molecular size, O-acetylation and glucosylation level and position, as determined by phenol sulfuric assay, NMR, HPLC-SEC and HPAEC-PAD. Three animal isolates for each serovar were identified and used to synthesize candidate glycoconjugate vaccines, using CRM197 as carrier protein. The immunogenicity of these conjugates and the functional activity of the induced antibodies was investigated by ELISA, serum bactericidal assay and flow cytometry. S. Typhimurium O-antigen showed high structural diversity, including O-acetylation of rhamnose in a Malawian invasive strain generating a specific immunodominant epitope. S. Typhimurium conjugates provoked an anti-O-antigen response primarily against the O:5 determinant. O-antigen from S. Enteritidis was structurally more homogeneous than from S. Typhimurium, and no idiosyncratic antibody responses were detected for the S. Enteritidis conjugates. Of the three initially selected isolates, two S. Typhimurium (1418 and 2189 and two S. Enteritidis (502 and 618 strains generated glycoconjugates able to induce high specific antibody levels with high breadth of serovar-specific strain coverage, and were selected for use in vaccine

  11. A Lipid Based Antigen Delivery System Efficiently Facilitates MHC Class-I Antigen Presentation in Dendritic Cells to Stimulate CD8+ T Cells

    Science.gov (United States)

    Maji, Mithun; Mazumder, Saumyabrata; Bhattacharya, Souparno; Choudhury, Somsubhra Thakur; Sabur, Abdus; Shadab, Md.; Bhattacharya, Pradyot; Ali, Nahid

    2016-06-01

    The most effective strategy for protection against intracellular infections such as Leishmania is vaccination with live parasites. Use of recombinant proteins avoids the risks associated with live vaccines. However, due to low immunogenicity, they fail to trigger T cell responses particularly of CD8+ cells requisite for persistent immunity. Previously we showed the importance of protein entrapment in cationic liposomes and MPL as adjuvant for elicitation of CD4+ and CD8+ T cell responses for long-term protection. In this study we investigated the role of cationic liposomes on maturation and antigen presentation capacity of dendritic cells (DCs). We observed that cationic liposomes were taken up very efficiently by DCs and transported to different cellular sites. DCs activated with liposomal rgp63 led to efficient presentation of antigen to specific CD4+ and CD8+ T cells. Furthermore, lymphoid CD8+ T cells from liposomal rgp63 immunized mice demonstrated better proliferative ability when co-cultured ex vivo with stimulated DCs. Addition of MPL to vaccine enhanced the antigen presentation by DCs and induced more efficient antigen specific CD8+ T cell responses when compared to free and liposomal antigen. These liposomal formulations presented to CD8+ T cells through TAP-dependent MHC-I pathway offer new possibilities for a safe subunit vaccine.

  12. Pseudomonas aeruginosa Cif protein enhances the ubiquitination and proteasomal degradation of the transporter associated with antigen processing (TAP) and reduces major histocompatibility complex (MHC) class I antigen presentation.

    Science.gov (United States)

    Bomberger, Jennifer M; Ely, Kenneth H; Bangia, Naveen; Ye, Siying; Green, Kathy A; Green, William R; Enelow, Richard I; Stanton, Bruce A

    2014-01-03

    Cif (PA2934), a bacterial virulence factor secreted in outer membrane vesicles by Pseudomonas aeruginosa, increases the ubiquitination and lysosomal degradation of some, but not all, plasma membrane ATP-binding cassette transporters (ABC), including the cystic fibrosis transmembrane conductance regulator and P-glycoprotein. The goal of this study was to determine whether Cif enhances the ubiquitination and degradation of the transporter associated with antigen processing (TAP1 and TAP2), members of the ABC transporter family that play an essential role in antigen presentation and intracellular pathogen clearance. Cif selectively increased the amount of ubiquitinated TAP1 and increased its degradation in the proteasome of human airway epithelial cells. This effect of Cif was mediated by reducing USP10 deubiquitinating activity, resulting in increased polyubiquitination and proteasomal degradation of TAP1. The reduction in TAP1 abundance decreased peptide antigen translocation into the endoplasmic reticulum, an effect that resulted in reduced antigen available to MHC class I molecules for presentation at the plasma membrane of airway epithelial cells and recognition by CD8(+) T cells. Cif is the first bacterial factor identified that inhibits TAP function and MHC class I antigen presentation.

  13. Pseudomonas aeruginosa Cif Protein Enhances the Ubiquitination and Proteasomal Degradation of the Transporter Associated with Antigen Processing (TAP) and Reduces Major Histocompatibility Complex (MHC) Class I Antigen Presentation*

    Science.gov (United States)

    Bomberger, Jennifer M.; Ely, Kenneth H.; Bangia, Naveen; Ye, Siying; Green, Kathy A.; Green, William R.; Enelow, Richard I.; Stanton, Bruce A.

    2014-01-01

    Cif (PA2934), a bacterial virulence factor secreted in outer membrane vesicles by Pseudomonas aeruginosa, increases the ubiquitination and lysosomal degradation of some, but not all, plasma membrane ATP-binding cassette transporters (ABC), including the cystic fibrosis transmembrane conductance regulator and P-glycoprotein. The goal of this study was to determine whether Cif enhances the ubiquitination and degradation of the transporter associated with antigen processing (TAP1 and TAP2), members of the ABC transporter family that play an essential role in antigen presentation and intracellular pathogen clearance. Cif selectively increased the amount of ubiquitinated TAP1 and increased its degradation in the proteasome of human airway epithelial cells. This effect of Cif was mediated by reducing USP10 deubiquitinating activity, resulting in increased polyubiquitination and proteasomal degradation of TAP1. The reduction in TAP1 abundance decreased peptide antigen translocation into the endoplasmic reticulum, an effect that resulted in reduced antigen available to MHC class I molecules for presentation at the plasma membrane of airway epithelial cells and recognition by CD8+ T cells. Cif is the first bacterial factor identified that inhibits TAP function and MHC class I antigen presentation. PMID:24247241

  14. Autoantibodies in autoimmune thyroid disease promote immune complex formation with self antigens and increase B cell and CD4+ T cell proliferation in response to self antigens

    DEFF Research Database (Denmark)

    Nielsen, Claus Henrik; Hegedüs, Laszlo; Leslie, Robert Graham Quinton

    2004-01-01

    B cells are centrally involved as antigen-presenting cells in certain autoimmune diseases. To establish whether autoantibodies form immune complexes (IC) with self-antigens in autoimmune thyroid disease (AITD) and promote B cell uptake of self-antigen, sera from patients with Hashimoto......'s thyroiditis (HT), Graves' disease (GD) and healthy controls were incubated with human thyroglobulin (Tg) before adding normal peripheral blood mononuclear cells. The deposition of immunoglobulins and C3 fragments on B cells was then assessed. Inclusion of Tg in serum from HT patients promoted B cell capture...... of IgG and C3 fragments. Furthermore, the binding of Tg to B cells in preparations of normal blood cells was higher in HT serum than in serum from controls and correlated positively with the serum anti-Tg activity, as did the B and CD4+ T cell proliferation. Disruption of the three-dimensional structure...

