Circulating gluten-specific FOXP3+CD39+ regulatory T cells have impaired suppressive function in patients with celiac disease.

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Cook, Laura; Munier, C Mee Ling; Seddiki, Nabila; van Bockel, David; Ontiveros, Noé; Hardy, Melinda Y; Gillies, Jana K; Levings, Megan K; Reid, Hugh H; Petersen, Jan; Rossjohn, Jamie; Anderson, Robert P; Zaunders, John J; Tye-Din, Jason A; Kelleher, Anthony D

2017-12-01

Celiac disease is a chronic immune-mediated inflammatory disorder of the gut triggered by dietary gluten. Although the effector T-cell response in patients with celiac disease has been well characterized, the role of regulatory T (Treg) cells in the loss of tolerance to gluten remains poorly understood. We sought to define whether patients with celiac disease have a dysfunction or lack of gluten-specific forkhead box protein 3 (FOXP3) + Treg cells. Treated patients with celiac disease underwent oral wheat challenge to stimulate recirculation of gluten-specific T cells. Peripheral blood was collected before and after challenge. To comprehensively measure the gluten-specific CD4 + T-cell response, we paired traditional IFN-γ ELISpot with an assay to detect antigen-specific CD4 + T cells that does not rely on tetramers, antigen-stimulated cytokine production, or proliferation but rather on antigen-induced coexpression of CD25 and OX40 (CD134). Numbers of circulating gluten-specific Treg cells and effector T cells both increased significantly after oral wheat challenge, peaking at day 6. Surprisingly, we found that approximately 80% of the ex vivo circulating gluten-specific CD4 + T cells were FOXP3 + CD39 + Treg cells, which reside within the pool of memory CD4 + CD25 + CD127 low CD45RO + Treg cells. Although we observed normal suppressive function in peripheral polyclonal Treg cells from patients with celiac disease, after a short in vitro expansion, the gluten-specific FOXP3 + CD39 + Treg cells exhibited significantly reduced suppressive function compared with polyclonal Treg cells. This study provides the first estimation of FOXP3 + CD39 + Treg cell frequency within circulating gluten-specific CD4 + T cells after oral gluten challenge of patients with celiac disease. FOXP3 + CD39 + Treg cells comprised a major proportion of all circulating gluten-specific CD4 + T cells but had impaired suppressive function, indicating that Treg cell dysfunction might be a key

Characterization of Antigen-Specific B Cells Using Nominal Antigen-Coated Flow-Beads

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Akl, Ahmed; Lepetit, Maud; Crochette, Romain; Giral, Magali; Lepourry, Julie; Pallier, Annaick; Castagnet, Stéphanie; Dugast, Emilie; Guillot-Gueguen, Cécile; Jacq-Foucher, Marylène; Saulquin, Xavier; Cesbron, Anne; Laplaud, David; Nicot, Arnaud; Brouard, Sophie; Soulillou, Jean-Paul

2013-01-01

In order to characterize the reactivity of B cells against nominal antigens, a method based on the coupling of antigens onto the surface of fluorescent core polystyrene beads was developed. We first demonstrate that murine B cells with a human MOG-specific BCR are able to interact with MOG-coated beads and do not recognize beads coated with human albumin or pp65. B cells purified from human healthy volunteer blood or immunized individuals were tested for their ability to interact with various nominal antigens, including viral, vaccine, self and alloantigens, chosen for their usefulness in studying a variety of pathological processes. A substantial amount of B cells binding self-antigen MOG-coated beads can be detected in normal blood. Furthermore, greater frequencies of B cell against anti-Tetanic Toxin or anti-EBNA1 were observed in primed individuals. This method can reveal increased frequencies of anti-HLA committed B cells in patients with circulating anti-HLA antibodies compared to unsensitized patients and normal individuals. Of interest, those specific CD19 cells were preferentially identified within CD27−IgD+ (i-e naïve) subset. These observations suggest that a broad range of medical situations could benefit from a tool that allows the detection, the quantification and the characterization of antigen-specific blood B cells. PMID:24386360

Cannabinoid Receptor 2 (CB2 Plays a Role in the Generation of Germinal Center and Memory B Cells, but Not in the Production of Antigen-Specific IgG and IgM, in Response to T-dependent Antigens.

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Sreemanti Basu

Full Text Available The cannabinoid receptor 2 (CB2 has been reported to modulate B cell functions including migration, proliferation and isotype class switching. Since these processes are required for the generation of the germinal center (GC and antigen-specific plasma and memory cells following immunization with a T-dependent antigen, CB2 has the capacity to alter the quality and magnitude of T-dependent immune responses. To address this question, we immunized WT and CB2(-/- mice with the T-dependent antigen 4-hydroxy-3-nitrophenylacetyl (NP-chicken-gamma-globulin (CGG and measured GC B cell formation and the generation of antigen-specific B cells and serum immunoglobulin (Ig. While there was a significant reduction in the number of splenic GC B cells in CB2(-/- mice early in the response there was no detectable difference in the number of NP-specific IgM and IgG1 plasma cells. There was also no difference in NP-specific IgM and class switched IgG1 in the serum. In addition, we found no defect in the homing of plasma cells to the bone marrow (BM and affinity maturation, although memory B cell cells in the spleen were reduced in CB2(-/- mice. CB2-deficient mice also generated similar levels of antigen-specific IgM and IgG in the serum as WT following immunization with sheep red blood cells (sRBC. This study demonstrates that although CB2 plays a role in promoting GC and memory B cell formation/maintenance in the spleen, it is dispensable on all immune cell types required for the generation of antigen-specific IgM and IgG in T-dependent immune responses.

Immunodetection of Fasciola gigantica circulating antigen in sera of infected individuals for laboratory diagnosis of human fascioliasis.

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Attallah, Abdelfattah M; Bughdadi, Faisal A; El-Shazly, Atef M; Ismail, Hisham

2013-10-01

Currently, the laboratory diagnosis of human fascioliasis is based on the parasitological examination of parasite eggs in stool specimens and serological detection of specific antibodies in serum samples, which are often unreliable diagnostic approaches. Ideally, a sensitive and specific diagnostic test for Fasciola infection should be based on the detection of circulating Fasciola antigen, which implies active infection. Here, a 27-kDa-molecular-mass antigen was identified in a Fasciola gigantica adult worm antigen preparation, excretory-secretory products, and sera from F. gigantica-infected individuals, and it was not detected in antigenic extracts of other parasites and sera from noninfected individuals. The target antigen was isolated and partially characterized as a protein. Immunoperoxidase staining located the target epitope within teguments and guts of F. gigantica adult worms. The performance characteristics of a newly developed enzyme-linked immunosorbent assay (ELISA) based on F. gigantica circulating antigen detection in serum (FgCA-27 ELISA) were investigated using sera of 120 parasitologically diagnosed F. gigantica-infected individuals and 80 noninfected individuals. The area under the receiving operating characteristic (ROC) curve (AUC) for ELISA was significantly high (AUC = 0.961, P 93%), and a significant correlation (r = 0.715, P fascioliasis.

Persistence of Circulating Hepatitis C Virus Antigens-Specific Immune Complexes in Patients with Resolved HCV Infection.

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Hu, Ke-Qin; Cui, Wei

2018-05-01

Our recent study indicated the possible presence of detectable hepatitis C virus antigens (HCV-Ags) after denaturation of sera with resolved HCV (R-HCV) infection. The present study determined and characterized persistent HCV-Ags-specific immune complexes (ICs) in these patients. Sixty-eight sera with R-HCV and 34 with viremic HCV (V-HCV) infection were tested for free and IC-bound HCV-Ags using HCV-Ags enzyme immunoassay (EIA), the presence of HCV-Ags-specific ICs by immunoprecipitation and Western blot (IP-WB), HCV ICs containing HCV virions using IP and HCV RNA RT-PCR, and correlation of HCV ICs with clinical presentation in these patients. Using HCV-Ags EIA, we found 57.4% of sera with R-HCV infection were tested positive for bound, but not free HCV-Ags. Using pooled or individual anti-HCV E1/E2, cAg, NS3, NS4b, and/or NS5a to precipitate HCV-specific-Ags, we confirmed persistent HCV-Ags ICs specific to various HCV structural and non-structural proteins not only in V-HCV infection, but also in R-HCV infection. Using IP and HCV RNA PCR, we then confirmed the presence of HCV virions within circulating ICs in V-HCV, but not in R-HCV sera. Multivariable analysis indicated significant and independent associations of persistent circulating HCV-Ags-specific ICs with both age and the presence of cirrhosis in patients with R-HCV infection. Various HCV-Ag-specific ICs, but not virions, persist in 57.4% of patients who had spontaneous or treatment-induced HCV clearance for 6 months to 20 years. These findings enriched our knowledge on HCV pathogenesis and support further study on its long-term clinical relevance, such as extrahepatic manifestation, transfusion medicine, and hepatocarcinogenesis.

Induction of IgG memory responses with polyvinylpyrrolidone (PVP) is antigen dose dependent

International Nuclear Information System (INIS)

Lite, H.S.; Braley-Mullen, H.

1981-01-01

Irradiated recipients of spleen cells from mice primed with a very low dose (0.0025 μ/g) of the thymus-independent (TI) antigen polyvinylpyrrolidone (PVP) produced PVP-specific IgG memory responses after secondary challenge with a T-dependent (TD) form of PVP, PVP-HRBC. The IgG memory responses induced by low doses of PVP were similar in magnitude to those induced by the TD antigen PVP-HRBC. The induction of IgG memory by the TI form of antigen was markedly dependent on the dose of PVP used to prime donor mice. Spleen cells from mice primed with an amount of PVP (0.25 μg) that induces an optimal primary IgM response did not produce significant IgG antibody after challenge with PVP-HRBC. The inability of higher doses of PVP to induce IgG memory may be due, at least in part, to the fact that such doses of PVP were found to induce tolerance in PVP-specific B cells and could suppress the induction of memory induced by PVP-HRBC. Low doses of PVP did not interfere with the induction of memory by PVP-HRBC. Expression of IgG memory responses in recipients of PVP-HRBC or low-dose PVP-primed cells was found to be T cell dependent. Moreover, only primed T cells could reconstitute the respnse of recipients of primed B cells, suggesting that the ability of PVP to induce IgG memory may be related to its ability to prime T helper cells. Expression of the IgG memory response in recipient mice also required the use of a TD antigen for secondary challenge, i.e., mice challenged with PVP did not develop IgG

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

International Nuclear Information System (INIS)

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

1980-01-01

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

Immunodetection of Fasciola gigantica Circulating Antigen in Sera of Infected Individuals for Laboratory Diagnosis of Human Fascioliasis

Science.gov (United States)

Attallah, Abdelfattah M.; Bughdadi, Faisal A.; El-Shazly, Atef M.

2013-01-01

Currently, the laboratory diagnosis of human fascioliasis is based on the parasitological examination of parasite eggs in stool specimens and serological detection of specific antibodies in serum samples, which are often unreliable diagnostic approaches. Ideally, a sensitive and specific diagnostic test for Fasciola infection should be based on the detection of circulating Fasciola antigen, which implies active infection. Here, a 27-kDa-molecular-mass antigen was identified in a Fasciola gigantica adult worm antigen preparation, excretory-secretory products, and sera from F. gigantica-infected individuals, and it was not detected in antigenic extracts of other parasites and sera from noninfected individuals. The target antigen was isolated and partially characterized as a protein. Immunoperoxidase staining located the target epitope within teguments and guts of F. gigantica adult worms. The performance characteristics of a newly developed enzyme-linked immunosorbent assay (ELISA) based on F. gigantica circulating antigen detection in serum (FgCA-27 ELISA) were investigated using sera of 120 parasitologically diagnosed F. gigantica-infected individuals and 80 noninfected individuals. The area under the receiving operating characteristic (ROC) curve (AUC) for ELISA was significantly high (AUC = 0.961, P 93%), and a significant correlation (r = 0.715, P fascioliasis. PMID:23945158

Memory control by the B cell antigen receptor.

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Engels, Niklas; Wienands, Jürgen

2018-05-01

The generation of memory B cells (MBCs) that have undergone immunoglobulin class switching from IgM, which dominates primary antibody responses, to other immunoglobulin isoforms is a hallmark of immune memory. Hence, humoral immunological memory is characterized by the presence of serum immunoglobulins of IgG subtypes known as the γ-globulin fraction of blood plasma proteins. These antibodies reflect the antigen experience of B lymphocytes and their repeated triggering. In fact, efficient protection against a previously encountered pathogen is critically linked to the production of pathogen-specific IgG molecules even in those cases where the primary immune response required cellular immunity, for example, T cell-mediated clearance of intracellular pathogens such as viruses. Besides IgG, also IgA and IgE can provide humoral immunity depending on the microbe's nature and infection route. The molecular mechanisms underlying the preponderance of switched immunoglobulin isotypes during memory antibody responses are a matter of active and controversial debate. Here, we summarize the phenotypic characteristics of distinct MBC subpopulations and discuss the decisive roles of different B cell antigen receptor isotypes for the functional traits of class-switched B cell populations. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

T Lymphocyte-Endothelial Interactions: Emerging Understanding of Trafficking and Antigen-Specific Immunity

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Christopher Vincent Carman

2015-11-01

Full Text Available Antigen-specific immunity requires regulated trafficking of T cells in and out of diverse tissues in order to orchestrate lymphocyte development, immune surveillance, responses and memory. The endothelium serves as a unique barrier, as well as a sentinel, between the blood and the tissues and as such it plays an essential locally tuned role in regulating T cell migration and information exchange. While it is well established that chemoattractants and adhesion molecules are major determinants of T cell trafficking, emerging studies have now enumerated a large number of molecular players as well as a range of discrete cellular remodeling activities (e.g. transmigratory cups and invadosome-like protrusions, IPLs that participate in directed migration and pathfinding by T cells. In addition to providing trafficking cues, intimate cell-cell interaction between lymphocytes and endothelial cells provide instruction to T cells that influence their activation and differentiation states. Perhaps the most intriguing and underappreciated of these ‘sentinel’ roles is the ability of the endothelium to act as a non-hematopoietic ‘semi-professional’ antigen-presenting cell. Close contacts between circulating T cells and antigen-presenting endothelium may play unique non-redundant roles in shaping adaptive immune responses within the periphery. A better understanding of the mechanisms directing T cell trafficking and the antigen-presenting role of the endothelium may not only increase our knowledge of the adaptive immune response but also empower the utility of emerging immunomodulatory therapeutics.

Effects of immunosuppression on circulating adeno-associated virus capsid-specific T cells in humans.

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Parzych, Elizabeth M; Li, Hua; Yin, Xiangfan; Liu, Qin; Wu, Te-Lang; Podsakoff, Gregory M; High, Katherine A; Levine, Matthew H; Ertl, Hildegund C J

2013-04-01

In humans adeno-associated virus (AAV)-mediated gene transfer is followed by expansion of AAV capsid-specific T cells, evidence of cell damage, and loss of transgene product expression, implicating immunological rejection of vector-transduced cells, which may be prevented by immunosuppressive drugs. We undertook this study to assess the effect of immunosuppression (IS) used for organ transplantation on immune responses to AAV capsid antigens. Recipients of liver or kidney transplants were tested before and 4 weeks after induction of IS in comparison with matched samples from healthy human adults and an additional cohort with comorbid conditions similar to those of the transplant patients. Our data show that transplant patients and comorbid control subjects have markedly higher frequencies of circulating AAV capsid-specific T cells compared with healthy adults. On average, IS resulted in a reduction of AAV-specific CD4⁺ T cells, whereas numbers of circulating CD8⁺ effector and central memory T cells tended to increase. Independent of the type of transplant or the IS regimens, the trend of AAV capsid-specific T cell responses after drug treatment varied; in some patients responses were unaffected whereas others showed decreases or even pronounced increases, casting doubt on the usefulness of prophylactic IS for AAV vector recipients.

Generation of Recombinant Monoclonal Antibodies from Immunised Mice and Rabbits via Flow Cytometry and Sorting of Antigen-Specific IgG+ Memory B Cells.

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Dale O Starkie

Full Text Available Single B cell screening strategies, which avoid both hybridoma fusion and combinatorial display, have emerged as important technologies for efficiently sampling the natural antibody repertoire of immunized animals and humans. Having access to a range of methods to interrogate different B cell subsets provides an attractive option to ensure large and diverse panels of high quality antibody are produced. The generation of multiple antibodies and having the ability to find rare B cell clones producing IgG with unique and desirable characteristics facilitates the identification of fit-for-purpose molecules that can be developed into therapeutic agents or research reagents. Here, we describe a multi-parameter flow cytometry single-cell sorting technique for the generation of antigen-specific recombinant monoclonal antibodies from single IgG+ memory B cells. Both mouse splenocytes and rabbit PBMC from immunised animals were used as a source of B cells. Reagents staining both B cells and other unwanted cell types enabled efficient identification of class-switched IgG+ memory B cells. Concurrent staining with antigen labelled separately with two spectrally-distinct fluorophores enabled antigen-specific B cells to be identified, i.e. those which bind to both antigen conjugates (double-positive. These cells were then typically sorted at one cell per well using FACS directly into a 96-well plate containing reverse transcriptase reaction mix. Following production of cDNA, PCR was performed to amplify cognate heavy and light chain variable region genes and generate transcriptionally-active PCR (TAP fragments. These linear expression cassettes were then used directly in a mammalian cell transfection to generate recombinant antibody for further testing. We were able to successfully generate antigen-specific recombinant antibodies from both the rabbit and mouse IgG+ memory B cell subset within one week. This included the generation of an anti-TNFR2 blocking

Circulating rotavirus-specific T cells have a poor functional profile

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Parra, Miguel; Herrera, Daniel; Jácome, María Fernanda; Mesa, Martha C.; Rodríguez, Luz-Stella; Guzmán, Carolina; Angel, Juana; Franco, Manuel A.

2014-01-01

Frequencies of circulating T cells producing IFN-γ, TNF-α, and IL-2, and percentages of T cells proliferating after stimulation with rotavirus (RV), tetanus toxoid, and influenza were evaluated in PBMC derived from healthy adults and children. In addition, the potential anergic state of RV-specific T cells was analyzed by stimulation of PBMC with RV antigen in the presence of three anergy inhibitors (rIL-2, rIL-12, or DGKα-i). The quality and magnitude of RV-T cell responses were significantly lower than those of tetanus toxoid and influenza antigens. RV-CD4 T cell response was enriched in monofunctional IFN-γ + cells, while influenza-CD4 and tetanus toxoid-CD4 T cell responses were enriched in multifunctional T cells. Moreover, rIL-2 – unlike rIL-12 or DGKα-i – increased the frequencies of RV-CD4 TNF-α + , CD4 IFN-γ + , and CD8 IFN-γ + cells. Thus, circulating RV-T cells seem to have a relatively poor functional profile that may be partially reversed in vitro by the addition of rIL-2. - Highlights: • The quality and magnitude of circulating RV-T cell responses are relatively poor. • Circulating RV-CD4 T cells are enriched in monofunctional IFN-γ+ cells. • Treatment with rIL-2 increased the frequencies of cytokine secreting RV-T cells

A High Frequency of HIV-Specific Circulating Follicular Helper T Cells Is Associated with Preserved Memory B Cell Responses in HIV Controllers.

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Claireaux, M; Galperin, M; Benati, D; Nouël, A; Mukhopadhyay, M; Klingler, J; de Truchis, P; Zucman, D; Hendou, S; Boufassa, F; Moog, C; Lambotte, O; Chakrabarti, L A

2018-05-08

Follicular helper T cells (Tfh) play an essential role in the affinity maturation of the antibody response by providing help to B cells. To determine whether this CD4 + T cell subset may contribute to the spontaneous control of HIV infection, we analyzed the phenotype and function of circulating Tfh (cTfh) in patients from the ANRS CO21 CODEX cohort who naturally controlled HIV-1 replication to undetectable levels and compared them to treated patients with similarly low viral loads. HIV-specific cTfh (Tet + ), detected by Gag-major histocompatibility complex class II (MHC-II) tetramer labeling in the CD45RA - CXCR5 + CD4 + T cell population, proved more frequent in the controller group ( P = 0.002). The frequency of PD-1 expression in Tet + cTfh was increased in both groups (median, >75%) compared to total cTfh (<30%), but the intensity of PD-1 expression per cell remained higher in the treated patient group ( P = 0.02), pointing to the persistence of abnormal immune activation in treated patients. The function of cTfh, analyzed by the capacity to promote IgG secretion in cocultures with autologous memory B cells, did not show major differences between groups in terms of total IgG production but proved significantly more efficient in the controller group when measuring HIV-specific IgG production. The frequency of Tet + cTfh correlated with HIV-specific IgG production ( R = 0.71 for Gag-specific and R = 0.79 for Env-specific IgG, respectively). Taken together, our findings indicate that key cTfh-B cell interactions are preserved in controlled HIV infection, resulting in potent memory B cell responses that may play an underappreciated role in HIV control. IMPORTANCE The rare patients who spontaneously control HIV replication in the absence of therapy provide a unique model to identify determinants of an effective anti-HIV immune response. HIV controllers show signs of particularly efficient antiviral T cell responses, while their humoral response was until recently

Secondary immunization generates clonally related antigen-specific plasma cells and memory B cells.

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Frölich, Daniela; Giesecke, Claudia; Mei, Henrik E; Reiter, Karin; Daridon, Capucine; Lipsky, Peter E; Dörner, Thomas

2010-09-01

Rechallenge with T cell-dependent Ags induces memory B cells to re-enter germinal centers (GCs) and undergo further expansion and differentiation into plasma cells (PCs) and secondary memory B cells. It is currently not known whether the expanded population of memory B cells and PCs generated in secondary GCs are clonally related, nor has the extent of proliferation and somatic hypermutation of their precursors been delineated. In this study, after secondary tetanus toxoid (TT) immunization, TT-specific PCs increased 17- to 80-fold on days 6-7, whereas TT-specific memory B cells peaked (delayed) on day 14 with a 2- to 22-fold increase. Molecular analyses of V(H)DJ(H) rearrangements of individual cells revealed no major differences of gene usage and CDR3 length between TT-specific PCs and memory B cells, and both contained extensive evidence of somatic hypermutation with a pattern consistent with GC reactions. This analysis identified clonally related TT-specific memory B cells and PCs. Within clusters of clonally related cells, sequences shared a number of mutations but also could contain additional base pair changes. The data indicate that although following secondary immunization PCs can derive from memory B cells without further somatic hypermutation, in some circumstances, likely within GC reactions, asymmetric mutation can occur. These results suggest that after the fate decision to differentiate into secondary memory B cells or PCs, some committed precursors continue to proliferate and mutate their V(H) genes.

Circulating rotavirus-specific T cells have a poor functional profile

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Parra, Miguel; Herrera, Daniel [Instituto de Genética Humana, Facultad de Medicina, Pontificia Universidad Javeriana, Pontificia Universidad Javeriana, Carrera 7 # 40-62, Bogotá (Colombia); Jácome, María Fernanda; Mesa, Martha C. [Departamento de Microbiología, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá (Colombia); Rodríguez, Luz-Stella [Instituto de Genética Humana, Facultad de Medicina, Pontificia Universidad Javeriana, Pontificia Universidad Javeriana, Carrera 7 # 40-62, Bogotá (Colombia); Guzmán, Carolina [Departamento de Pediatría, Hospital Universitario San Ignacio, Facultad de Medicina, Pontificia Universidad Javeriana, Bogotá (Colombia); Angel, Juana; Franco, Manuel A. [Instituto de Genética Humana, Facultad de Medicina, Pontificia Universidad Javeriana, Pontificia Universidad Javeriana, Carrera 7 # 40-62, Bogotá (Colombia)

2014-11-15

Frequencies of circulating T cells producing IFN-γ, TNF-α, and IL-2, and percentages of T cells proliferating after stimulation with rotavirus (RV), tetanus toxoid, and influenza were evaluated in PBMC derived from healthy adults and children. In addition, the potential anergic state of RV-specific T cells was analyzed by stimulation of PBMC with RV antigen in the presence of three anergy inhibitors (rIL-2, rIL-12, or DGKα-i). The quality and magnitude of RV-T cell responses were significantly lower than those of tetanus toxoid and influenza antigens. RV-CD4 T cell response was enriched in monofunctional IFN-γ{sup +} cells, while influenza-CD4 and tetanus toxoid-CD4 T cell responses were enriched in multifunctional T cells. Moreover, rIL-2 – unlike rIL-12 or DGKα-i – increased the frequencies of RV-CD4 TNF-α{sup +}, CD4 IFN-γ{sup +}, and CD8 IFN-γ{sup +} cells. Thus, circulating RV-T cells seem to have a relatively poor functional profile that may be partially reversed in vitro by the addition of rIL-2. - Highlights: • The quality and magnitude of circulating RV-T cell responses are relatively poor. • Circulating RV-CD4 T cells are enriched in monofunctional IFN-γ+ cells. • Treatment with rIL-2 increased the frequencies of cytokine secreting RV-T cells.

Immunization Elicits Antigen-Specific Antibody Sequestration in Dorsal Root Ganglia Sensory Neurons

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Gunasekaran, Manojkumar; Chatterjee, Prodyot K.; Shih, Andrew; Imperato, Gavin H.; Addorisio, Meghan; Kumar, Gopal; Lee, Annette; Graf, John F.; Meyer, Dan; Marino, Michael; Puleo, Christopher; Ashe, Jeffrey; Cox, Maureen A.; Mak, Tak W.; Bouton, Chad; Sherry, Barbara; Diamond, Betty; Andersson, Ulf; Coleman, Thomas R.; Metz, Christine N.; Tracey, Kevin J.; Chavan, Sangeeta S.

2018-01-01

The immune and nervous systems are two major organ systems responsible for host defense and memory. Both systems achieve memory and learning that can be retained, retrieved, and utilized for decades. Here, we report the surprising discovery that peripheral sensory neurons of the dorsal root ganglia (DRGs) of immunized mice contain antigen-specific antibodies. Using a combination of rigorous molecular genetic analyses, transgenic mice, and adoptive transfer experiments, we demonstrate that DRGs do not synthesize these antigen-specific antibodies, but rather sequester primarily IgG1 subtype antibodies. As revealed by RNA-seq and targeted quantitative PCR (qPCR), dorsal root ganglion (DRG) sensory neurons harvested from either naïve or immunized mice lack enzymes (i.e., RAG1, RAG2, AID, or UNG) required for generating antibody diversity and, therefore, cannot make antibodies. Additionally, transgenic mice that express a reporter fluorescent protein under the control of Igγ1 constant region fail to express Ighg1 transcripts in DRG sensory neurons. Furthermore, neural sequestration of antibodies occurs in mice rendered deficient in neuronal Rag2, but antibody sequestration is not observed in DRG sensory neurons isolated from mice that lack mature B cells [e.g., Rag1 knock out (KO) or μMT mice]. Finally, adoptive transfer of Rag1-deficient bone marrow (BM) into wild-type (WT) mice or WT BM into Rag1 KO mice revealed that antibody sequestration was observed in DRG sensory neurons of chimeric mice with WT BM but not with Rag1-deficient BM. Together, these results indicate that DRG sensory neurons sequester and retain antigen-specific antibodies released by antibody-secreting plasma cells. Coupling this work with previous studies implicating DRG sensory neurons in regulating antigen trafficking during immunization raises the interesting possibility that the nervous system collaborates with the immune system to regulate antigen-mediated responses. PMID:29755449

Immunization Elicits Antigen-Specific Antibody Sequestration in Dorsal Root Ganglia Sensory Neurons

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Manojkumar Gunasekaran

2018-04-01

Full Text Available The immune and nervous systems are two major organ systems responsible for host defense and memory. Both systems achieve memory and learning that can be retained, retrieved, and utilized for decades. Here, we report the surprising discovery that peripheral sensory neurons of the dorsal root ganglia (DRGs of immunized mice contain antigen-specific antibodies. Using a combination of rigorous molecular genetic analyses, transgenic mice, and adoptive transfer experiments, we demonstrate that DRGs do not synthesize these antigen-specific antibodies, but rather sequester primarily IgG1 subtype antibodies. As revealed by RNA-seq and targeted quantitative PCR (qPCR, dorsal root ganglion (DRG sensory neurons harvested from either naïve or immunized mice lack enzymes (i.e., RAG1, RAG2, AID, or UNG required for generating antibody diversity and, therefore, cannot make antibodies. Additionally, transgenic mice that express a reporter fluorescent protein under the control of Igγ1 constant region fail to express Ighg1 transcripts in DRG sensory neurons. Furthermore, neural sequestration of antibodies occurs in mice rendered deficient in neuronal Rag2, but antibody sequestration is not observed in DRG sensory neurons isolated from mice that lack mature B cells [e.g., Rag1 knock out (KO or μMT mice]. Finally, adoptive transfer of Rag1-deficient bone marrow (BM into wild-type (WT mice or WT BM into Rag1 KO mice revealed that antibody sequestration was observed in DRG sensory neurons of chimeric mice with WT BM but not with Rag1-deficient BM. Together, these results indicate that DRG sensory neurons sequester and retain antigen-specific antibodies released by antibody-secreting plasma cells. Coupling this work with previous studies implicating DRG sensory neurons in regulating antigen trafficking during immunization raises the interesting possibility that the nervous system collaborates with the immune system to regulate antigen-mediated responses.

Induction of Robust B Cell Responses after Influenza mRNA Vaccination Is Accompanied by Circulating Hemagglutinin-Specific ICOS+ PD-1+ CXCR3+ T Follicular Helper Cells

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Gustaf Lindgren

2017-11-01

Full Text Available Modified mRNA vaccines have developed into an effective and well-tolerated vaccine platform that offers scalable and precise antigen production. Nevertheless, the immunological events leading to strong antibody responses elicited by mRNA vaccines are largely unknown. In this study, we demonstrate that protective levels of antibodies to hemagglutinin were induced after two immunizations of modified non-replicating mRNA encoding influenza H10 encapsulated in lipid nanoparticles (LNP in non-human primates. While both intradermal (ID and intramuscular (IM administration induced protective titers, ID delivery generated this response more rapidly. Circulating H10-specific memory B cells expanded after each immunization, along with a transient appearance of plasmablasts. The memory B cell pool waned over time but remained detectable throughout the 25-week study. Following prime immunization, H10-specific plasma cells were found in the bone marrow and persisted over time. Germinal centers were formed in vaccine-draining lymph nodes along with an increase in circulating H10-specific ICOS+ PD-1+ CXCR3+ T follicular helper cells, a population shown to correlate with high avidity antibody responses after seasonal influenza vaccination in humans. Collectively, this study demonstrates that mRNA/LNP vaccines potently induce an immunological repertoire associated with the generation of high magnitude and quality antibodies.