  15. Spreading the load: Antigen transfer between migratory and lymph node-resident dendritic cells promotes T-cell priming.

    Science.gov (United States)

    Mueller, Scott N

    2017-10-01

    Dendritic cells (DC) are specialized in the processing and presentation of antigen for the activation of lymphocytes. Multiple subsets of DCs exist with distinct functions and roles in the initiation of immune responses. DCs found within tissues acquire antigens or become infected by pathogens and migrate to local draining lymph nodes (LN) where they can directly stimulate T cells. These migratory DCs can also transfer antigens to LN-resident DCs and may indirectly enhance T cell priming. In this issue of the European Journal of Immunology, Gurevich et al. [Eur. J. Immunol. 2017. 47: 1802-1818] elegantly demonstrate the influence of the transfer of antigen from migratory DCs to resident DCs on the dynamics of CD8 T-cell priming in mice. Using both in vitro imaging to visualise antigen dissemination and intravital 2-photon microscopy to track T cell clustering with migratory and resident DCs, antigen-donor DC were found to efficiently distribute antigen to recipient DC. This process, which involved LFA-1, enhanced the recruitment of CD8 + T cells into the response and rescued priming when DCs were impaired in presentation capacity. Together, these findings shed light on the dynamics of the transfer of antigens between DCs in vivo for the efficient priming of cytotoxic T cell responses. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Differential Recognition and Hydrolysis of Host Carbohydrate Antigens by Streptococcus pneumoniae Family 98 Glycoside Hydrolases

    Energy Technology Data Exchange (ETDEWEB)

    Higgins, M.; Whitworth, G; El Warry, N; Randriantsoa, M; Samain, E; Burke, R; Vocadlo, D; Boraston, A

    2009-01-01

    The presence of a fucose utilization operon in the Streptococcus pneumoniae genome and its established importance in virulence indicates a reliance of this bacterium on the harvesting of host fucose-containing glycans. The identities of these glycans, however, and how they are harvested is presently unknown. The biochemical and high resolution x-ray crystallographic analysis of two family 98 glycoside hydrolases (GH98s) from distinctive forms of the fucose utilization operon that originate from different S. pneumoniae strains reveal that one enzyme, the predominant type among pneumococcal isolates, has a unique endo-{beta}-galactosidase activity on the LewisY antigen. Altered active site topography in the other species of GH98 enzyme tune its endo-{beta}-galactosidase activity to the blood group A and B antigens. Despite their different specificities, these enzymes, and by extension all family 98 glycoside hydrolases, use an inverting catalytic mechanism. Many bacterial and viral pathogens exploit host carbohydrate antigens for adherence as a precursor to colonization or infection. However, this is the first evidence of bacterial endoglycosidase enzymes that are known to play a role in virulence and are specific for distinct host carbohydrate antigens. The strain-specific distribution of two distinct types of GH98 enzymes further suggests that S. pneumoniae strains may specialize to exploit host-specific antigens that vary from host to host, a factor that may feature in whether a strain is capable of colonizing a host or establishing an invasive infection.

  17. Pseudomonas pili. Studies on antigenic determinants and mammalian cell receptors.

    Science.gov (United States)

    Paranchych, W; Sastry, P A; Drake, D; Pearlstone, J R; Smillie, L B

    1985-01-01

    P. aeruginosa PAK pili are thin 5.2 nm diameter filaments containing a single 15-kd polypeptide subunit which is 144 amino acid residues in length. Studies on pili binding to a variety of synthetic sugars representing many di- tri- and tetra-saccharide structures found in mammalian glycoproteins and glycolipids failed to reveal any significant binding activity. On the other hand, a wide spectrum of binding activities was observed when a variety of structural proteins and enzymes were used as binding substrates. Of 30 proteins tested, phosphorylase b, pyruvate kinase and aldolase showed highest pilus binding activity. It was concluded that the PAK pilus receptor is probably a polypeptide rather than an oligosaccharide. Using arginine-specific cleavage to produce four large peptides, several proteases to produce subfragments of the large peptides, and antipilus rabbit antiserum, PAK pilin was found to contain four antigenic determinants. Epitopes near the NH2- and COOH-termini were only weakly immunogenic, whereas two epitopes near the center of the pilus protein titrated about 85% of the antipilus antibodies. Cleavage of the pilus protein into smaller peptides resulted in marked decreases in the affinity of antigenic peptides for their specific antibodies, suggesting that the immunodominant epitopes of PAK pilin are conformation-specific.

  18. Review of Cancer Immunotherapy: Application of Chimeric Antigen Receptor T Cells and Programmed Death 1/Programmed Death-ligand 1 Antibodies

    OpenAIRE

    Tengfei Zhang; Ling Cao; Zhen Zhang; Dongli Yue; Yu Ping; Hong Li; Lan Huang; Yi Zhang

    2015-01-01

    Cancer immunotherapy strategies based on chimeric antigen receptor (CAR) transduced T cells or antibodies against immune checkpoints, cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) and programmed death 1 (PD-1), achieved significant successes from bench to clinic in the past 2 years. CARs are artificial engineered receptors that can specifically target tumor cell surface antigen, activate T cell and further enhance T cell function, independent of major histocompatibility complex. CAR T ...

  19. Different immunogenicity but similar antitumor efficacy of two DNA vaccines coding for an antigen secreted in different membrane vesicle-associated forms

    OpenAIRE

    Bellier, Bertrand; Sedlik, Christine; Vigneron, James; Torrieri-Dramard, Lea; Pitoiset, Fabien; Denizeau, Jordan; Chesneau, Caroline; de la Rochere, Philippe; Lantz, Olivier; Thery, Clotilde

    2014-01-01

    The induction of an active immune response to control or eliminate tumours is still an unfulfilled challenge. We focused on plasmid DNA vaccines using an innovative approach whereby the antigen is expressed in association with extracellular vesicles (EVs) to facilitate antigen cross-presentation and improve induced immunity. Our two groups had independently shown previously that DNA vaccines encoding EV-associated antigens are more efficient at inducing cytotoxic T-cell responses than vaccine...