Circulating rotavirus-specific T cells have a poor functional profile.

Science.gov (United States)

Parra, Miguel; Herrera, Daniel; Jácome, María Fernanda; Mesa, Martha C; Rodríguez, Luz-Stella; Guzmán, Carolina; Angel, Juana; Franco, Manuel A

2014-11-01

Frequencies of circulating T cells producing IFN-γ, TNF-α, and IL-2, and percentages of T cells proliferating after stimulation with rotavirus (RV), tetanus toxoid, and influenza were evaluated in PBMC derived from healthy adults and children. In addition, the potential anergic state of RV-specific T cells was analyzed by stimulation of PBMC with RV antigen in the presence of three anergy inhibitors (rIL-2, rIL-12, or DGKα-i). The quality and magnitude of RV-T cell responses were significantly lower than those of tetanus toxoid and influenza antigens. RV-CD4 T cell response was enriched in monofunctional IFN-γ(+) cells, while influenza-CD4 and tetanus toxoid-CD4 T cell responses were enriched in multifunctional T cells. Moreover, rIL-2--unlike rIL-12 or DGKα-i--increased the frequencies of RV-CD4 TNF-α(+), CD4 IFN-γ(+), and CD8 IFN-γ(+) cells. Thus, circulating RV-T cells seem to have a relatively poor functional profile that may be partially reversed in vitro by the addition of rIL-2. Copyright © 2014 Elsevier Inc. All rights reserved.

CD4+ virtual memory: Antigen-inexperienced T cells reside in the naïve, regulatory, and memory T cell compartments at similar frequencies, implications for autoimmunity.

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Marusina, Alina I; Ono, Yoko; Merleev, Alexander A; Shimoda, Michiko; Ogawa, Hiromi; Wang, Elizabeth A; Kondo, Kayo; Olney, Laura; Luxardi, Guillaume; Miyamura, Yoshinori; Yilma, Tilahun D; Villalobos, Itzel Bustos; Bergstrom, Jennifer W; Kronenberg, Daniel G; Soulika, Athena M; Adamopoulos, Iannis E; Maverakis, Emanual

2017-02-01

It is widely accepted that central and effector memory CD4 + T cells originate from naïve T cells after they have encountered their cognate antigen in the setting of appropriate co-stimulation. However, if this were true the diversity of T cell receptor (TCR) sequences within the naïve T cell compartment should be far greater than that of the memory T cell compartment, which is not supported by TCR sequencing data. Here we demonstrate that aged mice with far fewer naïve T cells, respond to the model antigen, hen eggwhite lysozyme (HEL), by utilizing the same TCR sequence as their younger counterparts. CD4 + T cell repertoire analysis of highly purified T cell populations from naive animals revealed that the HEL-specific clones displayed effector and central "memory" cell surface phenotypes even prior to having encountered their cognate antigen. Furthermore, HEL-inexperienced CD4 + T cells were found to reside within the naïve, regulatory, central memory, and effector memory T cell populations at similar frequencies and the majority of the CD4 + T cells within the regulatory and memory populations were unexpanded. These findings support a new paradigm for CD4 + T cell maturation in which a specific clone can undergo a differentiation process to exhibit a "memory" or regulatory phenotype without having undergone a clonal expansion event. It also demonstrates that a foreign-specific T cell is just as likely to reside within the regulatory T cell compartment as it would the naïve compartment, arguing against the specificity of the regulatory T cell compartment being skewed towards self-reactive T cell clones. Finally, we demonstrate that the same set of foreign and autoreactive CD4 + T cell clones are repetitively generated throughout adulthood. The latter observation argues against T cell-depleting strategies or autologous stem cell transplantation as therapies for autoimmunity-as the immune system has the ability to regenerate pathogenic clones. Published by

Predictive value of different prostate-specific antigen-based markers in men with baseline total prostate-specific antigen <2.0 ng/mL.

Science.gov (United States)

Fujizuka, Yuji; Ito, Kazuto; Oki, Ryo; Suzuki, Rie; Sekine, Yoshitaka; Koike, Hidekazu; Matsui, Hiroshi; Shibata, Yasuhiro; Suzuki, Kazuhiro

2017-08-01

To investigate the predictive value of various molecular forms of prostate-specific antigen in men with baseline prostate-specific antigen baseline prostate-specific antigen level baseline prostate-specific antigen- and age-adjusted men who did not develop prostate cancer. Serum prostate-specific antigen, free prostate-specific antigen, and [-2] proenzyme prostate-specific antigen were measured at baseline and last screening visit. The predictive impact of baseline prostate-specific antigen- and [-2] proenzyme prostate-specific antigen-related indices on developing prostate cancer was investigated. The predictive impact of those indices at last screening visit and velocities from baseline to final screening on tumor aggressiveness were also investigated. The baseline free to total prostate-specific antigen ratio was a significant predictor of prostate cancer development. The odds ratio was 6.08 in the lowest quintile baseline free to total prostate-specific antigen ratio subgroup. No serum indices at diagnosis were associated with tumor aggressiveness. The Prostate Health Index velocity and [-2] proenzyme prostate-specific antigen/free prostate-specific antigen velocity significantly increased in patients with higher risk D'Amico risk groups and higher Gleason scores. Free to total prostate-specific antigen ratio in men with low baseline prostate-specific antigen levels seems to predict the risk of developing prostate cancer, and it could be useful for a more effective individualized screening system. Longitudinal changes in [-2] proenzyme prostate-specific antigen-related indices seem to correlate with tumor aggressiveness, and they could be used as prognostic tool before treatment and during active surveillance. © 2017 The Japanese Urological Association.

Sensitivity and specificity of three Onchocerca volvulus cloned antigens in diagnosis of onchocerciasis

International Nuclear Information System (INIS)

Atti, Miska Elyemen; TR, Unnasch; Mukhtar, M.M.

1999-01-01

Onchcerciasis is endemic in three geographical regions in Sudan, and presented with variable clinical reactions. The current diagnosis of onchocerciasis is based on detection of live microflaraie in skin snips in addition to clinical signs and history of living in endemic regions. Different serological diagnostic trials using crude soluble antigens of O. volvulus have shown variable degrees of cross reaction with other nematodes co-endemic in the same area. We have studied the sensitivity and specificity of RAL-2, calreticulin and PDI O. volvulus cloned antigens using the ELISA techniques. Eighty serum samples of Onchocerciasis patients, 20 non endemic normal controls and 42 samples of patients of other endemic deseas including Leishmanoasis, malaria, tuberculosis and shestosomiasis were tested RAL-2 gave the best Ig G response, with 83.75% sensitivity and 91. 66% specificity. PDI sensitivity was 20% and specificity 91.66%, while calreticulum showed sensitivity of 37.5% and specificity of 73.30%. IgG3 subclasses was not significantly different from controls while IgG4 was significantly higher in patients. The sensitivity of RAL-2 for IgG4 was 90% with a specificity of 100%. For PDI sensitivity was 25% and 100% specificity while calreticulin resulted in sensitivity of 75% and specificity of 100%. Low levels of circulating IgE to RAL-2 antigen were detected. For all antigens there was significant correlation with gender, age, microflarial load or presence of nodules. (Author)

Prostate-specific antigen velocity is not better than total prostate-specific antigen in predicting prostate biopsy diagnosis.

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Gorday, William; Sadrzadeh, Hossein; de Koning, Lawrence; Naugler, Christopher T

2015-12-01

1.) Identify whether prostate-specific antigen velocity improves the ability to predict prostate biopsy diagnosis. 2.) Test whether there is an increase in the predictive capability of models when Gleason 7 prostate cancers are separated into a 3+4 and a 4+3 group. Calgary Laboratory Services' Clinical Laboratory Information System was searched for prostate biopsies reported between January 1, 2009 and December 31, 2013. Total prostate-specific antigen tests were recorded for each patient from January 1, 2007 to the most recent test before their recorded prostate biopsy. The data set was divided into the following three groups for comparison; benign, all prostate cancer and Gleason 7-10. The Gleason grade 7-10 group was further divided into 4+3 and 3+4 Gleason 7 prostate cancers. Prostate-specific antigen velocity was calculated using four different methods found in the literature. Receiver operator curves were used to assess operational characteristics of the tests. 4622 men between the ages of 40-89 with a prostate biopsy were included for analysis. Combining prostate-specific antigen velocity with total prostate-specific antigen (AUC=0.570-0.712) resulted in small non-statistically significant changes to the area under the curve compared to the area under the curve of total prostate-specific antigen alone (AUC=0.572-0.699). There were marked increases in the area under curves when 3+4 and 4+3 Gleason 7 cancers were separated. Prostate-specific antigen velocity does not add predictive value for prostate biopsy diagnosis. The clinical significance of the prostate specific antigen test can be improved by separating Gleason 7 prostate cancers into a 3+4 and 4+3 group. Copyright © 2015 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Selective Memory to Apoptotic Cell-Derived Self-Antigens with Implications for Systemic Lupus Erythematosus Development.

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Duhlin, Amanda; Chen, Yunying; Wermeling, Fredrik; Sedimbi, Saikiran K; Lindh, Emma; Shinde, Rahul; Halaby, Marie Jo; Kaiser, Ylva; Winqvist, Ola; McGaha, Tracy L; Karlsson, Mikael C I

2016-10-01

Autoimmune diseases are characterized by pathogenic immune responses to self-antigens. In systemic lupus erythematosus (SLE), many self-antigens are found in apoptotic cells (ACs), and defects in removal of ACs from the body are linked to a risk for developing SLE. This includes pathological memory that gives rise to disease flares. In this study, we investigated how memory to AC-derived self-antigens develops and the contribution of self-memory to the development of lupus-related pathology. Multiple injections of ACs without adjuvant into wild-type mice induce a transient primary autoimmune response without apparent anti-nuclear Ab reactivity or kidney pathology. Interestingly, as the transient Ab response reached baseline, a single boost injection fully recalled the immune response to ACs, and this memory response was furthermore transferable into naive mice. Additionally, the memory response contains elements of pathogenicity, accompanied by selective memory to selective Ags. Thus, we provide evidence for a selective self-memory that underlies progression of the response to self-antigens with implications for SLE development therapy. Copyright © 2016 by The American Association of Immunologists, Inc.

Retention of Ag-specific memory CD4+ T cells in the draining lymph node indicates lymphoid tissue resident memory populations.

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Marriott, Clare L; Dutton, Emma E; Tomura, Michio; Withers, David R

2017-05-01

Several different memory T-cell populations have now been described based upon surface receptor expression and migratory capabilities. Here we have assessed murine endogenous memory CD4 + T cells generated within a draining lymph node and their subsequent migration to other secondary lymphoid tissues. Having established a model response targeting a specific peripheral lymph node, we temporally labelled all the cells within draining lymph node using photoconversion. Tracking of photoconverted and non-photoconverted Ag-specific CD4 + T cells revealed the rapid establishment of a circulating memory population in all lymph nodes within days of immunisation. Strikingly, a resident memory CD4 + T cell population became established in the draining lymph node and persisted for several months in the absence of detectable migration to other lymphoid tissue. These cells most closely resembled effector memory T cells, usually associated with circulation through non-lymphoid tissue, but here, these cells were retained in the draining lymph node. These data indicate that lymphoid tissue resident memory CD4 + T-cell populations are generated in peripheral lymph nodes following immunisation. © 2017 The Authors. European Journal of Immunology published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Long-term Maintenance of CD4 T Cell Memory Responses to Malaria Antigens in Malian Children Coinfected with Schistosoma haematobium

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Kirsten E. Lyke

2018-02-01

Full Text Available Polyparasitism is common in the developing world. We have previously demonstrated that schistosomiasis-positive (SP Malian children, aged 4–8 years, are protected from malaria compared to matched schistosomiasis-negative (SN children. The effect of concomitant schistosomiasis upon acquisition of T cell memory is unknown. We examined antigen-specific T cell frequencies in 48 Malian children aged 4–14 to a pool of malaria blood stage antigens, and a pool of schistosomal antigens, at a time point during a malaria episode and at a convalescent time point ~6 months later, following cessation of malaria transmission. CD4+ T cell-derived memory responses, defined as one or more significant cytokine (IFN-γ, TNF-α, IL-2, and/or IL-17A responses, was measured to schistoma antigens in 18/23 SP children at one or both time points, compared to 4/23 SN children (P < 0.0001. At the time of malaria infection, 12/24 SN children and 15/23 SP children (P = 0.29 stimulated with malaria antigens demonstrated memory recall as defined by CD4-derived cytokine production. This compares to 7/23 SN children and 16/23 SP children (P = 0.009 at the convalescent timepoint. 46.2% of cytokine-producing CD4+ T cells expressed a single cytokine after stimulation with malaria antigen during the malaria episode. This fell to 40.9% at follow-up with a compensatory rise of multifunctional cytokine secretion over time, a phenomenon consistent with memory maturation. The majority (53.2–59.5% of responses derived from CD45RA−CD62L− effector memory T cells with little variation in the phenotype depending upon the time point or the study cohort. We conclude that detectable T cell memory responses can be measured against both malaria and schistosoma antigens and that the presence of Schistosoma haematobium may be associated with long-term maintenance of T memory to malaria.

Reduced Serum IgG Responses to Pneumococcal Antigens in Otitis-Prone Children May Be Due to Poor Memory B-Cell Generation

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Sharma, Sharad K.; Casey, Janet R.

2012-01-01

A low level of serum antibody to antigens expressed by Streptococcus pneumoniae has been proposed to explain the susceptibility of children to recurrent episodes of acute otitis media (hereafter, “otitis-prone children”). By use of enzyme-linked immunospot assays, the percentages of memory B cells to pneumococcal protein antigens PhtD, LytB, PcpA, PhtE, and Ply were compared between otitis-prone and non–otitis-prone children at the time of acute otitis media or nasopharyngeal colonization with S. pneumoniae. We found significantly lower percentages of memory B cells to 3 pneumococcal protein antigens (PhtD, PhtE, and Ply) and reduced antigen-specific immunoglobulin G concentrations in otitis-prone children, compared with non–otitis-prone children. PMID:22383675

Evaluation of Antigen-Conjugated Fluorescent Beads to Identify Antigen-Specific B Cells

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Isabel Correa

2018-03-01

Full Text Available Selection of single antigen-specific B cells to identify their expressed antibodies is of considerable interest for evaluating human immune responses. Here, we present a method to identify single antibody-expressing cells using antigen-conjugated fluorescent beads. To establish this, we selected Folate Receptor alpha (FRα as a model antigen and a mouse B cell line, expressing both the soluble and the membrane-bound forms of a human/mouse chimeric antibody (MOv18 IgG1 specific for FRα, as test antibody-expressing cells. Beads were conjugated to FRα using streptavidin/avidin-biotin bridges and used to select single cells expressing the membrane-bound form of anti-FRα. Bead-bound cells were single cell-sorted and processed for single cell RNA retrotranscription and PCR to isolate antibody heavy and light chain variable regions. Variable regions were then cloned and expressed as human IgG1/k antibodies. Like the original clone, engineered antibodies from single cells recognized native FRα. To evaluate whether antigen-coated beads could identify specific antibody-expressing cells in mixed immune cell populations, human peripheral blood mononuclear cells (PBMCs were spiked with test antibody-expressing cells. Antigen-specific cells could comprise up to 75% of cells selected with antigen-conjugated beads when the frequency of the antigen-positive cells was 1:100 or higher. In PBMC pools, beads conjugated to recombinant antigens FRα and HER2 bound antigen-specific anti-FRα MOv18 and anti-HER2 Trastuzumab antibody-expressing cells, respectively. From melanoma patient-derived B cells selected with melanoma cell line-derived protein-coated fluorescent beads, we generated a monoclonal antibody that recognized melanoma antigen-coated beads. This approach may be further developed to facilitate analysis of B cells and their antibody profiles at the single cell level and to help unravel humoral immune repertoires.

Evaluation of Antigen-Conjugated Fluorescent Beads to Identify Antigen-Specific B Cells.

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Correa, Isabel; Ilieva, Kristina M; Crescioli, Silvia; Lombardi, Sara; Figini, Mariangela; Cheung, Anthony; Spicer, James F; Tutt, Andrew N J; Nestle, Frank O; Karagiannis, Panagiotis; Lacy, Katie E; Karagiannis, Sophia N

2018-01-01

Selection of single antigen-specific B cells to identify their expressed antibodies is of considerable interest for evaluating human immune responses. Here, we present a method to identify single antibody-expressing cells using antigen-conjugated fluorescent beads. To establish this, we selected Folate Receptor alpha (FRα) as a model antigen and a mouse B cell line, expressing both the soluble and the membrane-bound forms of a human/mouse chimeric antibody (MOv18 IgG1) specific for FRα, as test antibody-expressing cells. Beads were conjugated to FRα using streptavidin/avidin-biotin bridges and used to select single cells expressing the membrane-bound form of anti-FRα. Bead-bound cells were single cell-sorted and processed for single cell RNA retrotranscription and PCR to isolate antibody heavy and light chain variable regions. Variable regions were then cloned and expressed as human IgG1/k antibodies. Like the original clone, engineered antibodies from single cells recognized native FRα. To evaluate whether antigen-coated beads could identify specific antibody-expressing cells in mixed immune cell populations, human peripheral blood mononuclear cells (PBMCs) were spiked with test antibody-expressing cells. Antigen-specific cells could comprise up to 75% of cells selected with antigen-conjugated beads when the frequency of the antigen-positive cells was 1:100 or higher. In PBMC pools, beads conjugated to recombinant antigens FRα and HER2 bound antigen-specific anti-FRα MOv18 and anti-HER2 Trastuzumab antibody-expressing cells, respectively. From melanoma patient-derived B cells selected with melanoma cell line-derived protein-coated fluorescent beads, we generated a monoclonal antibody that recognized melanoma antigen-coated beads. This approach may be further developed to facilitate analysis of B cells and their antibody profiles at the single cell level and to help unravel humoral immune repertoires.

Evaluation of Antigen-Conjugated Fluorescent Beads to Identify Antigen-Specific B Cells

Science.gov (United States)

Correa, Isabel; Ilieva, Kristina M.; Crescioli, Silvia; Lombardi, Sara; Figini, Mariangela; Cheung, Anthony; Spicer, James F.; Tutt, Andrew N. J.; Nestle, Frank O.; Karagiannis, Panagiotis; Lacy, Katie E.; Karagiannis, Sophia N.

2018-01-01

Selection of single antigen-specific B cells to identify their expressed antibodies is of considerable interest for evaluating human immune responses. Here, we present a method to identify single antibody-expressing cells using antigen-conjugated fluorescent beads. To establish this, we selected Folate Receptor alpha (FRα) as a model antigen and a mouse B cell line, expressing both the soluble and the membrane-bound forms of a human/mouse chimeric antibody (MOv18 IgG1) specific for FRα, as test antibody-expressing cells. Beads were conjugated to FRα using streptavidin/avidin-biotin bridges and used to select single cells expressing the membrane-bound form of anti-FRα. Bead-bound cells were single cell-sorted and processed for single cell RNA retrotranscription and PCR to isolate antibody heavy and light chain variable regions. Variable regions were then cloned and expressed as human IgG1/k antibodies. Like the original clone, engineered antibodies from single cells recognized native FRα. To evaluate whether antigen-coated beads could identify specific antibody-expressing cells in mixed immune cell populations, human peripheral blood mononuclear cells (PBMCs) were spiked with test antibody-expressing cells. Antigen-specific cells could comprise up to 75% of cells selected with antigen-conjugated beads when the frequency of the antigen-positive cells was 1:100 or higher. In PBMC pools, beads conjugated to recombinant antigens FRα and HER2 bound antigen-specific anti-FRα MOv18 and anti-HER2 Trastuzumab antibody-expressing cells, respectively. From melanoma patient-derived B cells selected with melanoma cell line-derived protein-coated fluorescent beads, we generated a monoclonal antibody that recognized melanoma antigen-coated beads. This approach may be further developed to facilitate analysis of B cells and their antibody profiles at the single cell level and to help unravel humoral immune repertoires. PMID:29628923

Humoral immunity to memory antigens and pathogens is maintained in patients with chronic kidney disease.

Science.gov (United States)

Wall, Nadezhda A; Dominguez-Medina, C Coral; Faustini, Sian E; Cook, Charlotte N; McClean, Andrew; Jesky, Mark D; Perez-Toledo, Marisol; Morgan, Matthew D; Richter, Alexandra G; Ferro, Charles J; Cockwell, Paul; Moss, Paul A; Henderson, Ian R; Harper, Lorraine; Cunningham, Adam F

2018-01-01

Patients with chronic kidney disease (CKD) have an increased risk of infection and poorer responses to vaccination. This suggests that CKD patients have an impaired responsiveness to all antigens, even those first encountered before CKD onset. To examine this we evaluated antibody responses against two childhood vaccine antigens, tetanus (TT) and diphtheria toxoids (DT) and two common pathogens, cytomegalovirus (CMV) and Salmonella enterica serovar Enteritidis (SEn) in two independent cohorts consisting of age-matched individuals with and without CKD. Sera were evaluated for antigen-specific IgG titres and the functionality of antibody to SEn was assessed in a serum bactericidal assay. Surprisingly, patients with CKD and control subjects had comparable levels of IgG against TT and DT, suggesting preserved humoral memory responses to antigens encountered early in life. Lipopolysaccharide-specific IgG titres and serum bactericidal activity in patients with CKD were also not inferior to controls. CMV-specific IgG titres in seropositive CKD patients were similar or even increased compared to controls. Therefore, whilst responses to new vaccines in CKD are typically lower than expected, antibody responses to antigens commonly encountered prior to CKD onset are not. The immunodeficiency of CKD is likely characterised by failure to respond to new antigenic challenges and efforts to improve patient outcomes should be focussed here.

Intranasal immunization with protective antigen of Bacillus anthracis induces a long-term immunological memory response.

Science.gov (United States)

Woo, Sun-Je; Kang, Seok-Seong; Park, Sung-Moo; Yang, Jae Seung; Song, Man Ki; Yun, Cheol-Heui; Han, Seung Hyun

2015-10-01

Although intranasal vaccination has been shown to be effective for the protection against inhalational anthrax, establishment of long-term immunity has yet to be achieved. Here, we investigated whether intranasal immunization with recombinant protective antigen (rPA) of Bacillus anthracis induces immunological memory responses in the mucosal and systemic compartments. Intranasal immunization with rPA plus cholera toxin (CT) sustained PA-specific antibody responses for 6 months in lung, nasal washes, and vaginal washes as well as serum. A significant induction of PA-specific memory B cells was observed in spleen, cervical lymph nodes (CLNs) and lung after booster immunization. Furthermore, intranasal immunization with rPA plus CT remarkably generated effector memory CD4(+) T cells in the lung. PA-specific CD4(+) T cells preferentially increased the expression of Th1- and Th17-type cytokines in lung, but not in spleen or CLNs. Collectively, the intranasal immunization with rPA plus CT promoted immunologic memory responses in the mucosal and systemic compartments, providing long-term immunity. Copyright © 2015 Elsevier Ltd. All rights reserved.

Therapeutic limitations in tumor-specific CD8+ memory T cell engraftment

International Nuclear Information System (INIS)

Bathe, Oliver F; Dalyot-Herman, Nava; Malek, Thomas R

2003-01-01

Adoptive immunotherapy with cytotoxic T lymphocytes (CTL) represents an alternative approach to treating solid tumors. Ideally, this would confer long-term protection against tumor. We previously demonstrated that in vitro-generated tumor-specific CTL from the ovalbumin (OVA)-specific OT-I T cell receptor transgenic mouse persisted long after adoptive transfer as memory T cells. When recipient mice were challenged with the OVA-expressing E.G7 thymoma, tumor growth was delayed and sometimes prevented. The reasons for therapeutic failures were not clear. OT-I CTL were adoptively transferred to C57BL/6 mice 21 – 28 days prior to tumor challenge. At this time, the donor cells had the phenotypical and functional characteristics of memory CD8+ T cells. Recipients which developed tumor despite adoptive immunotherapy were analyzed to evaluate the reason(s) for therapeutic failure. Dose-response studies demonstrated that the degree of tumor protection was directly proportional to the number of OT-I CTL adoptively transferred. At a low dose of OT-I CTL, therapeutic failure was attributed to insufficient numbers of OT-I T cells that persisted in vivo, rather than mechanisms that actively suppressed or anergized the OT-I T cells. In recipients of high numbers of OT-I CTL, the E.G7 tumor that developed was shown to be resistant to fresh OT-I CTL when examined ex vivo. Furthermore, these same tumor cells no longer secreted a detectable level of OVA. In this case, resistance to immunotherapy was secondary to selection of clones of E.G7 that expressed a lower level of tumor antigen. Memory engraftment with tumor-specific CTL provides long-term protection against tumor. However, there are several limitations to this immunotherapeutic strategy, especially when targeting a single antigen. This study illustrates the importance of administering large numbers of effectors to engraft sufficiently efficacious immunologic memory. It also demonstrates the importance of targeting several

Evaluation of Antigen-Specific IgM and IgG Production during an In Vitro Peripheral Blood Mononuclear Cell Culture Assay

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Yoshiko Matsuda

2017-07-01

Full Text Available The recent attention given to diseases associated with memory B-cell (mBC-produced antibodies (Abs suggests the need for a similar in vitro assay to evaluate the functions of mBCs. Here, we cultured peripheral blood mononuclear cells (PBMCs with the intent to collect mBC-derived Abs in vitro and maintain their cell–cell contact-dependent interactions with helper T-cells. PBMCs were cultured with interleukin (IL-21, CpG-oligodeoxynucleotides (ODN, phorbol myristate acetate (PMA, and phytohemagglutinin/leucoagglutinin (PHA-L in 24-well flat-bottom plates (5 × 105 cells/well. A culture supernatant analysis of PBMCs from healthy donors (n = 10 indicated that antigen-specific IgM Ab levels in a PBMC culture supernatant might be better able to demonstrate the antigen sensitization status in a smaller peripheral blood sample, compared to IgG because Epstein–Barr virus-specific IgM mBCs circulate peripherally at a significantly higher frequency once antiviral humoral immunity has stabilized. Thus, our in vitro assay demonstrated the potential significance of antigen-specific IgM Ab production in the culture supernatants. Furthermore, an analysis of cultured PBMCs from allograft kidney recipients (n = 16 sensitized with de novo donor-specific human leukocyte antigen (HLA-specific Abs (DSAs showed that IgM-type HLA-specific Abs were detected mainly from the culture supernatants from PBMCs of patients with stable graft function, whereas IgG isotype HLA Abs were detectable only from patients with biopsy-proven antibody-mediated rejection. In other words, these IgG isotype Abs also represented an activated humoral immune response in vivo. Additionally, IgM- and IgG-expressing mBCs from healthy donors (n = 5 were cultured with IL-21, CpG-ODN, and a supernatant produced by stimulating CD19+ B-cell-depleted PBMCs with PHA-L and PMA in 24-well flat-bottom plates (1 × 105 cells/well, and the resulting in vitro analysis provided some

Antigen presentation by hapten-specific B lymphocytes. II. Specificity and properties of antigen-presenting B lymphocytes, and function of immunoglobulin receptors

International Nuclear Information System (INIS)

Abbas, A.K.; Haber, S.; Rock, K.L.

1985-01-01

Studies were designed to examine the ability of hapten-binding murine B lymphocytes to present hapten-protein conjugates to protein antigen-specific, Ia-restricted T cell hybridomas. BALB/c B cells specific for TNP or FITC presented hapten-modified proteins (TNP-G1 phi, TNP-OVA, or FITC-OVA) to the relevant T cell hybridomas at concentrations below 0.1 microgram/ml. Effective presentation of the same antigens by B lymphocyte-depleted splenocytes, and of unmodified proteins by either hapten-binding B cells or Ig spleen cells, required about 10(3)-to 10(4)-fold higher concentrations of antigen. The use of two different haptens and two carrier proteins showed that this extremely efficient presentation of antigen was highly specific, with hapten specificity being a property of the B cells and carrier specificity of the responding T cells. The presentation of hapten-proteins by hapten-binding B lymphocytes was radiosensitive and was not affected by the depletion of plastic-adherent cells, suggesting that conventional APCs (macrophages or dendritic cells) are not required in this phenomenon. Antigen-pulsing and antibody-blocking experiments showed that this hapten-specific antigen presentation required initial binding of antigen to surface Ig receptors. Moreover, linked recognition of hapten and carrier determinants was required, but these recognition events could be temporally separated. Finally, an antigen-processing step was found to be necessary, and this step was disrupted by ionizing radiation. These data suggest a role for B cell surface Ig in providing a specific high-affinity receptor to allow efficient uptake or focusing of antigen for its subsequent processing and presentation to T lymphocytes

Screening Immunomodulators To Skew the Antigen-Specific Autoimmune Response.

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Northrup, Laura; Sullivan, Bradley P; Hartwell, Brittany L; Garza, Aaron; Berkland, Cory

2017-01-03

Current therapies to treat autoimmune diseases often result in side effects such as nonspecific immunosuppression. Therapies that can induce antigen-specific immune tolerance provide an opportunity to reverse autoimmunity and mitigate the risks associated with global immunosuppression. In an effort to induce antigen-specific immune tolerance, co-administration of immunomodulators with autoantigens has been investigated in an effort to reprogram autoimmunity. To date, identifying immunomodulators that may skew the antigen-specific immune response has been ad hoc at best. To address this need, we utilized splenocytes obtained from mice with experimental autoimmune encephalomyelitis (EAE) in order to determine if certain immunomodulators may induce markers of immune tolerance following antigen rechallenge. Of the immunomodulatory compounds investigated, only dexamethasone modified the antigen-specific immune response by skewing the cytokine response and decreasing T-cell populations at a concentration corresponding to a relevant in vivo dose. Thus, antigen-educated EAE splenocytes provide an ex vivo screen for investigating compounds capable of skewing the antigen-specific immune response, and this approach could be extrapolated to antigen-educated cells from other diseases or human tissues.

Memory vs memory-like: The different facets of CD8+ T-cell memory in HCV infection.

Science.gov (United States)

Hofmann, Maike; Wieland, Dominik; Pircher, Hanspeter; Thimme, Robert

2018-05-01

Memory CD8 + T cells are essential in orchestrating protection from re-infection. Hallmarks of virus-specific memory CD8 + T cells are the capacity to mount recall responses with rapid induction of effector cell function and antigen-independent survival. Growing evidence reveals that even chronic infection does not preclude virus-specific CD8 + T-cell memory formation. However, whether this kind of CD8 + T-cell memory that is established during chronic infection is indeed functional and provides protection from re-infection is still unclear. Human chronic hepatitis C virus infection represents a unique model system to study virus-specific CD8 + T-cell memory formation during and after cessation of persisting antigen stimulation. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Antigen-specific murine T cell clones produce soluble interleukin 2 receptor on stimulation with specific antigens

International Nuclear Information System (INIS)

Wagner, D.K.; York-Jolley, J.; Malek, T.R.; Berzofsky, J.A.; Nelson, D.L.