  20. Phenotype and functional evaluation of ex vivo generated antigen-specific immune effector cells with potential for therapeutic applications

    Science.gov (United States)

    Han, Shuhong; Huang, Yuju; Liang, Yin; Ho, Yuchin; Wang, Yichen; Chang, Lung-Ji

    2009-01-01

    Ex vivo activation and expansion of lymphocytes for adoptive cell therapy has demonstrated great success. To improve safety and therapeutic efficacy, increased antigen specificity and reduced non-specific response of the ex vivo generated immune cells are necessary. Here, using a complete protein-spanning pool of pentadecapeptides of the latent membrane protein 2A (LMP2A) of Epstein-Barr virus (EBV), a weak viral antigen which is associated with EBV lymphoproliferative diseases, we investigated the phenotype and function of immune effector cells generated based on IFN-γ or CD137 activation marker selection and dendritic cell (DC) activation. These ex vivo prepared immune cells exhibited a donor- and antigen-dependent T cell response; the IFN-γ-selected immune cells displayed a donor-related CD4- or CD8-dominant T cell phenotype; however, the CD137-enriched cells showed an increased ratio of CD4 T cells. Importantly, the pentadecapeptide antigens accessed both class II and class I MHC antigen processing machineries and effectively activated EBV-specific CD4 and CD8 T cells. Phenotype and kinetic analyses revealed that the IFN-γ and the CD137 selections enriched more central memory T (Tcm) cells than did the DC-activation approach, and after expansion, the IFN-γ-selected effector cells showed the highest level of antigen-specificity and effector activities. While all three approaches generated immune cells with comparable antigen-specific activities, the IFN-γ selection followed by ex vivo expansion produced high quality and quantity of antigen-specific effector cells. Our studies presented the optimal approach for generating therapeutic immune cells with potential for emergency and routine clinical applications. PMID:19660111

  1. Multiple sclerosis: Skin-induced antigen-specific immune tolerance.

    Science.gov (United States)

    Wildner, Paula; Selmaj, Krzysztof W

    2017-10-15

    Multiple sclerosis (MS) is a highly prevalent demyelinating disorder, presumed to be driven by an autoimmune response toward the central nervous system (CNS) components. All currently available treatments modulate the immune system globally and besides the reduction of disease activity, they may also impose considerable disturbances on the immune protective mechanisms. Thus, induction of antigen-specific immune tolerance remains the ultimate goal of MS therapy. Such approach carries promising therapeutic perspectives and, above all, a desirable safety profile. Several studies have been performed to evaluate highly selective, antigen-induced, therapies for experimental autoimmune encephalomyelitis (EAE) and MS. These trials have also indicated the importance of the antigen administration route. The continued efforts to develop efficient and safe MS therapy gave rise to the idea of incorporating the skin immune system in order to modulate autoimmunity in MS. Skin is the largest immunological organ of human body, and thus provides ample opportunities to modify immune responses. Skin dendritic cells have a significant ability to modulate the immune reactions, promoting either immunity or tolerance. Their capacity to induce tolerance has already been described in several experimental models of MS. In a one-year, double-blinded, placebo-controlled study assessing the effectiveness of transdermal myelin peptides patches, significant changes in the morphology of Langerhans cells (LCs) and shifts in the dendritic cell (DC) populations in the draining lymph nodes have been observed. In addition, patients treated with myelin patches showed a decreased brain inflammatory activity on MRI and a reduced relapse rate. In this review, we further discuss the potential to use skin-induced immune tolerance for MS treatment, with a particular focus on dermal DCs. Copyright © 2017. Published by Elsevier B.V.

  2. Solid nanoemulsion as antigen and immunopotentiator carrier for transcutaneous immunization.

    Science.gov (United States)

    Gogoll, Karsten; Stein, Pamela; Lee, K D; Arnold, Philipp; Peters, Tanja; Schild, Hansjörg; Radsak, Markus; Langguth, Peter

    2016-10-01

    Imiquimod, a toll-like receptor 7 (TLR7) agonist, is an active pharmaceutical ingredient (API) established for the topical treatment of several dermal cancerous and precancerous skin lesions. Within this work, the immunostimulatory effect of imiquimod is further exploited in a transcutaneous immunization (TCI) approach based on a solid nanoemulsion (SN) formulation. SN contains a combination of imiquimod with the model peptide antigen SIINFEKL as a novel approach to omit needle and syringe and optimize dermal antigen administration. Excipients including sucrose fatty acid esters and the pharmaceutically acceptable oils MCT (middle chain triglycerides), avocado oil, jojoba wax and squalene are high pressure homogenized together with the antigen SIINFEKL. Freeze drying was performed to eliminate water and to achieve spreadable properties of the formulation for dermal administration. The influence of the different oil components was assessed regarding in vitro drug permeation in a Franz diffusion cell model using a murine skin setup. In vivo performance in terms of cytotoxic T-cell response was assessed in a C57BL/6 mouse model. Whereas Aldara® cream contains imiquimod in a dissolved state, the SN formulations carry the active in a suspended state. This resulted in a reduction of imiquimod permeation across murine skin from the SN when compared to Aldara® cream. In spite of this permeation rate reduction, each SN induced an in vivo immune response by specific T-cell lysis. A stabilized solid nanosuspension containing squalene/tocopherol exhibited a significantly higher performance (p⩽0.05) in comparison with Aldara® cream. MCT based SN exerted an in vivo effect comparable to Aldara®. In conclusion, anhydrous highly dispersed vehicles containing imiquimod in a submicron particle size distribution can represent promising formulations for TCI. The choice of the oil component has a strong influence on SN performance, independent of in vitro drug permeation

  3. Bidirectional interactions between antigen-bearing respiratory tract dendritic cells (DCs) and T cells precede the late phase reaction in experimental asthma: DC activation occurs in the airway mucosa but not in the lung parenchyma

    National Research Council Canada - National Science Library

    Huh, Joong C; Strickland, Deborah H; Jahnsen, Frode L; Turner, Debra J; Thomas, Jenny A; Napoli, Sylvia; Tobagus, Iriani; Stumbles, Philip A; Sly, Peter D; Holt, Patrick G

    2003-01-01

    ...(s) underlying transient T cell activation during this inflammatory response is unclear. We present evidence that this response is regulated via bidirectional interactions between airway mucosal dendritic cells (AMDC) and T memory cells...

  4. Cytotoxicity of Tumor Antigen Specific Human T Cells Is Unimpaired by Arginine Depletion

    Science.gov (United States)

    Knies, Diana; Medenhoff, Sergej; Wabnitz, Guido; Luckner-Minden, Claudia; Feldmeyer, Nadja; Voss, Ralf-Holger; Kropf, Pascale; Müller, Ingrid; Conradi, Roland; Samstag, Yvonne; Theobald, Matthias; Ho, Anthony D.; Goldschmidt, Hartmut; Hundemer, Michael

    2013-01-01

    Tumor-growth is often associated with the expansion of myeloid derived suppressor cells that lead to local or systemic arginine depletion via the enzyme arginase. It is generally assumed that this arginine deficiency induces a global shut-down of T cell activation with ensuing tumor immune escape. While the impact of arginine depletion on polyclonal T cell proliferation and cytokine secretion is well documented, its influence on chemotaxis, cytotoxicity and antigen specific activation of human T cells has not been demonstrated so far. We show here that chemotaxis and early calcium signaling of human T cells are unimpaired in the absence of arginine. We then analyzed CD8+ T cell activation in a tumor peptide as well as a viral peptide antigen specific system: (i) CD8+ T cells with specificity against the MART-1aa26–35*A27L tumor antigen expanded with in vitro generated dendritic cells, and (ii) clonal CMV pp65aa495–503 specific T cells and T cells retrovirally transduced with a CMV pp65aa495–503 specific T cell receptor were analyzed. Our data demonstrate that human CD8+ T cell antigen specific cytotoxicity and perforin secretion are completely preserved in the absence of arginine, while antigen specific proliferation as well as IFN-γ and granzyme B secretion are severely compromised. These novel results highlight the complexity of antigen specific T cell activation and demonstrate that human T cells can preserve important activation-induced effector functions in the context of arginine deficiency. PMID:23717444