1986-01-01

In this study, monoclonal antibodies were used to the murine IL 2 receptor (IL 2R) termed 3C7 and 7D4, which bind to different epitopes on the murine IL 2R, to develop an ELISA to measure soluble murine IL 2R. Surprisingly, stimulated murine spleen cells not only expressed cell-associated IL 2R, but also produced a considerable level of cellfree IL 2R in the culture supernatant fluid. To assess the fine specificity of this response, myoglobin-immune murine T cell clones were stimulated with appropriate or inappropriate antigen and syngeneic or allogeneic presenting cells. Proliferation, measured by [ 3 H] thymidine incorporation, and levels of soluble IL 2R were determined at day 4. The production of soluble IL2R displayed the same epitope fine specificity, genetic restriction, and antigen dose-response as the proliferative response. Indeed, in some cases there was sharper discrimination of epitope specificity and genetic restriction with the soluble IL 2R levels. There was also reproducible clone-to-clone variation in the amount of soluble receptor produced in response to antigen among 12 T cell clones and lines tested. In time course experiments, proliferation was greatest at day 3, whereas soluble IL 2R levels continued to rise in subsequent days. To the authors' knowledge, this is the first demonstration of release of secretion of soluble IL 2R by murine T cells, and the first demonstration of the fine specificity and genetic restriction of the induction of soluble IL 2R by specific antigen

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

OpenAIRE

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

1997-01-01

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

Impact of obesity on the predictive accuracy of prostate-specific antigen density and prostate-specific antigen in native Korean men undergoing prostate biopsy.

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Kim, Jae Heon; Doo, Seung Whan; Yang, Won Jae; Lee, Kwang Woo; Lee, Chang Ho; Song, Yun Seob; Jeon, Yoon Su; Kim, Min Eui; Kwon, Soon-Sun

2014-10-01

To evaluate the impact of obesity on the biopsy detection of prostate cancer. We retrospectively reviewed data of 1182 consecutive Korean patients (≥50 years) with serum prostate-specific antigen levels of 3-10 ng/mL who underwent initial extended 12-cores biopsy from September 2009 to March 2013. Patients who took medications that were likely to influence the prostate-specific antigen level were excluded. Receiver operating characteristic curves were plotted for prostate-specific antigen and prostate-specific antigen density predicting cancer status among non-obese and obese men. A total of 1062 patients (mean age 67.1 years) were enrolled in the analysis. A total of 230 men (21.7%) had a positive biopsy. In the overall study sample, the area under the receiver operator characteristic curve of serum prostate-specific antigen for predicting prostate cancer on biopsy were 0.584 and 0.633 for non-obese and obese men, respectively (P = 0.234). However, the area under the curve for prostate-specific antigen density in predicting cancer status showed a significant difference (non-obese 0.696, obese 0.784; P = 0.017). There seems to be a significant difference in the ability of prostate-specific antigen density to predict biopsy results between non-obese and obese men. Obesity positively influenced the overall ability of prostate-specific antigen density to predict prostate cancer. © 2014 The Japanese Urological Association.

Prostate-Specific Antigen (PSA) Test: MedlinePlus Lab Test Information

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... medlineplus.gov/labtests/prostatespecificantigenpsatest.html Prostate-Specific Antigen (PSA) Test To use the sharing features on this ... enable JavaScript. What is a prostate-specific antigen (PSA) test? A prostate-specific antigen (PSA) test measures ...

Sporothrix schenckii Immunization, but Not Infection, Induces Protective Th17 Responses Mediated by Circulating Memory CD4+ T Cells

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Alberto García-Lozano

2018-06-01

Full Text Available Sporotrichosis is a chronic subcutaneous mycosis caused by the Sporothrix schenckii species complex and it is considered an emerging opportunistic infection in countries with tropical and subtropical climates. The host’s immune response has a main role in the development of this disease. However, it is unknown the features of the memory cellular immune response that could protect against the infection. Our results show that i.d. immunization in the ears of mice with inactivated S. schenckii conidia (iC combined with the cholera toxin (CT induces a cellular immune response mediated by circulating memory CD4+ T cells, which mainly produce interleukin 17 (IL-17. These cells mediate a strong delayed-type hypersensitivity (DTH reaction. Systemic and local protection against S. schenckii was mediated by circulating CD4+ T cells. In contrast, the infection induces a potent immune response in the skin mediated by CD4+ T cells, which have an effector phenotype that preferentially produce interferon gamma (IFN-γ and mediate a transitory DTH reaction. Our findings prove the potential value of the CT as a potent skin adjuvant when combined with fungal antigens, and they also have important implications for our better understanding of the differences between the memory immune response induced by the skin immunization and those induced by the infection; this knowledge enhances our understanding of how a protective immune response against a S. schenckii infection is developed.

Highly differentiated, resting gn-specific memory CD8+ T cells persist years after infection by andes hantavirus.

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Tobias Manigold

2010-02-01

Full Text Available In man, infection with South American Andes virus (ANDV causes hantavirus cardiopulmonary syndrome (HCPS. HCPS due to ANDV is endemic in Southern Chile and much of Argentina and increasing numbers of cases are reported all over South America. A case-fatality rate of about 36% together with the absence of successful antiviral therapies urge the development of a vaccine. Although T-cell responses were shown to be critically involved in immunity to hantaviruses in mouse models, no data are available on the magnitude, specificity and longevity of ANDV-specific memory T-cell responses in patients. Using sets of overlapping peptides in IFN-gamma ELISPOT assays, we herein show in 78 Chilean convalescent patients that Gn-derived epitopes were immunodominant as compared to those from the N- and Gc-proteins. Furthermore, while the relative contribution of the N-specific response significantly declined over time, Gn-specific responses remained readily detectable ex vivo up to 13 years after the acute infection. Tetramer analysis further showed that up to 16.8% of all circulating CD3(+CD8(+ T cells were specific for the single HLA-B*3501-restricted epitope Gn(465-473 years after the acute infection. Remarkably, Gn(465-473-specific cells readily secreted IFN-gamma, granzyme B and TNF-alpha but not IL-2 upon stimulation and showed a 'revertant' CD45RA(+CD27(-CD28(-CCR7(-CD127(- effector memory phenotype, thereby resembling a phenotype seen in other latent virus infections. Most intriguingly, titers of neutralizing antibodies increased over time in 10/17 individuals months to years after the acute infection and independently of whether they were residents of endemic areas or not. Thus, our data suggest intrinsic, latent antigenic stimulation of Gn-specific T-cells. However, it remains a major task for future studies to proof this hypothesis by determination of viral antigen in convalescent patients. Furthermore, it remains to be seen whether Gn-specific T

Memory phenotype CD4 T cells undergoing rapid, nonburst-like, cytokine-driven proliferation can be distinguished from antigen-experienced memory cells.

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Souheil-Antoine Younes

2011-10-01

Full Text Available Memory phenotype (CD44(bright, CD25(negative CD4 spleen and lymph node T cells (MP cells proliferate rapidly in normal or germ-free donors, with BrdU uptake rates of 6% to 10% per day and Ki-67 positivity of 18% to 35%. The rapid proliferation of MP cells stands in contrast to the much slower proliferation of lymphocytic choriomeningitis virus (LCMV-specific memory cells that divide at rates ranging from <1% to 2% per day over the period from 15 to 60 days after LCMV infection. Anti-MHC class II antibodies fail to inhibit the in situ proliferation of MP cells, implying a non-T-cell receptor (TCR-driven proliferation. Such proliferation is partially inhibited by anti-IL-7Rα antibody. The sequence diversity of TCRβ CDR3 gene segments is comparable among the proliferating and quiescent MP cells from conventional and germ-free mice, implying that the majority of proliferating MP cells have not recently derived from a small cohort of cells that expand through multiple continuous rounds of cell division. We propose that MP cells constitute a diverse cell population, containing a subpopulation of slowly dividing authentic antigen-primed memory cells and a majority population of rapidly proliferating cells that did not arise from naïve cells through conventional antigen-driven clonal expansion.

Diabetes is associated with lower tuberculosis antigen-specific interferon gamma release in Tanzanian tuberculosis patients and non-tuberculosis controls

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Faurholt-Jepsen, Daniel; Aabye, Martine Grosos; Jensen, Andreas Vestergaard

2014-01-01

in diabetes patients and therefore the validity of interferon gamma release assays (IGRA) may be compromised. The aim of the present study was to assess the association between diabetes and Mycobacterium tuberculosis (Mtb) antigen-specific interferon gamma (IFN-γ) release in a TB endemic area among culture......-confirmed TB patients and non-TB controls. Methods: Culture-confirmed pulmonary TB patients (n = 187) and healthy non-TB neighbourhood controls (n = 190) from Mwanza, Tanzania were tested for the presence of circulating T cells recognizing Mtb antigens using an IGRA. The diabetes status of all participants...

The effect of circulating antigen on the biodistribution of the engineered human antibody hCTM01 in a nude mice model

International Nuclear Information System (INIS)

Davies, Q.; Perkins, A.C.; Frier, M.; Watson, S.; Lalani, E.N.; Symonds, E.M.

1997-01-01

Clinical studies are currently underway to assess the biodistribution and therapeutic potential of the genetically engineered human antibody hCTM01 directed against polymorphic epithelial mucin (PEM) in patients with ovarian carcinoma. The present study was undertaken to assess the effect of circulating PEM antigen on the biodistribution of the anti-PEM antibody in mice bearing MUC-1 transfected adenocarcinoma cell lines. Tumour xenografts were established from three cell lines: 413-BCR, which expressed antigen on the cell surface and also shed antigen into the circulation, E3P23, which expressed the antigen but did not shed into the circulation, and a negative control (410.4 MUCI). Groups of five mice were injected with 1.0 mg/kg antibody, imaged after 72 h and then sacrificed, followed by assay of tissue uptake. The results showed a clear difference in the tumour and liver uptake, with the non-secreting cell line showing almost twice the tumour uptake and approximately 20% of the liver uptake of the secreting cell line. (orig.). With 4 figs., 1 tab

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

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Mauro Tognon

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

Antigen-Encoding Bone Marrow Terminates Islet-Directed Memory CD8+ T-Cell Responses to Alleviate Islet Transplant Rejection

DEFF Research Database (Denmark)

Coleman, Miranda; Jessup, Claire F.; Bridge, Jennifer A.

2016-01-01

in islet transplantation, and this will extend to application of personalized approaches using stem cell–derived replacement β-cells. New approaches are required to limit memory autoimmune attack of transplanted islets or replacement β-cells. Here, we show that transfer of bone marrow encoding cognate......Islet-specific memory T cells arise early in type 1 diabetes (T1D), persist for long periods, perpetuate disease, and are rapidly reactivated by islet transplantation. As memory T cells are poorly controlled by “conventional” therapies, memory T cell–mediated attack is a substantial challenge......-cell responses, and this can alleviate destruction of antigen-expressing islets. This addresses a key challenge facing islet transplantation and, importantly, the clinical application of personalized β-cell replacement therapies using patient-derived stem cells....

Mass spectrometric characterization of circulating and functional antigens derived from piperacillin in patients with cystic fibrosis1

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Whitaker, Paul; Meng, Xiaoli; Lavergne, Sidonie N.; El-Ghaiesh, Sabah; Monshi, Manal; Earnshaw, Caroline; Peckham, Daniel; Gooi, Jimmy; Conway, Steve; Pirmohamed, Munir; Jenkins, Rosalind E.; Naisbitt, Dean J.; Park, B. Kevin

2011-01-01

A mechanistic understanding of the relationship between the chemistry of drug antigen formation and immune function is lacking. Thus, mass spectrometric methods were employed to detect and fully characterize circulating antigens derived from piperacillin in patients undergoing therapy and the nature of the drug derived-epitopes on protein which can function as an antigen to stimulate T-cells. Albumin modification with piperacillin in vitro resulted in the formation of two distinct haptens, one formed directly from piperacillin and a second in which the dioxopiperazine ring had undergone hydrolysis. Modification was time- and concentration-dependent, with selective modification of Lys541 observed at low concentrations, whereas at higher concentrations up to 13/59 lysine residues were modified, four of which (Lys190, 195, 432 and 541) were detected in patients’ plasma. Piperacillin-specific T-lymphocyte responses (proliferation, cytokines and granzyme-B release) were detected ex vivo with cells from hypersensitive patients, and analysis of incubation medium showed that modification of the same lysine residues in albumin occurred in situ. The antigenicity of piperacillin-modified albumin was confirmed by stimulation of T-cells with characterized synthetic conjugates. Analysis of minimally-modified T-cell stimulatory albumin conjugates revealed peptide sequences incorporating Lys190, 432 and 541 as principal functional epitopes for T-cells. This study has characterized the multiple haptenic structures on albumin in patients, and showed that they constitute functional antigenic determinants for T-cells. PMID:21606251

Serological diagnosis of Taenia solium in pigs: No measurable circulating antigens and antibody response following exposure to Taenia saginata oncospheres.

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Dorny, P; Dermauw, V; Van Hul, A; Trevisan, C; Gabriël, S

2017-10-15

Taenia solium taeniasis/cysticercosis is a zoonosis included in the WHO's list of neglected tropical diseases. Accurate diagnostic tools for humans and pigs are needed to monitor intervention outcomes. Currently used diagnostic tools for porcine cysticercosis all have drawbacks. Serological tests are mainly confronted with problems of specificity. More specifically, circulating antigen detecting tests cross-react with Taenia hydatigena and the possibility of transient antigens as a result of aborted infections is suspected. Furthermore, the hypothesis has been raised that hatched ingested eggs of other Taenia species may lead to a transient antibody response or to the presence of circulating antigen detectable by serological tests used for porcine cysticercosis. Here we describe the results of a study that consisted of oral administration of Taenia saginata eggs to five piglets followed by serological testing during five weeks and necropsy aiming at studying possible cross reactions in serological tests used for porcine cysticercosis. The infectivity of the eggs was verified by in vitro hatching and by experimental infection of a calf. One piglet developed acute respiratory disease and died on day 6 post infection. The remaining four piglets did not show any clinical signs until euthanasia. None of the serum samples from four piglets collected between days 0 and 35 post infection gave a positive reaction in the B158/B60 Ag-ELISA and in a commercial Western blot for antibody detection. In conclusion, this study showed that experimental exposure of four pigs to T. saginata eggs did not result in positive serologies for T. solium. These results may help interpreting serological results in monitoring of T. solium control programmes. Copyright © 2017 Elsevier B.V. All rights reserved.