  5. Cytotoxicity of tumor antigen specific human T cells is unimpaired by arginine depletion.

    Directory of Open Access Journals (Sweden)

    Markus Munder

    Full Text Available Tumor-growth is often associated with the expansion of myeloid derived suppressor cells that lead to local or systemic arginine depletion via the enzyme arginase. It is generally assumed that this arginine deficiency induces a global shut-down of T cell activation with ensuing tumor immune escape. While the impact of arginine depletion on polyclonal T cell proliferation and cytokine secretion is well documented, its influence on chemotaxis, cytotoxicity and antigen specific activation of human T cells has not been demonstrated so far. We show here that chemotaxis and early calcium signaling of human T cells are unimpaired in the absence of arginine. We then analyzed CD8(+ T cell activation in a tumor peptide as well as a viral peptide antigen specific system: (i CD8(+ T cells with specificity against the MART-1aa26-35*A27L tumor antigen expanded with in vitro generated dendritic cells, and (ii clonal CMV pp65aa495-503 specific T cells and T cells retrovirally transduced with a CMV pp65aa495-503 specific T cell receptor were analyzed. Our data demonstrate that human CD8(+ T cell antigen specific cytotoxicity and perforin secretion are completely preserved in the absence of arginine, while antigen specific proliferation as well as IFN-γ and granzyme B secretion are severely compromised. These novel results highlight the complexity of antigen specific T cell activation and demonstrate that human T cells can preserve important activation-induced effector functions in the context of arginine deficiency.

  6. CARbodies: Human Antibodies Against Cell Surface Tumor Antigens Selected From Repertoires Displayed on T Cell Chimeric Antigen Receptors

    Directory of Open Access Journals (Sweden)

    Vanesa Alonso-Camino

    2013-01-01

    Full Text Available A human single-chain variable fragment (scFv antibody library was expressed on the surface of human T cells after transduction with lentiviral vectors (LVs. The repertoire was fused to a first-generation T cell receptor ζ (TCRζ-based chimeric antigen receptor (CAR. We used this library to isolate antibodies termed CARbodies that recognize antigens expressed on the tumor cell surface in a proof-of-principle system. After three rounds of activation-selection there was a clear repertoire restriction, with the emergence dominant clones. The CARbodies were purified from bacterial cultures as soluble and active proteins. Furthermore, to validate its potential application for adoptive cell therapy, human T cells were transduced with a LV encoding a second-generation costimulatory CAR (CARv2 bearing the selected CARbodies. Transduced human primary T cells expressed significant levels of the CARbodies-based CARv2 fusion protein on the cell surface, and importantly could be specifically activated, after stimulation with tumor cells. This approach is a promising tool for the generation of antibodies fully adapted to the display format (CAR and the selection context (cell synapse, which could extend the scope of current adoptive cell therapy strategies with CAR-redirected T cells.

  7. 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.

  8. How the immune system detects lipid antigens.

    Science.gov (United States)

    De Libero, Gennaro; Mori, Lucia

    2010-04-01

    T lymphocytes are the cells of the immune system that may recognize glycolipids as antigens. T cells recognize lipids associated with the non-polymorphic molecules of the CD1 family present on the membrane of antigen-presenting cells. CD1 molecules contain hydrophobic pockets, which bind a large variety of lipid molecules in various manners. Lipid antigenicity is determined by their mode of uptake, membrane trafficking properties, degradation within endosomal compartments and capacity to form stable complexes with CD1. Extracellular and intracellular lipid binding proteins participate in lipid handling and loading on CD1 molecules within antigen-presenting cells. Recent crystal structures have disclosed how the T cell receptor contacts CD1-lipid complexes, revealing the contribution of both CD1 and lipid residues in making functionally relevant contacts. Lipid-specific T cells are important in autoimmunity, cancer surveillance, protection during infections, and in immunoregulation. The immunogenicity of lipids is being exploited in novel approaches to immunotherapy, including inhibition of autoimmunity and anti-cancer and bacterial vaccines. Copyright 2009. Published by Elsevier Ltd.

  9. 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.

  10. Evaluation of an Antigen-Antibody

    African Journals Online (AJOL)

    GB

    detect samples with high viral loads have a significant implication for this assay designed to detect both antigen and antibody proteins. Arguably, HCV as a member of Flaviviridae family has an icosahedral capsid of T3 or T4 symmetry with 180 or 240 core protein subunits. Since one RNA genome contains 240 subunits of.

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

    African Journals Online (AJOL)

    Yomi

    2012-01-31

    Jan 31, 2012 ... Key word: Hyaluronidase gene, cloning, expression of recombinant gene, antigenic region. INTRODUCTION. Group A streptococcus (Streptococcus pyogenes) is an important species of gram-positive pathogenic extra- cellular bacteria. This bacteria can produce wide range of infectious diseases like ...

  12. Antigenic characterisation of lyssaviruses in South Africa

    Directory of Open Access Journals (Sweden)

    Ernest Ngoepe

    2014-02-01

    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.

  13. Preparation and characterization of antigenic properties of ...

    African Journals Online (AJOL)

    PRECIOUS

    2009-12-15

    Dec 15, 2009 ... maleimidomethyl) cyclohexane-1-carboxylic acid 3-sulfo-N-hydroxysuccinimide ester sodium salt. (sulfo-SMCC) to form disulfide linkage. In order to obtain artificial antigen of GA, GA was linked to KLH and OVA by sulfo-SMCC coupling at room temperature. The conjugates of KLH-Peptide and OVA-.

  14. [Presence of Australia antigen in blood donors].

    Science.gov (United States)

    Gota, F

    1980-01-01

    The differential diagnosis of type A and B viral hepatitis is discussed and guidelines for the prevention of post-transfusional hospital hepatitis are proposed. Methods for the immunological demonstration of HBs antigen are illustrated, together with the respective positivity percentages in blood donors.

  15. Bordetella bronchiseptica antigen enhances the production of Mycoplasma hyopneumoniae antigen-specific immunoglobulin G in mice.

    Science.gov (United States)

    Yim, Seol-Hwa; Hahn, Tae-Wook; Joo, Hong-Gu

    2017-09-30

    We previously demonstrated that Bordetella (B.) bronchiseptica antigen (Ag) showed high immunostimulatory effects on mouse bone marrow cells (BMs) while Mycoplasma (M.) hyopneumoniae Ag showed low effects. The focus of this study was to determine if B. bronchiseptica Ag can enhance the M. hyopneumoniae Ag-specific immune response and whether the host's immune system can recognize both Ags. MTT assay results revealed that each or both Ags did not significantly change BM metabolic activity. Flow cytometry analysis using carboxyfluorescein succinimidyl ester showed that B. bronchiseptica Ag can promote the division of BMs. In cytokine and nitric oxide (NO) assays, B. bronchiseptica Ag boosted production of tumor necrosis factor-alpha in M. hyopneumoniae Ag-treated BMs, and combined treatment with both Ags elevated the level of NO in BMs compared to that from treatment of M. hyopneumoniae Ag alone. Immunoglobulin (Ig)G enzyme-linked immunosorbent assay using the sera of Ag-injected mice clearly indicated that B. bronchiseptica Ag can increase the production of M. hyopneumoniae Ag-specific IgG. This study provided information valuable in the development of M. hyopneumoniae vaccines and showed that B. bronchiseptica Ag can be used both as a vaccine adjuvant and as a vaccine Ag.

  16. Identification and characterization of a putative agglutination/immobilization antigen on the surface of Cryptocaryon irritans.

    Science.gov (United States)

    Hatanaka, A; Umeda, N; Yamashita, S; Hirazawa, N

    2007-08-01

    The ciliated protozoan Cryptocaryon irritans, a parasite of seawater fishes, was found to express an antigen that elicits antibodies in rabbits and tiger puffer (Takifugu ruburipes). Serum from rabbits and fish immunized with theronts had agglutination/immobilization activity against theronts in vitro; fish serum antibody levels (measured by enzyme-linked immunosorbent assays: ELISA) correlated with this activity. Anti-theront antibody levels in fish were significantly higher in the immunized group as compared with control fish at 2 weeks after booster immunization (injection of bovine serum albumin; Student's t-test, P<0.01). Biochemical analyses indicated that a Triton X-114-soluble 32 kDa theront integral membrane protein may be the agglutination/immobilization antigen. Indirect immunofluorescence staining of theronts suggested that this 32 kDa antigen was expressed on the surface of cilia. The full-length 32 kDa antigen cDNA contained 1147 basepairs, encoding a 328-amino acid protein including hydrophobic N- and C-termini. As with Tetrahymena and Paramecium spp., TAA and TAG appear to be used as glutamine codons in the 32 kDa antigen gene.

  17. Measurement of phenotype and absolute number of circulating heparin-binding hemagglutinin, ESAT-6 and CFP-10, and purified protein derivative antigen-specific CD4 T cells can discriminate active from latent tuberculosis infection.

    Science.gov (United States)

    Hutchinson, Paul; Barkham, Timothy M S; Tang, Wenying; Kemeny, David M; Chee, Cynthia Bin-Eng; Wang, Yee T

    2015-02-01

    The tuberculin skin test (TST) and interferon gamma (IFN-γ) release assays (IGRAs) are used as adjunctive tests for the evaluation of suspected cases of active tuberculosis (TB). However, a positive test does not differentiate latent from active TB. We investigated whether flow cytometric measurement of novel combinations of intracellular cytokines and surface makers on CD4 T cells could differentiate between active and latent TB after stimulation with Mycobacterium tuberculosis-specific proteins. Blood samples from 60 patients referred to the Singapore Tuberculosis Control Unit for evaluation for active TB or as TB contacts were stimulated with purified protein derivative (PPD), ESAT-6 and CFP-10, or heparin-binding hemagglutinin (HBHA). The CD4 T cell cytokine response (IFN-γ, interleukin-2 [IL-2], interleukin-17A [IL-17A], interleukin-22 [IL-22], granulocyte-macrophage colony-stimulating factor [GM-CSF], and tumor necrosis factor alpha [TNF-α]) and surface marker expression (CD27, CXCR3, and CD154) were then measured. We found that the proportion of PPD-specific CD4 T cells, defined as CD154(+) TNF-α(+) cells that were negative for CD27 and positive for GM-CSF, gave the strongest discrimination between subjects with latent and those with active TB (area under the receiver operator characteristic [ROC] curve of 0.9277; P CFP-10-responding to HBHA-responding CD4 T cells was significantly different between the two study populations. In conclusion, we found novel markers of M. tuberculosis-specific CD4 cells which differentiate between active and latent TB. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  18. Carbohydrate antigen 125 and carcinoembryonic antigen in the differentiation of tuberculous peritonitis and peritonitis carcinomatosa

    OpenAIRE

    Tong, Huan; Tai, Yang; Ye, Cheng; Wu, Hao; Zhang, Lin-Hao; Gao, Jin-Hang; Yan, Zhao-Ping; Huang, Zhi-Yin; Tang, Cheng-Wei

    2017-01-01

    Tumor markers could increase in both tuberculous peritonitis and peritonitis carcinomatosa, confusing the differentiation of these diseases. This study aimed to better understand the extent of elevation and diagnostic efficacies of carbohydrate antigen 125 (CA 125), carcinoembryonic antigen (CEA) and combinative use of them in tuberculous peritonitis and peritonitis carcinomatosa. Of 2998 patients reviewed, 101, 120 and 71 patients were assigned to TBP group (tuberculous peritonitis), non-OCA...

  19. CA 19-9 (Cancer Antigen 19-9)

    Science.gov (United States)

    ... called Lewis antigen that is similar to the ABO antigens that are used in blood typing for ... Guidelines for the Use of Tumor Markers in Breast and Colorectal Cancer [On-line guidelines]. Available online at http://www. ...

  20. 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

  1. Identification of potential antigenic proteins of Theileria lestoquardi.

    Science.gov (United States)

    Bakheit, Mohammed; Scholzen, Thomas; Ahmed, Jabbar S; Seitzer, Ulrike

    2006-10-01

    A PCR strategy was used to identify potential antigenic proteins of T. lestoquardi suitable for the development of an ELISA by searching for homologous proteins previously identified in other theilierial parasites to be antigenic.

  2. 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....

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

    NARCIS (Netherlands)

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

    2004-01-01

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

  4. Characterization of an enterobacterial common antigen (ECA) epitope recognized by anti-ECA-tetanus toxoid conjugate serum.

    Science.gov (United States)

    Lugowski, C; Romanowska, E

    1991-01-15

    The antigenic reactivity of both native and chemically modified enterobacterial common antigen (ECA) with anti-ECA-tetanus toxoid (TT) conjugate serum was investigated. The results obtained suggest that reduction of the carboxyl group of the mannosaminuronic acid component of ECA diminishes, but does not destroy its antigenic reactivity. Each of the sugar components were found to contribute to its reactivity with anti-ECA-TT conjugate serum, indicating that the trisaccharide repeating unit represents the ECA epitope. A nonasaccharide (trimer of the ECA repeating unit) inhibited antibody binding better than the hexasaccharide dimer, a finding which suggests that oligosaccharide conformation also makes a contribution to its inhibitory activity.

  5. Comparison of Schistosoma mansoni soluble cercarial antigens and soluble egg antigens for serodiagnosing schistosome infections.