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

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Marcela V Maus

2016-01-01

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

Framing Openness. The Digital Circulation of Israel's National Photographic Memory

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Nathalie Casemajor

2014-03-01

Full Text Available Since 1948, the Government Press Office of Israel has been collecting and producing an extensive archive of photographs representing the birth and development of the Israeli nation state. Digitized and published online, this archive functions as a visual memorial of Israel, an example of what Jan Assman calls “bonding memory”, a form of memory that connects individuals to a political body, and which acts to frame a collective national identity. In 2011, the copyright terms of this archive were changed to encourage the circulation and reuse of images. This decision echoes a broader trend towards the “opening” of large data sets on the Web (“open data”, “open archives”, “open government”. At the same time, the ongoing Arab-Israeli conflict and the existence of contesting narratives of the creation of Israel threaten the integrity of the official national memory. In this context, what are the conditions and limits of “opening” the national photographic archive? Examining contemporary ideology of the “open” in new media discourses and the free culture movement, this paper investigates the conditions of circulation and appropriation of memory and the role of copyright as a potential tool to control freedom of expression.

Prostate-Specific Antigen (PSA) Test

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... Cancer Prostate Cancer Screening Research Prostate-Specific Antigen (PSA) Test On This Page What is the PSA ... parts of the body before being detected. The PSA test may give false-positive or false-negative ...

African-American Men with Gleason Score 3+3=6 Prostate Cancer Produce Less Prostate Specific Antigen than Caucasian Men: A Potential Impact on Active Surveillance.

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Kryvenko, Oleksandr N; Balise, Raymond; Soodana Prakash, Nachiketh; Epstein, Jonathan I

2016-02-01

We assess the difference in prostate specific antigen production between African-American and Caucasian men with Gleason score 3+3=6 prostate cancer. We measured tumor volume in 414 consecutive radical prostatectomies from men with National Comprehensive Cancer Network(®) low risk prostate cancer (348 Caucasian, 66 African-American) who had Gleason score 3+3=6 disease at radical prostatectomy. We then compared clinical presentation, pathological findings, prostate specific antigen, prostate specific antigen density and prostate specific antigen mass (an absolute amount of prostate specific antigen in patient's circulation) between African-American and Caucasian men. The t-test and Wilcoxon rank sum were used for comparison of means. African-American and Caucasian men had similar clinical findings based on age, body mass index and prostate specific antigen. There were no statistically significant differences between the dominant tumor nodule volume and total tumor volume (mean 0.712 vs 0.665 cm(3), p=0.695) between African-American and Caucasian men. Prostates were heavier in African-American men (mean 55.4 vs 46.3 gm, p prostate tissue contributing to prostate specific antigen in African-American men, prostate specific antigen mass was not different from that of Caucasian men (mean 0.55 vs 0.558 μg, p=0.95). Prostate specific antigen density was significantly less in African-American men due to larger prostates (mean 0.09 vs 0.105, p prostate cancer produce less prostate specific antigen than Caucasian men. African-American and Caucasian men had equal serum prostate specific antigen and prostate specific antigen mass despite significantly larger prostates in African-American men with all other parameters, particularly total tumor volume, being the same. This finding has practical implications in T1c cases diagnosed with prostate cancer due to prostate specific antigen screening. Lowering the prostate specific antigen density threshold in African-American men may

Tumor endothelial markers define novel subsets of cancer-specific circulating endothelial cells associated with antitumor efficacy

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Mehran, Reza; Nilsson, Monique; Khajavi, Mehrdad; Du, Zhiqiang; Cascone, Tina; Wu, Hua Kang; Cortes, Andrea; Xu, Li; Zurita, Amado; Schier, Robert; Riedel, Bernhard; El-Zein, Randa; Heymach, John V.

2014-01-01

Circulating endothelial cells (CEC) are derived from multiple sources including bone marrow (circulating endothelial progenitors [CEP]) and established vasculature (mature CEC). Although CEC have shown promise as a biomarker for cancer patients, their utility has been limited in part by the lack of specificity for tumor vasculature and the different non-malignant causes that can impact CEC. Tumor endothelial markers (TEM) are antigens enriched in tumor vs non-malignant endothelia. We hypothesized that TEMs may be detectable on CEC and that these circulating TEM+ endothelial cells (CTEC) may be a more specific marker for cancer and tumor response than standard CEC. We found that tumor-bearing mice had a relative increase in numbers of circulating CTEC, specifically with increased levels of TEM7 and TEM8 expression. Following treatment with various vascular targeting agents, we observed a decrease in CTEC that correlated with the reductions in tumor growth. We extended these findings to human clinical samples and observed that CTEC were present in esophageal cancer and non-small cell lung cancer (NSCLC) patients (N=40) and their levels decreased after surgical resection. These results demonstrate that CTEC are detectable in preclinical cancer models and cancer patients. Further, they suggest that CTEC offer a novel cancer-associated marker that may be useful as a blood-based surrogate for assessing the presence of tumor vasculature and antiangiogenic drug activity. PMID:24626092

Characterization of antigen association with accessory cells: specific removal of processed antigens from the cell surface by phospholipases

International Nuclear Information System (INIS)

Falo, L.D. Jr.; Haber, S.I.; Herrmann, S.; Benacerraf, B.; Rock, K.L.

1987-01-01

To characterize the basis for the cell surface association of processed antigen with the antigen-presenting cell (APC) the authors analyzed its sensitivity to enzymatic digestion. Antigen-exposed APC that are treated with phospholipase and then immediately fixed lose their ability to stimulate antigen-plus-Ia-specific T-T hybridomas. This effect is seen with highly purified phospholipase A 2 and phospholipase C. In addition it is observed with three distinct antigens - ovalbumin, bovine insulin, and poly(LGlu 56 LLys 35 LPhe 9 )[(GluLysPhe)/sub n/]. The effect of phospholipases is highly specific. Identically treated APC are equivalent to control in their ability to stimulate alloreactive hybridomas specific for precisely the same Ia molecule that is corecognized by antigen-plus-Ia-specific hybrids. Furthermore, the antigen-presenting function of enzyme-treated, fixed APC can be reconstituted by the addition of exogenous in vitro processed or processing independent antigens. In parallel studies 125 I-labeled avidin was shown to specifically bind to APC that were previously exposed and allowed to process biotin-insulin. Biotin-insulin-exposed APC that are pretreated with phospholipase bind significantly less 125 I-labeled avidin than do untreated, exposed APC. Identical enzyme treatment does not reduce the binding of avidin to a biotinylated antibody already bound to class II major histocompatibility complex molecules of APC. These studies demonstrate that phospholipase effectively removes processed cell surface antigen

Radioimmunoassay for a human prostate specific antigen

International Nuclear Information System (INIS)

Machida, T.; Miki, M.; Ohishi, Y.; Kido, A.; Morikawa, J.; Ogawa, Y.

1983-01-01

As a marker for prostatic cancer, a prostate-specific antigen was purified from human prostatic tissues. Double antibody radioimmunoassay utilizing immune reaction was developed on the basis of the purified prostatic antigen (PA). Measurement results have revealed that PA radioimmunoassay is much better than prostatic acid phosphatase (PAP) radioimmunoassay in the diagnosis of prostatic cancer

Prostate-specific antigen lowering effect of metabolic syndrome is influenced by prostate volume.

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Choi, Woo Suk; Heo, Nam Ju; Paick, Jae-Seung; Son, Hwancheol

2016-04-01

To investigate the influence of metabolic syndrome on prostate-specific antigen levels by considering prostate volume and plasma volume. We retrospectively analyzed 4111 men who underwent routine check-ups including prostate-specific antigen and transrectal ultrasonography. The definition of metabolic syndrome was based on the modified Adult Treatment Panel III criteria. Prostate-specific antigen mass density (prostate-specific antigen × plasma volume / prostate volume) was calculated for adjusting plasma volume and prostate volume. We compared prostate-specific antigen and prostate-specific antigen mass density levels of participants with metabolic syndrome (metabolic syndrome group, n = 1242) and without metabolic syndrome (non-prostate-specific antigen metabolic syndrome group, n = 2869). To evaluate the impact of metabolic syndrome on prostate-specific antigen, linear regression analysis for the natural logarithm of prostate-specific antigen was used. Patients in the metabolic syndrome group had significantly older age (P prostate volume (P prostate-specific antigen (non-metabolic syndrome group vs metabolic syndrome group; 1.22 ± 0.91 vs 1.15 ± 0.76 ng/mL, P = 0.006). Prostate-specific antigen mass density in the metabolic syndrome group was still significantly lower than that in the metabolic syndrome group (0.124 ± 0.084 vs 0.115 ± 0.071 μg/mL, P = 0.001). After adjusting for age, prostate volume and plasma volume using linear regression model, the presence of metabolic syndrome was a significant independent factor for lower prostate-specific antigen (prostate-specific antigen decrease by 4.1%, P = 0.046). Prostate-specific antigen levels in patients with metabolic syndrome seem to be lower, and this finding might be affected by the prostate volume. © 2016 The Japanese Urological Association.

Specific inhibition of cytotoxic memory cells produced against uv-induced tumors in uv-irradiation mice

International Nuclear Information System (INIS)

Thorn, R.M.

1978-01-01

Cytotoxic responses of uv-irradiated mice against syngeneic uv-induced tumors were measured by using a 51 Cr-release assay to determine if uv treatment induced a specific reduction of cytotoxic activity. The in vivo and in vitro primary responses against syngeneic tumors and allogeneic cells were unaffected, as was the ''memory'' response (in vivo stimulation, in vitro restimulation) against alloantigens. In contrast, the memory response of uv-treated mice against syngeneic, uv-induced tumors was consistently and significantly depressed. The cytotoxicity generated by tumor cell stimulation in vivo or in vitro was tumor-specific and T cell-dependent. Since the primary response against syngeneic uv-induced tumors produces apparently normal amounts of tumor-specific cytotoxic activity, uv-treated mice may not reject transplanted syngeneic tumors because of too few T effector memory cells. These results imply that, at least in this system, tumor rejection depends mostly on the secondary responses against tumor antigens and that at least one carcinogen can, indirectly, specifically regulate immune responses

Experimental sepsis impairs humoral memory in mice.

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Christian Pötschke

Full Text Available Patients with sepsis are often immune suppressed, and experimental mouse models of sepsis also display this feature. However, acute sepsis in mice is also characterized by a generalized B cell activation and plasma cell differentiation, resulting in a marked increase in serum antibody concentration. Its effects on humoral memory are not clearly defined. We measured the effects of experimental sepsis on long-term immunological memory for a defined antigen: we induced colon ascendens stent peritonitis (CASP 8 weeks after 2 rounds of immunization with ovalbumin. Four weeks later, the antigen-specific bone marrow plasma cell count had doubled in immunized non-septic animals, but remained unchanged in immunized septic animals. Sepsis also caused a decrease in antigen-specific serum antibody concentration. We conclude that sepsis weakens humoral memory by impeding the antigen-specific plasma cell pool's development, which is not complete 8 weeks after secondary immunization.

Early transduction produces highly functional chimeric antigen receptor-modified virus-specific T-cells with central memory markers: a Production Assistant for Cell Therapy (PACT) translational application.

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Sun, Jiali; Huye, Leslie E; Lapteva, Natalia; Mamonkin, Maksim; Hiregange, Manasa; Ballard, Brandon; Dakhova, Olga; Raghavan, Darshana; Durett, April G; Perna, Serena K; Omer, Bilal; Rollins, Lisa A; Leen, Ann M; Vera, Juan F; Dotti, Gianpietro; Gee, Adrian P; Brenner, Malcolm K; Myers, Douglas G; Rooney, Cliona M

2015-01-01

Virus-specific T-cells (VSTs) proliferate exponentially after adoptive transfer into hematopoietic stem cell transplant (HSCT) recipients, eliminate virus infections, then persist and provide long-term protection from viral disease. If VSTs behaved similarly when modified with tumor-specific chimeric antigen receptors (CARs), they should have potent anti-tumor activity. This theory was evaluated by Cruz et al. in a previous clinical trial with CD19.CAR-modified VSTs, but there was little apparent expansion of these cells in patients. In that study, VSTs were gene-modified on day 19 of culture and we hypothesized that by this time, sufficient T-cell differentiation may have occurred to limit the subsequent proliferative capacity of the transduced T-cells. To facilitate the clinical testing of this hypothesis in a project supported by the NHLBI-PACT mechanism, we developed and optimized a good manufacturing practices (GMP) compliant method for the early transduction of VSTs directed to Epstein-Barr virus (EBV), Adenovirus (AdV) and cytomegalovirus (CMV) using a CAR directed to the tumor-associated antigen disialoganglioside (GD2). Ad-CMVpp65-transduced EBV-LCLs effectively stimulated VSTs directed to all three viruses (triVSTs). Transduction efficiency on day three was increased in the presence of cytokines and high-speed centrifugation of retroviral supernatant onto retronectin-coated plates, so that under optimal conditions up to 88% of tetramer-positive VSTs expressed the GD2.CAR. The average transduction efficiency of early-and late transduced VSTs was 55 ± 4% and 22 ± 5% respectively, and early-transduced VSTs maintained higher frequencies of T cells with central memory or intermediate memory phenotypes. Early-transduced VSTs also had higher proliferative capacity and produced higher levels of TH1 cytokines IL-2, TNF-α, IFN-γ, MIP-1α, MIP-1β and other cytokines in vitro. We developed a rapid and GMP compliant method for the early transduction of

Enhancement of Human Antigen-Specific Memory T-Cell Responses by Interleukin-7 May Improve Accuracy in Diagnosing Tuberculosis▿ †

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Feske, Marsha; Nudelman, Rodolfo J.; Medina, Miguel; Lew, Justin; Singh, Manisha; Couturier, Jacob; Graviss, Edward A.; Lewis, Dorothy E.

2008-01-01

Children and immunocompromised adults are at an increased risk of tuberculosis (TB), but diagnosis is more challenging. Recently developed gamma interferon (IFN-γ) release assays provide increased sensitivity and specificity for diagnosis of latent TB, but their use is not FDA approved in immunocompromised or pediatric populations. Both populations have reduced numbers of T cells, which are major producers of IFN-γ. Interleukin 7 (IL-7), a survival cytokine, stabilizes IFN-γ message and increases protein production. IL-7 was added to antigen-stimulated lymphocytes to improve IFN-γ responses as measured by enzyme-linked immunosorbent assay (ELISA) and enzyme-linked immunospot (ELISPOT) assay. Antigens used were tetanus toxoid (n = 10), p24 (from human immunodeficiency virus [HIV], n = 9), and TB peptides (n = 15). Keyhole limpet hemocyanin was used as a negative control, and phytohemagglutinin was the positive control. IL-7 improved antigen-specific responses to all antigens tested including tetanus toxoid, HIV type 1 p24, and TB peptides (ESAT-6 and CFP-10) with up to a 14-fold increase (mean = 3.8), as measured by ELISA. Increased IFN-γ responses from controls, HIV-positive patients, and TB patients were statistically significant, with P values of <0.05, 0.01, and 0.05, respectively. ELISPOT assay results confirmed ELISA findings (P values of <0.01, 0.02, and 0.03, respectively), with a strong correlation between the two tests (R2 = 0.82 to 0.99). Based on average background levels, IL-7 increased detection of IFN-γ by 39% compared to the level with antigen alone. Increased production of IFN-γ induced by IL-7 improves sensitivity of ELISA and ELISPOT assays for all antigens tested. Further enhancement of IFN-γ-based assays might improve TB diagnosis in those populations at highest risk for TB. PMID:18753334

A radioimmunoassay for human antibody specific for microbial antigens

International Nuclear Information System (INIS)

Tew, J.G.; Burmeister, J.; Greene, E.J.; Pflaumer, S.K.; Goldstein, J.