    Science.gov (United States)

    Smith, Huw; Doenhoff, Mike; Aitken, Cara; Bailey, Wendi; Ji, Minjun; Dawson, Emily; Gilis, Henk; Spence, Grant; Alexander, Claire; van Gool, Tom

    2012-01-01

    A Schistosoma mansoni cercarial antigen preparation (cercarial transformation fluid--SmCTF) was evaluated for detection of anti-schistosome antibodies in human sera in 4 collaborating laboratories. The performance of SmCTF was compared with that of S. mansoni egg antigens (SmSEA) in an indirect enzyme-immunoassay (ELISA) antigen assay, the latter being used routinely in 3 of the 4 participating laboratories to diagnose S. mansoni and S. haematobium infections. In the fourth laboratory the performance of SmCTF was compared with that of S. japonicum egg antigens (SjSEA) in ELISA for detection of anti-S. japonicum antibodies. In all 4 laboratories the results given by SmCTF in ELISA were very similar to those given by the antigen preparation routinely used in the respective laboratory to detect anti-schistosome antibodies in human infection sera. In so far as the ELISA results from SmCTF are thus so little different from those given by schistosome egg antigens and also cheaper to produce, the former is a potentially useful new diagnostic aid for schistosomiasis.

  6. Comparison of Schistosoma mansoni soluble cercarial antigens and soluble egg antigens for serodiagnosing schistosome infections.

    Directory of Open Access Journals (Sweden)

    Huw Smith

    Full Text Available A Schistosoma mansoni cercarial antigen preparation (cercarial transformation fluid--SmCTF was evaluated for detection of anti-schistosome antibodies in human sera in 4 collaborating laboratories. The performance of SmCTF was compared with that of S. mansoni egg antigens (SmSEA in an indirect enzyme-immunoassay (ELISA antigen assay, the latter being used routinely in 3 of the 4 participating laboratories to diagnose S. mansoni and S. haematobium infections. In the fourth laboratory the performance of SmCTF was compared with that of S. japonicum egg antigens (SjSEA in ELISA for detection of anti-S. japonicum antibodies. In all 4 laboratories the results given by SmCTF in ELISA were very similar to those given by the antigen preparation routinely used in the respective laboratory to detect anti-schistosome antibodies in human infection sera. In so far as the ELISA results from SmCTF are thus so little different from those given by schistosome egg antigens and also cheaper to produce, the former is a potentially useful new diagnostic aid for schistosomiasis.

  7. Kinetics of human T-cell expression of LFA-1, IL-2 receptor, and ICAM-1 following antigenic stimulation in vitro

    DEFF Research Database (Denmark)

    Hviid, L; Felsing, A; Theander, T G

    1993-01-01

    Numerous studies have examined kinetics of T-cell functional responses following non-specific and antigen-specific stimulation in vitro. However, while reports of phenotypic T-cell changes after non-specific stimulation are abundant, only little information on phenotypic effects of antigen......-specific stimulation is available. In the present study we have examined phenotypic T-cell changes after in vitro stimulation by the antigens purified derivative of tuberculin (PPD) and tetanus toxoid (TT). We show that the well-established differences in kinetics of mitogen- and antigen-induced T-cell proliferation...... in vitro is paralleled by differential kinetics in the expression of the T-cell adhesion and activation antigens leukocyte function-associated antigen 1 (LFA-1; CD11a/CD18), interleukin-2 receptor (IL-2R; CD25), and intercellular adhesion molecule 1 (ICAM-1; CD54). Furthermore, the changes in expression...

  8. 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

  9. 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...

  10. 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.

  11. Immunity to Intracellular Salmonella Depends on Surface-associated Antigens

    Science.gov (United States)

    Claudi, Beatrice; Mazé, Alain; Schemmer, Anne K.; Kirchhoff, Dennis; Schmidt, Alexander; Burton, Neil; Bumann, Dirk

    2012-01-01

    Invasive Salmonella infection is an important health problem that is worsening because of rising antimicrobial resistance and changing Salmonella serovar spectrum. Novel vaccines with broad serovar coverage are needed, but suitable protective antigens remain largely unknown. Here, we tested 37 broadly conserved Salmonella antigens in a mouse typhoid fever model, and identified antigen candidates that conferred partial protection against lethal disease. Antigen properties such as high in vivo abundance or immunodominance in convalescent individuals were not required for protectivity, but all promising antigen candidates were associated with the Salmonella surface. Surprisingly, this was not due to superior immunogenicity of surface antigens compared to internal antigens as had been suggested by previous studies and novel findings for CD4 T cell responses to model antigens. Confocal microscopy of infected tissues revealed that many live Salmonella resided alone in infected host macrophages with no damaged Salmonella releasing internal antigens in their vicinity. In the absence of accessible internal antigens, detection of these infected cells might require CD4 T cell recognition of Salmonella surface-associated antigens that could be processed and presented even from intact Salmonella. In conclusion, our findings might pave the way for development of an efficacious Salmonella vaccine with broad serovar coverage, and suggest a similar crucial role of surface antigens for immunity to both extracellular and intracellular pathogens. PMID:23093937

  12. Working together: interactions between vaccine antigens and adjuvants

    OpenAIRE

    Fox, Christopher B.; Kramer, Ryan M.; Barnes V, Lucien; Dowling, Quinton M.; Vedvick, Thomas S.

    2013-01-01

    The development of vaccines containing adjuvants has the potential to enhance antibody and cellular immune responses, broaden protective immunity against heterogeneous pathogen strains, enable antigen dose sparing, and facilitate efficacy in immunocompromised populations. Nevertheless, the structural interplay between antigen and adjuvant components is often not taken into account in the published literature. Interactions between antigen and adjuvant formulations should be well characterized ...

  13. 21 CFR 866.3402 - Plasmodium species antigen detection assays.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Plasmodium species antigen detection assays. 866... Plasmodium species antigen detection assays. (a) Identification. A Plasmodium species antigen detection assay... malaria caused by the four malaria species capable of infecting humans: Plasmodium falciparum, Plasmodium...

  14. 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...... antigen vaccines may be a useful approach for treating cancer....

  15. Increased expression of activation antigens on CD8+ T lymphocytes in Myalgic Encephalomyelitis/chronic fatigue syndrome: inverse associations with lowered CD19+ expression and CD4+/CD8+ ratio, but no associations with (auto)immune, leaky gut, oxidative and nitrosative stress biomarkers.

    Science.gov (United States)

    Maes, Michael; Bosmans, Eugene; Kubera, Marta

    2015-01-01

    There is now evidence that specific subgroups of patients with Myalgic Encephalomyelitis / chronic fatigue syndrome (ME/CFS) suffer from a neuro-psychiatric-immune disorder. This study was carried out to delineate the expression of the activation markers CD38 and human leukocyte antigen (HLA) DR on CD4+ and CD8+ peripheral blood lymphocytes in ME/CFS. Proportions and absolute numbers of peripheral lymphocytes expressing CD3+, CD19+, CD4+, CD8+, CD38+ and HLA-DR+ were measured in ME/CFS (n=139), chronic fatigue (CF, n=65) and normal controls (n=40). The proportions of CD3+, CD8+, CD8+CD38+ and CD8+HLA-DR+ were significantly higher in ME/CFS patients than controls, while CD38+, CD8+CD38+, CD8+HLA-DR+ and CD38+HLA-DR+ were significantly higher in ME/CFS than CF. The percentage of CD19+ cells and the CD4+/CD8+ ratio were significantly lower in ME/CFS and CF than in controls. There were highly significant inverse correlations between the increased expression of CD38+, especially that of CD8+CD38+, and the lowered CD4+/CD8+ ratio and CD19+ expression. There were no significant associations between the flow cytometric results and severity or duration of illness and peripheral blood biomarkers of oxidative and nitrosative stress (O&NS, i.e. IgM responses to O&N modified epitopes), leaky gut (IgM or IgA responses to LPS of gut commensal bacteria), cytokines (interleukin-1, tumor necrosis factor-α), neopterin, lysozyme and autoimmune responses to serotonin. The results support that a) increased CD38 and HLA-DR expression on CD8+ T cells are biomarkers of ME/CFS; b) increased CD38 antigen expression may contribute to suppression of the CD4+/CD8+ ratio and CD19+ expression; c) there are different immune subgroups of ME/CFS patients, e.g. increased CD8+ activation marker expression versus inflammation or O&NS processes; and d) viral infections or reactivation may play a role in a some ME/CFS patients.

  16. Comparison of antigen-specific T-cell responses of tuberculosis patients using complex or single antigens of Mycobacterium tuberculosis

    DEFF Research Database (Denmark)

    Mustafa, A S; Amoudy, H A; Wiker, H G

    1998-01-01

    as the vaccine strain, Mycobacterium bovis bacillus Calmette-Guerin (BCG). In addition, M. tuberculosis and MT-CF-induced T-cell lines were tested in the same assays against the panel of purified and complex antigens. The compiled data from PBMC and T-cell lines tested for antigen-induced proliferation and IFN......GroES, rPstS, rGroEL and rDnaK) antigens of Mycobacterium tuberculosis. The responses of PBMC to these defined antigens were compared with the corresponding results obtained with complex antigens, such as whole-cell M. tuberculosis, M. tuberculosis culture filtrate (MT-CF) and cell wall antigens, as well....... tuberculosis, MT-CF and M. bovis BCG. We also observed that most of the high responders to complex antigens recognized all of the antigens tested (covariation), demonstrating that the repertoire of human T-cell specificities induced by natural infection is directed towards several unrelated culture filtrate...

  17. Structure-function relationships of the antigenicity of mycolic acids in tuberculosis patients.

    Science.gov (United States)

    Beukes, Mervyn; Lemmer, Yolandy; Deysel, Madrey; Al Dulayymi, Juma'a R; Juma'a, R Al Dulayymi; Baird, Mark S; Mark, S Baird; Koza, Gani; Iglesias, Maximiliano M; Maximiliano, M Iglesias; Rowles, Richard R; Richard, R Rowles; Theunissen, Cornelia; Grooten, Johan; Toschi, Gianna; Roberts, Vanessa V; Vanessa, V Roberts; Pilcher, Lynne; Van Wyngaardt, Sandra; Mathebula, Nsovo; Balogun, Mohammed; Stoltz, Anton C; Anton, C Stoltz; Verschoor, Jan A

    2010-11-01

    Cell wall mycolic acids (MA) from Mycobacterium tuberculosis (M.tb) are CD1b presented antigens that can be used to detect antibodies as surrogate markers of active TB, even in HIV coinfected patients. The use of the complex mixtures of natural MA is complicated by an apparent antibody cross-reactivity with cholesterol. Here firstly we report three recombinant monoclonal scFv antibody fragments in the chicken germ-line antibody repertoire, which demonstrate the possibilities for cross-reactivity: the first recognized both cholesterol and mycolic acids, the second mycolic acids but not cholesterol, and the third cholesterol but not mycolic acids. Secondly, MA structure is experimentally interrogated to try to understand the cross-reactivity. Unique synthetic mycolic acids representative of the three main functional classes show varying antigenicity against human TB patient sera, depending on the functional groups present and on their stereochemistry. Oxygenated (methoxy- and keto-) mycolic acid was found to be more antigenic than alpha-mycolic acids. Synthetic methoxy-mycolic acids were the most antigenic, one containing a trans-cyclopropane apparently being somewhat more antigenic than the natural mixture. Trans-cyclopropane-containing keto- and hydroxy-mycolic acids were also found to be the most antigenic among each of these classes. However, none of the individual synthetic mycolic acids significantly and reproducibly distinguished the pooled serum of TB positive patients from that of TB negative patients better than the natural mixture of MA. This argues against the potential to improve the specificity of serodiagnosis of TB with a defined single synthetic mycolic acid antigen from this set, although sensitivity may be facilitated by using a synthetic methoxy-mycolic acid. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  18. Antigenic profiling of yersinia pestis infection in the Wyoming coyote (Canis latrans).

    Science.gov (United States)

    Vernati, G; Edwards, W H; Rocke, T E; Little, S F; Andrews, G P

    2011-01-01

    Although Yersinia pestis is classified as a "high-virulence" pathogen, some host species are variably susceptible to disease. Coyotes (Canis latrans) exhibit mild, if any, symptoms during infection, but antibody production occurs postinfection. This immune response has been reported to be against the F1 capsule, although little subsequent characterization has been conducted. To further define the nature of coyote humoral immunity to plague, qualitative serology was conducted to assess the antiplague antibody repertoire. Humoral responses to six plasmid-encoded Y. pestis virulence factors were first examined. Of 20 individual immune coyotes, 90% were reactive to at least one other antigen in the panel other than F1. The frequency of reactivity to low calcium response plasmid (pLcr)-encoded Yersinia protein kinase A (YpkA) and Yersinia outer protein D (YopD) was significantly greater than that previously observed in a murine model for plague. Additionally, both V antigen and plasminogen activator were reactive with over half of the serum samples tested. Reactivity to F1 was markedly less frequent in coyotes (35%). Twenty previously tested antibody-negative samples were also examined. While the majority were negative across the panel, 15% were positive for 1-3 non-F1 antigens. In vivo-induced antigen technology employed to identify novel chromosomal genes of Y. pestis that are up-regulated during infection resulted in the identification of five proteins, including a flagellar component (FliP) that was uniquely reactive with the coyote serum compared with immune serum from two other host species. Collectively, these data suggest that humoral immunity to pLcr-encoded antigens and the pesticin plasmid (pPst)-encoded Pla antigen may be relevant to plague resistance in coyotes. The serologic profile of Y. pestis chromosomal antigens up-regulated in vivo specific to C. latrans may provide insight into the differences in the pathogen-host responses during Y. pestis infection.