1977-01-01

A simple and sensitive method for detecting and quantitating antibody specific or microbial antigens is described. Bacterial, fungal, parasitic or viral antigens attached to bromoacetyl cellulose or the intact cells themselves were added to a series of two-fold dilutions of human serum. After a short incubation period, which allowed human antibody to attach to the antigens, the complex was thoroughly washed and carbon-14 labeled anti-human light chain antibody was added to each dilution. The resulting complex was washed, collected on a filter pad, placed in a scintillation vial and radioassayed. The relationship between radioactivity bound and -log 2 of the serum dilution was linear. The endpoint for each assay and a confidence interval was calculated by doing inverse prediction from simple linear regression. Results obtained using this assay indicated the presence of antibody in a pool of normal human sera specific for herpes virus and for both cell surface and intracellular antigens of Streptococcus mutans, Naegleria fowleri and Cryptococcus neoformans. In general the dominant response was against the intracellular antigens rather than cell surface antigens

Focal radiation therapy combined with 4-1BB activation and CTLA-4 blockade yields long-term survival and a protective antigen-specific memory response in a murine glioma model.

Directory of Open Access Journals (Sweden)

Zineb Belcaid

Full Text Available Glioblastoma (GBM is the most common malignant brain tumor in adults and is associated with a poor prognosis. Cytotoxic T lymphocyte antigen -4 (CTLA-4 blocking antibodies have demonstrated an ability to generate robust antitumor immune responses against a variety of solid tumors. 4-1BB (CD137 is expressed by activated T lymphocytes and served as a co-stimulatory signal, which promotes cytotoxic function. Here, we evaluate a combination immunotherapy regimen involving 4-1BB activation, CTLA-4 blockade, and focal radiation therapy in an immune-competent intracranial GBM model.GL261-luciferace cells were stereotactically implanted in the striatum of C57BL/6 mice. Mice were treated with a triple therapy regimen consisted of 4-1BB agonist antibodies, CTLA-4 blocking antibodies, and focal radiation therapy using a small animal radiation research platform and mice were followed for survival. Numbers of brain-infiltrating lymphocytes were analyzed by FACS analysis. CD4 or CD8 depleting antibodies were administered to determine the relative contribution of T helper and cytotoxic T cells in this regimen. To evaluate the ability of this immunotherapy to generate an antigen-specific memory response, long-term survivors were re-challenged with GL261 glioma en B16 melanoma flank tumors.Mice treated with triple therapy had increased survival compared to mice treated with focal radiation therapy and immunotherapy with 4-1BB activation and CTLA-4 blockade. Animals treated with triple therapy exhibited at least 50% long-term tumor free survival. Treatment with triple therapy resulted in a higher density of CD4+ and CD8+ tumor infiltrating lymphocytes. Mechanistically, depletion of CD4+ T cells abrogated the antitumor efficacy of triple therapy, while depletion of CD8+ T cells had no effect on the treatment response.Combination therapy with 4-1BB activation and CTLA-4 blockade in the setting of focal radiation therapy improves survival in an orthotopic mouse

Dynamics of antigen presentation to transgene product-specific CD4+ T cells and of Treg induction upon hepatic AAV gene transfer

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George Q Perrin

2016-01-01

Full Text Available The tolerogenic hepatic microenvironment impedes clearance of viral infections but is an advantage in viral vector gene transfer, which often results in immune tolerance induction to transgene products. Although the underlying tolerance mechanism has been extensively studied, our understanding of antigen presentation to transgene product-specific CD4+ T cells remains limited. To address this, we administered hepatotropic adeno-associated virus (AAV8 vector expressing cytoplasmic ovalbumin (OVA into wt mice followed by adoptive transfer of transgenic OVA-specific T cells. We find that that the liver-draining lymph nodes (celiac and portal are the major sites of MHC II presentation of the virally encoded antigen, as judged by in vivo proliferation of DO11.10 CD4+ T cells (requiring professional antigen-presenting cells, e.g., macrophages and CD4+CD25+FoxP3+ Treg induction. Antigen presentation in the liver itself contributes to activation of CD4+ T cells egressing from the liver. Hepatic-induced Treg rapidly disseminate through the systemic circulation. By contrast, a secreted OVA transgene product is presented in multiple organs, and OVA-specific Treg emerge in both the thymus and periphery. In summary, liver draining lymph nodes play an integral role in hepatic antigen presentation and peripheral Treg induction, which results in systemic regulation of the response to viral gene products.

Partial reconstitution of virus-specific memory CD8+ T cells following whole body γ-irradiation

International Nuclear Information System (INIS)

Grayson, Jason M.; Laniewski, Nathan G.; Holbrook, Beth C.

2006-01-01

CD8 + memory T cells are critical in providing immunity to viral infection. Previous studies documented that antigen-specific CD8 + memory T cells are more resistant to radiation-induced apoptosis than naive T cells. Here, we determined the number and in vivo function of memory CD8 + T cells as immune reconstitution progressed following irradiation. Immediately following irradiation, the number of memory CD8 + T cells declined 80%. As reconstitution progressed, the number of memory cells reached a zenith at 33% of pre-irradiation levels, and was maintained for 120 days post-irradiation. In vitro, memory CD8 + T cells were able to produce cytokines at all times post-irradiation, but when adoptively transferred, they were not able to expand upon rechallenge immediately following irradiation, but regained this ability as reconstitution progressed. When proliferation was examined in vitro, irradiated memory CD8 + T cells were able to respond to mitogenic growth but were unable to divide

Molecular Epidemiology and Antigenic Characterization of Seasonal Influenza Viruses Circulating in Nepal.

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Upadhyay, B P; Ghimire, P; Tashiro, M; Banjara, M R

2017-01-01

Influenza is one of the public health burdens in Nepal and its epidemiology is not clearly understood. The objective of this study was to explore the molecular epidemiology and the antigenic characteristics of the circulating influenza viruses in Nepal. A total of 1495 throat swab specimens were collected from January to December, 2014. Real time PCR assay was used for identification of influenza virus types and subtypes. Ten percent of the positive specimens were randomly selected and inoculated onto Madin-Darby Canine Kidney Epithelial cells (MDCK) for influenza virus isolation. All viruses were characterized by the hemagglutination inhibition (HI) assay. Influenza viruses were detected in 421/1495 (28.2%) specimens. Among positive cases, influenza A virus was detected in 301/421 (71.5%); of which 120 (39.9%) were influenza A/H1N1 pdm09 and 181 (60.1%) were influenza A/H3 subtype. Influenza B viruses were detected in 119/421 (28.3%) specimens. Influenza A/H1N1 pdm09, A/H3 and B viruses isolated in Nepal were antigenically similar to the vaccine strain influenza A/California/07/2009(H1N1pdm09), A/Texas/50/2012(H3N2), A/New York/39/2012(H3N2) and B/Massachusetts/2/2012, respectively. Influenza viruses were reported year-round in different geographical regions of Nepal which was similar to other tropical countries. The circulating influenza virus type and subtypes of Nepal were similar to vaccine candidate virus which could be prevented by currently used influenza vaccine.

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

Circulating MicroRNAs in Plasma of Hepatitis B e Antigen Positive Children Reveal Liver-Specific Target Genes

DEFF Research Database (Denmark)

Winther, Thilde Nordmann; Jacobsen, Kari Stougaard; Mirza, Aashiq Hussain

2014-01-01

Background and Aim. Hepatitis B e antigen positive (HBeAg-positive) children are at high risk of severe complications such as hepatocellular carcinoma and cirrhosis. Liver damage is caused by the host immune response to infected hepatocytes, and we hypothesise that specific microRNAs play a role...... in this complex interaction between virus and host. The study aimed to identify microRNAs with aberrant plasma expressions in HBeAg-positive children and with liver-specific target genes. Methods. By revisiting our previous screen of microRNA plasma levels in HBeAg-positive and HBeAg-negative children...... with chronic hepatitis B (CHB) and in healthy controls, candidate microRNAs with aberrant plasma expressions in HBeAg-positive children were identified. MicroRNAs targeting liver-specific genes were selected based on bioinformatics analysis and validated by qRT-PCR using plasma samples from 34 HBe...

Prediagnostic prostate-specific antigen kinetics and the risk of biopsy progression in active surveillance patients.

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Iremashvili, Viacheslav; Barney, Shane L; Manoharan, Murugesan; Kava, Bruce R; Parekh, Dipen J; Punnen, Sanoj

2016-04-01

To analyze the association between prediagnostic prostate-specific antigen kinetics and the risk of biopsy progression in prostate cancer patients on active surveillance, and to study the effect of prediagnostic prostate-specific antigen values on the predictive performance of prostate-specific antigen velocity and prostate-specific antigen doubling time. The study included 137 active surveillance patients with two or more prediagnostic prostate-specific antigen levels measured over a period of at least 3 months. Two sets of analyses were carried out. First, the association between prostate-specific antigen kinetics calculated using only the prediagnostic prostate-specific antigen values and the risk of biopsy progression was studied. Second, using the same cohort of patients, the predictive value of prostate-specific antigen kinetics calculated using only post-diagnostic prostate-specific antigens and compared with that of prostate-specific antigen kinetics based on both pre- and post-diagnostic prostate-specific antigen levels was analyzed. Of 137 patients included in the analysis, 37 (27%) had biopsy progression over a median follow-up period of 3.2 years. Prediagnostic prostate-specific antigen velocity of more than 2 ng/mL/year and 3 ng/mL/year was statistically significantly associated with the risk of future biopsy progression. However, after adjustment for baseline prostate-specific antigen density, these associations were no longer significant. None of the tested prostate-specific antigen kinetics based on combined pre- and post-diagnostic prostate-specific antigen values were statistically significantly associated with the risk of biopsy progression. Historical prediagnostic prostate-specific antigens seems to be not clinically useful in patients diagnosed with low-risk prostate cancer on active surveillance. © 2016 The Japanese Urological Association.

Antigen specific T-cell responses against tumor antigens are controlled by regulatory T cells in patients with prostate cancer.

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Hadaschik, Boris; Su, Yun; Huter, Eva; Ge, Yingzi; Hohenfellner, Markus; Beckhove, Philipp

2012-04-01

Immunotherapy is a promising approach in an effort to control castration resistant prostate cancer. We characterized tumor antigen reactive T cells in patients with prostate cancer and analyzed the suppression of antitumor responses by regulatory T cells. Peripheral blood samples were collected from 57 patients with histologically confirmed prostate cancer, 8 patients with benign prostatic hyperplasia and 16 healthy donors. Peripheral blood mononuclear cells were isolated and antigen specific interferon-γ secretion of isolated T cells was analyzed by enzyme-linked immunospot assay. T cells were functionally characterized and T-cell responses before and after regulatory T-cell depletion were compared. As test tumor antigens, a panel of 11 long synthetic peptides derived from a total of 8 tumor antigens was used, including prostate specific antigen and prostatic acid phosphatase. In patients with prostate cancer we noted a 74.5% effector T-cell response rate compared with only 25% in patients with benign prostatic hyperplasia and 31% in healthy donors. In most patients 2 or 3 tumor antigens were recognized. Comparing various disease stages there was a clear increase in the immune response against prostate specific antigens from intermediate to high risk tumors and castration resistant disease. Regulatory T-cell depletion led to a significant boost in effector T-cell responses against prostate specific antigen and prostatic acid phosphatase. Tumor specific effector T cells were detected in most patients with prostate cancer, especially those with castration resistant prostate cancer. Since effector T-cell responses against prostate specific antigens strongly increased after regulatory T-cell depletion, our results indicate that immunotherapy efficacy could be enhanced by decreasing regulatory T cells. Copyright © 2012 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Rapid desensitization induces internalization of antigen-specific IgE on mouse mast cells.

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Oka, Tatsuya; Rios, Eon J; Tsai, Mindy; Kalesnikoff, Janet; Galli, Stephen J

2013-10-01

Rapid desensitization transiently prevents severe allergic reactions, allowing administration of life-saving therapies in previously sensitized patients. However, the mechanisms underlying successful rapid desensitization are not fully understood. We sought to investigate whether the mast cell (MC) is an important target of rapid desensitization in mice sensitized to exhibit IgE-dependent passive systemic anaphylaxis in vivo and to investigate the antigen specificity and underlying mechanisms of rapid desensitization in our mouse model. C57BL/6 mice (in vivo) or primary isolated C57BL/6 mouse peritoneal mast cells (PMCs; in vitro) were passively sensitized with antigen-specific anti-2,4-dinitrophenyl IgE, anti-ovalbumin IgE, or both. MCs were exposed over a short period of time to increasing amounts of antigen (2,4-dinitrophenyl-human serum albumin or ovalbumin) in the presence of extracellular calcium in vitro or by means of intravenous administration to sensitized mice in vivo before challenging the mice with or exposing the PMCs to optimal amounts of specific or irrelevant antigen. Rapidly exposing mice or PMCs to progressively increasing amounts of specific antigen inhibited the development of antigen-induced hypothermia in sensitized mice in vivo and inhibited antigen-induced PMC degranulation and prostaglandin D2 synthesis in vitro. Such MC hyporesponsiveness was induced antigen-specifically and was associated with a significant reduction in antigen-specific IgE levels on MC surfaces. Rapidly exposing MCs to progressively increasing amounts of antigen can both enhance the internalization of antigen-specific IgE on the MC surface and also desensitize these cells in an antigen-specific manner in vivo and in vitro. Copyright © 2013 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

Detection of Avian Antigen-Specific T Cells Induced by Viral Vaccines

DEFF Research Database (Denmark)

Dalgaard, Tina Sørensen; Norup, Liselotte Rothmann; Juul-Madsen, Helle Risdahl

2016-01-01

Live attenuated viral vaccines are widely used in commercial poultry production, but the development of new effective inactivated/subunit vaccines is needed. Studies of avian antigen-specific T cells are primarily based on analyses ex vivo after activating the cells with recall antigen. There is ......Live attenuated viral vaccines are widely used in commercial poultry production, but the development of new effective inactivated/subunit vaccines is needed. Studies of avian antigen-specific T cells are primarily based on analyses ex vivo after activating the cells with recall antigen...

Generation of Tumor Antigen-Specific iPSC-Derived Thymic Emigrants Using a 3D Thymic Culture System

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Raul Vizcardo

2018-03-01

Full Text Available Summary: Induced pluripotent stem cell (iPSC-derived T cells may provide future therapies for cancer patients, but those generated by current methods, such as the OP9/DLL1 system, have shown abnormalities that pose major barriers for clinical translation. Our data indicate that these iPSC-derived CD8 single-positive T cells are more like CD4+CD8+ double-positive T cells than mature naive T cells because they display phenotypic markers of developmental arrest and an innate-like phenotype after stimulation. We developed a 3D thymic culture system to avoid these aberrant developmental fates, generating a homogeneous subset of CD8αβ+ antigen-specific T cells, designated iPSC-derived thymic emigrants (iTEs. iTEs exhibit phenotypic and functional similarities to naive T cells both in vitro and in vivo, including the capacity for expansion, memory formation, and tumor suppression. These data illustrate the limitations of current methods and provide a tool to develop the next generation of iPSC-based antigen-specific immunotherapies. : A barrier for clinical application of iPSC-derived CD8 T cells using OP9/DLL1 is their abnormal biology. Vizcardo et al. show that a 3D thymic culture system enables the generation of a homogeneous antigen-specific T cell subset, named iTEs, which closely mimics naive T cells and exhibits potent anti-tumor activity. Keywords: thymopoiesis, T cell differentiation, iPSC differentiation, adoptive cell transfer, naïve T cell, recent rhymic emigrants, fetal thymus organ culture, immunotherapy, 3D culture, tumor antigen specific T cell

Antigenic and genomic characterization of human influenza A and B viruses circulating in Argentina after the introduction of influenza A(H1N1)pdm09.