  19. Immunoproteomic identification of antigenic salivary biomarkers detected by Ixodes ricinus-exposed rabbit sera.

    Science.gov (United States)

    Vu Hai, Vinh; Pages, Frédéric; Boulanger, Nathalie; Audebert, Stéphane; Parola, Philippe; Almeras, Lionel

    2013-09-01

    Ixodes ricinus, the primary vector of tick-borne disease in Europe, is currently expanding its distribution area and its activity in many countries. Antibody responses to tick salivary antigens have been proposed as an alternative marker of exposure to tick bites. However, the identification of the I. ricinus corresponding antigens remains elusive. Using rabbits artificially exposed to I. ricinus and 2 other European tick species (Rhipicephalus sanguineus and Dermacentor reticulatus) as controls, a cross-comparison of IgG profiles was performed against protein salivary gland extracts (pSGE) from these 3 tick species using immunoblots. Immunoblot analysis highlighted a singularity in the immune patterns according to tick species exposure and pSGE antigen source. Two protein bands were detected against I. ricinus pSGE only in rabbits exposed to I. ricinus bites. An immunoproteomic approach based on a fluorescence detection method was developed to unambiguously identify corresponding antigenic spots on 2-D gels. Among the unique I. ricinus salivary antigenic proteins detected by sera from rabbits exposed to this tick species, I. ricinus calreticulin was identified. Although tick calreticulin was previously proposed as a potential antigenic marker following exposure to ticks (particularly in North American tick species), the present study suggested that Ixodes calreticulin does not appear to be cross-recognized by the 2 other tick genera tested. Additional experiments are needed to confirm the use of I. ricinus calreticulin salivary protein as a potential discriminant antigenic biomarker to Ixodes tick exposure. Copyright © 2013 Elsevier GmbH. All rights reserved.

  20. Antigenic profiling of Yersinia pestis infection in the Wyoming coyote (Canis latrans)

    Science.gov (United States)

    Vernati, G.; Edwards, W.H.; Rocke, T.E.; Little, S.F.; Andrews, G.P.

    2011-01-01

    Although Yersinia pestis is classified as a "high-virulence" pathogen, some host species are variably susceptible to disease. Coyotes (Canis latrans) exhibit mild, if any, symptoms during infection, but antibody production occurs postinfection. This immune response has been reported to be against the F1 capsule, although little subsequent characterization has been conducted. To further define the nature of coyote humoral immunity to plague, qualitative serology was conducted to assess the antiplague antibody repertoire. Humoral responses to six plasmid-encoded Y. pestis virulence factors were first examined. Of 20 individual immune coyotes, 90% were reactive to at least one other antigen in the panel other than F1. The frequency of reactivity to low calcium response plasmid (pLcr)-encoded Yersinia protein kinase A (YpkA) and Yersinia outer protein D (YopD) was significantly greater than that previously observed in a murine model for plague. Additionally, both V antigen and plasminogen activator were reactive with over half of the serum samples tested. Reactivity to F1 was markedly less frequent in coyotes (35%). Twenty previously tested antibody-negative samples were also examined. While the majority were negative across the panel, 15% were positive for 1-3 non-F1 antigens. In vivo-induced antigen technology employed to identify novel chromosomal genes of Y. pestis that are up-regulated during infection resulted in the identification of five proteins, including a flagellar component (FliP) that was uniquely reactive with the coyote serum compared with immune serum from two other host species. Collectively, these data suggest that humoral immunity to pLcr-encoded antigens and the pesticin plasmid (pPst)-encoded Pla antigen may be relevant to plague resistance in coyotes. The serologic profile of Y. pestis chromosomal antigens up-regulated in vivo specific to C. latrans may provide insight into the differences in the pathogen-host responses during Y. pestis infection.

  1. 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.

  2. THE ANTIGEN-SPECIFIC CELL IN VITRO TESTS FOR POST-VACCINATION ANTIPLAGUE IMMUNITY FORMATION

    Directory of Open Access Journals (Sweden)

    A. N. Kulichenko

    2017-01-01

    Full Text Available The possibility of post-vaccination anti-plague immunity evaluation was researched using antigen-stimulated cells tests in vitro and cytometry analysis. The object of study — the blood samples of 17 people immunised by the live plague vaccine (Yersinia pestis EV epicutaneously. Blood taking was carried out before vaccination and after immunisation on 7 and on 21 days, in 3 and in 6 months. Intensity antigen reactivity of lymphocytes was detected by cell tests in vitro, analysing markers of early (CD45+CD3+CD25+ and late (CD45+CD3+HLA-DR+ lymphocyte activation using flow cytometry. The complex of water-soluble Y. pestis antigens and allergen — pestin PP was tested as antigen. The high stimulating potential was defined of the water-soluble antigens Y. pestis complex. It is shown that coefficient of stimulation of relative level T- lymphocytes which express receptors for IL-2 was positive for all observation times after immunisation. The coefficient of stimulation had maximum values at 21 days (56.37% and at 3 (47.41% months. In identifying HLADR-positive lymphocytes before vaccination, the negative coefficient of stimulation was indicated on 7 and 21 days and the positive coefficient of stimulation was indicated at 3 and at 6 months. Analysis of intensity expression of early and late lymphocyte activation markers dynamics showed the possibility and prospect of application of cellular in vitro tests for the laboratory evaluation of specific reactivity of cellular immunity in both the early (7 days and late (6 months periods after vaccination. The results can be the basis for developing a new algorithm for assessment of immunological effectiveness of vaccination people against plague. It is the algorithm based on the identification of lymphocyte activation markers by antigen stimulation in conditions in vitro.

  3. Functional Cloning of Src-like Adapter Protein-2 (SLAP-2), a Novel Inhibitor of Antigen Receptor Signaling

    OpenAIRE

    Holland, Sacha J.; Liao, X.Charlene; Mendenhall, Marcy K.; Zhou, Xiulan; Pardo, Jorge; Chu, Peter; Spencer, Collin; Fu, Alan; Sheng, Ning; Yu, Peiwen; Pali, Erlina; Nagin, Anup; Shen, Mary; Yu, Simon; Chan, Eva

    2001-01-01

    In an effort to identify novel therapeutic targets for autoimmunity and transplant rejection, we developed and performed a large-scale retroviral-based functional screen to select for proteins that inhibit antigen receptor-mediated activation of lymphocytes. In addition to known regulators of antigen receptor signaling, we identified a novel adaptor protein, SLAP-2 which shares 36% sequence similarity with the known Src-like adaptor protein, SLAP. Similar to SLAP, SLAP-2 is predominantly expr...

  4. Antigen-specific CD4 T cells are induced after intravesical BCG-instillation therapy in patients with bladder cancer and show similar cytokine profiles as in active tuberculosis.

    Directory of Open Access Journals (Sweden)

    Julia Elsäßer

    Full Text Available Specific T cell immunity in patients with active tuberculosis is associated with a decrease in multifunctionality. However, it is unknown whether cytokine profiles differ in patients with primary infection and those with prior contact. We therefore used intravesical immunotherapy with attenuated live Bacille Calmette-Guérin (BCG in patients with urothelial carcinoma as a model to characterise the induction of systemic immunity towards purified protein derivate (PPD and to study whether cytokine profiles differ depending on pre-existing immunity