Science.gov (United States)

Russo, Mara L; Pontoriero, Andrea V; Benedetti, Estefania; Czech, Andrea; Avaro, Martin; Periolo, Natalia; Campos, Ana M; Savy, Vilma L; Baumeister, Elsa G

2014-12-01

This study was conducted as part of the Argentinean Influenza and other Respiratory Viruses Surveillance Network, in the context of the Global Influenza Surveillance carried out by the World Health Organization (WHO). The objective was to study the activity and the antigenic and genomic characteristics of circulating viruses for three consecutive seasons (2010, 2011 and 2012) in order to investigate the emergence of influenza viral variants. During the study period, influenza virus circulation was detected from January to December. Influenza A and B, and all current subtypes of human influenza viruses, were present each year. Throughout the 2010 post-pandemic season, influenza A(H1N1)pdm09, unexpectedly, almost disappeared. The haemagglutinin (HA) of the A(H1N1)pdm09 viruses studied were segregated in a different genetic group to those identified during the 2009 pandemic, although they were still antigenically closely related to the vaccine strain A/California/07/2009. Influenza A(H3N2) viruses were the predominant strains circulating during the 2011 season, accounting for nearly 76 % of influenza viruses identified. That year, all HA sequences of the A(H3N2) viruses tested fell into the A/Victoria/208/2009 genetic clade, but remained antigenically related to A/Perth/16/2009 (reference vaccine recommended for this three-year period). A(H3N2) viruses isolated in 2012 were antigenically closely related to A/Victoria/361/2011, recommended by the WHO as the H3 component for the 2013 Southern Hemisphere formulation. B viruses belonging to the B/Victoria lineage circulated in 2010. A mixed circulation of viral variants of both B/Victoria and B/Yamagata lineages was detected in 2012, with the former being predominant. A(H1N1)pdm09 viruses remained antigenically closely related to the vaccine virus A/California/7/2009; A(H3N2) viruses continually evolved into new antigenic clusters and both B lineages, B/Victoria/2/87-like and B/Yamagata/16/88-like viruses, were observed

The value of prostate specific antigen and prostate specific antigen density in the diagnosis ad treatment of prostate cancer

International Nuclear Information System (INIS)

Hu Guoying; Yu Mingqi; Feng Xinli

2001-01-01

To study the clinical value of prostate specific antigen (PSA) and prostate specific antigen density (PSAD), the PSA levels of pre-and post-treatment were measured in 28 cases with prostate cancer (Pca) and 80 patients with being Prostate hyperplasia (BPH). PASD was measured in 18 cases Pca and 50 cases BPH of them. The results suggest that the sensitivity, specificity and accuracy of diagnosis for Pca were 85.7%, 80.0% and 81.4%, respectively. The false positive rate was 20%. PSAD is superior to PSA in distinguishing prostate cancer from benign prostate hyperplasia. The false positive rate was only 6%. But in the clinical application, the authors should combine PASD with other materials. The regular observation of post therapeutic PSA is of great value to the earlier discovery of local recurrence and metastasis as well as the judgement of curative effect and prognosis

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

NARCIS (Netherlands)

S.U. de Willige; Keane, F.M. (Fiona M.); Bowen, D.G. (David G.); J.J.M.C. Malfliet (Joyce); Zhang, H.E. (H. Emma); Maneck, B. (Bharvi); G. McCaughan (Geoff); F.W.G. Leebeek (Frank); D.C. Rijken (Dingeman); Gorrell, M.D. (Mark D.)

2017-01-01

textabstractBackground and aim: 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

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

International Nuclear Information System (INIS)

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

2004-01-01

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

Shaping the CD4+ memory immune response against tuberculosis: the role of antigen persistence, location and multi-functionality.

Science.gov (United States)

Ancelet, Lindsay; Kirman, Joanna

2012-02-01

Abstract Effective vaccination against intracellular pathogens, such as tuberculosis (TB), relies on the generation and maintenance of CD4 memory T cells. An incomplete understanding of the memory immune response has hindered the rational design of a new, more effective TB vaccine. This review discusses how the persistence of antigen, the location of memory cells, and their multifunctional ability shape the CD4 memory T cell response against TB.

Tethered IL-15 augments antitumor activity and promotes a stem-cell memory subset in tumor-specific T cells.

Science.gov (United States)

Hurton, Lenka V; Singh, Harjeet; Najjar, Amer M; Switzer, Kirsten C; Mi, Tiejuan; Maiti, Sourindra; Olivares, Simon; Rabinovich, Brian; Huls, Helen; Forget, Marie-Andrée; Datar, Vrushali; Kebriaei, Partow; Lee, Dean A; Champlin, Richard E; Cooper, Laurence J N

2016-11-29

Adoptive immunotherapy retargeting T cells to CD19 via a chimeric antigen receptor (CAR) is an investigational treatment capable of inducing complete tumor regression of B-cell malignancies when there is sustained survival of infused cells. T-memory stem cells (T SCM ) retain superior potential for long-lived persistence, but challenges exist in manufacturing this T-cell subset because they are rare among circulating lymphocytes. We report a clinically relevant approach to generating CAR + T cells with preserved T SCM potential using the Sleeping Beauty platform. Because IL-15 is fundamental to T-cell memory, we incorporated its costimulatory properties by coexpressing CAR with a membrane-bound chimeric IL-15 (mbIL15). The mbIL15-CAR T cells signaled through signal transducer and activator of transcription 5 to yield improved T-cell persistence independent of CAR signaling, without apparent autonomous growth or transformation, and achieved potent rejection of CD19 + leukemia. Long-lived T cells were CD45RO neg CCR7 + CD95 + , phenotypically most similar to T SCM , and possessed a memory-like transcriptional profile. Overall, these results demonstrate that CAR + T cells can develop long-term persistence with a memory stem-cell phenotype sustained by signaling through mbIL15. This observation warrants evaluation in clinical trials.

Prostate specific antigen in boys with precocious puberty before and during gonadal suppression by GnRH agonist treatment

DEFF Research Database (Denmark)

Juul, A; Müller, J; Skakkebaek, N E

1997-01-01

antigen (PSA) is a marker of the androgen-dependent prostatic epithelial cell activity and it is used in the diagnosis and surveillance of adult patients with prostatic cancer. We have measured PSA concentrations in serum from boys with precocious puberty before and during gonadal suppression with Gn......In healthy boys, the pituitary-gonadal axis exhibits diurnal variation in early puberty. Serum testosterone levels are higher during the night and low or immeasurable during the day. These fluctuating levels of circulating androgens in early pubertal boys are difficult to monitor. Prostate specific...

Radioimmunoassay for tumor antigen of human cervical squamous cell carcinoma

International Nuclear Information System (INIS)

Kato, H.; Torigoe, T.

1977-01-01

A heterologous antiserum for human cervical squamous cell carcinoma was prepared and specificity determined by Ouchterlony immunodiffusion and immunofluorescence studies. With this antiserum, a tumor antigen was purified from human cervical squamous cell carcinoma tissue. The specificities of the antigen and the antiserum were then re-examined by a radioimmunoassay method using 125 I-labeled purified antigen. Although normal cervical tissue extract showed a moderate cross-reactivity in the radioimmunoassay, the circulating antigen activity could not be detected in normal women or in several patients with other carcinomas, whereas 27 of 35 patients with cervical squamous cell carcinoma showed detectable serum antigen activity. All patients with advanced stages of cervical squamous cell carcinoma showed detectable antigen levels. These results indicate that there is a quantitative abnormality, at least, of this tumor antigen in patients with cervical squamous cell carcinoma and that the radioimmunoassay for the antigen is a potentially useful tool in clinical care

Individual differences in susceptibility to false memories: The effect of memory specificity.

Science.gov (United States)

Dewhurst, Stephen A; Anderson, Rachel J; Berry, Donna M; Garner, Sarah R

2017-06-25

Previous research has highlighted the wide individual variability in susceptibility to the false memories produced by the Deese/Roediger-McDermott (DRM) procedure [Deese, J. (1959). On the prediction of occurrence of particular verbal intrusions in immediate recall. Journal of Experimental Psychology, 58, 17-22; Roediger, H. L., III, & McDermott, K. B. (1995). Creating false memories: Remembering words not presented in lists. Journal of Experimental Psychology: Learning, Memory, & Cognition, 21, 803-814]. The current study investigated whether susceptibility to false memories is influenced by individual differences in the specificity of autobiographical memory retrieval. Memory specificity was measured using the Sentence Completion for Events from the Past Test (SCEPT) [Raes, F., Hermans, D., Williams, J. M. G., & Eelen, P. (2007). A sentence completion procedure as an alternative to the Autobiographical Memory Test for assessing overgeneral memory in non-clinical populations. Memory, 15, 495-507]. Memory specificity did not correlate with correct recognition, but a specific retrieval style was positively correlated with levels of false recognition. It is proposed that the contextual details that frequently accompany false memories of nonstudied lures are more accessible in individuals with specific retrieval styles.

Kinetics of antigen specific and non-specific polyclonal B-cell responses during lethal Plasmodium yoelii malaria

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Laurence Rolland

1992-06-01

Full Text Available In order to study the kinetics and composition of the polyclonal B-cell activation associated to malaria infection, antigen-specific and non-specific B-cell responses were evaluated in the spleens of mice infected with Plasmodium yoelii 17 XL or injected with lysed erythrocytes or plasma from P. yoelii infected mice or with P. falciparum culture supernatants. Spleen/body weigth ratio, numbers of nucleated spleen cells and Immunoglobulin-containing and Immunoglobulin-secreting cells increased progressively during the course of infection,in parallel to the parasitemia. A different pattern of kinetics was observed when anti-sheep red blood cell and anti-trinitrophenylated-sheep red blood cell plaque forming cells response were studied: maximum values were observed at early stages of infection, whereas the number of total Immunoglobulin-containing and Immunoglobulin-secreting cells were not yet altered. Conversely, at the end of infection, when these latter values reached their maximum, the anti-sheep red blood cell and anti-trinitrophenylated-sheep red blood cell specific responses were normal or even infranormal. In mice injected with Plasmodium-derived material, a higher increase in antigen-specific PFC was observed, as compared to the increase of Immunoglobulin-containing and Immunoglobulin-secreting cell numbers. This suggested a "preferential" (antigen-plus mitogen-induced stimulation of antigen-specific cells rather than a generalized non-specific (mitogen-induced triggering of B-lymphocytes. On the basis of these and previous results, it is suggested that polyclonal B-cell activation that takes place during the course of infection appears as a result of successive waves of antigen-specific B-cell activation.

Comparative efficacy of antigen and antibody detection tests for human trichinellosis

International Nuclear Information System (INIS)

Ivanoska, D.; Cuperlovic, K.; Gamble, H.R.; Murrell, K.D.

1989-01-01

Sera collected from patients with suspected or confirmed exposure to Trichinella spiralis were tested for circulating parasite antigens and antiparasite antibodies. Using an immunoradiometric assay, excretory--secretory antigens from muscle-stage larvae of T. spiralis were detected in the sera of 47% of 62 patients with clinical trichinellosis and 13% of 39 patients without clinical signs but suspected of exposure to infected meat. In comparison, antibodies were detected using an indirect immunofluorescent test in the circulation of 100% of the 62 patients with clinical trichinellosis and 46% of the 39 patients with suspected exposure. The presence of antibodies specific to excretory-secretory products of T. spiralis muscle larvae was confirmed in the majority of the samples tested by a monoclonal antibody-based competitive inhibition assay. These results indicate that antibody detection is a more sensitive diagnostic method for human trichinellosis, but that antigen detection might be a useful confirmatory test because it is a direct demonstration of parasite products in the circulation

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

Directory of Open Access Journals (Sweden)

Michael C. Gong

1999-06-01

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

Lipopolysaccharide-specific memory B cell responses to an attenuated live cholera vaccine are associated with protection against Vibrio cholerae infection.

Science.gov (United States)

Haney, Douglas J; Lock, Michael D; Gurwith, Marc; Simon, Jakub K; Ishioka, Glenn; Cohen, Mitchell B; Kirkpatrick, Beth D; Lyon, Caroline E; Chen, Wilbur H; Sztein, Marcelo B; Levine, Myron M; Harris, Jason B

2018-05-11

The single-dose live attenuated vaccine CVD 103-HgR protects against experimental Vibrio cholerae infection in cholera-naïve adults for at least 6 months after vaccination. While vaccine-induced vibriocidal seroconversion is associated with protection, vibriocidal titers decline rapidly from their peak 1-2 weeks after vaccination. Although vaccine-induced memory B cells (MBCs) might mediate sustained protection in individuals without detectable circulating antibodies, it is unknown whether oral cholera vaccination induces a MBC response. In a study that enrolled North American adults, we measured lipopolysaccharide (LPS)- and cholera toxin (CtxB)-specific MBC responses to PXVX0200 (derived from the CVD 103-HgR strain) and assessed stool volumes following experimental Vibrio cholerae infection. We then evaluated the association between vaccine-induced MBC responses and protection against cholera. There was a significant increase in % CT-specific IgG, % LPS-specific IgG, and % LPS-specific IgA MBCs which persisted 180 days after vaccination as well as a significant association between vaccine-induced increase in % LPS-specific IgA MBCs and lower post-challenge stool volume (r = -0.56, p < 0.001). Oral cholera vaccination induces antigen-specific MBC responses, and the anamnestic LPS-specific responses may contribute to long-term protection and provide correlates of the duration of vaccine-induced protection. NCT01895855. Copyright © 2018 The Author(s). Published by Elsevier Ltd.. All rights reserved.

The Importance of Memory Specificity and Memory Coherence for the Self: Linking Two Characteristics of Autobiographical Memory

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Elien Vanderveren

2017-12-01

Full Text Available Autobiographical memory forms a network of memories about personal experiences that defines and supports well-being and effective functioning of the self in various ways. During the last three decades, there have been two characteristics of autobiographical memory that have received special interest regarding their role in psychological well-being and psychopathology, namely memory specificity and memory coherence. Memory specificity refers to the extent to which retrieved autobiographical memories are specific (i.e., memories about a particular experience that happened on a particular day. Difficulty retrieving specific memories interferes with effective functioning of the self and is related to depression and post-traumatic stress disorder. Memory coherence refers to the narrative expression of the overall structure of autobiographical memories. It has likewise been related to psychological well-being and the occurrence of psychopathology. Research on memory specificity and memory coherence has developed as two largely independent research domains, even though they show much overlap. This raises some important theoretical questions. How do these two characteristics of autobiographical memory relate to each other, both theoretically and empirically? Additionally, how can the integration of these two facilitate our understanding of the importance of autobiographical memory for the self? In this article, we give a critical overview of memory specificity and memory coherence and their relation to the self. We link both features of autobiographical memory by describing some important similarities and by formulating hypotheses about how they might relate to each other. By situating both memory specificity and memory coherence within Conway and Pleydell-Pearce’s Self-Memory System, we make a first attempt at a theoretical integration. Finally, we suggest some new and exciting research possibilities and explain how both research fields could benefit

Comparison of serum prostate specific antigen levels and bone scintigraphy in patients with prostate carcinoma

International Nuclear Information System (INIS)

Bielickaite, J.; Zadeikaite, R.; Jurkiene, N. and others

2003-01-01

The aim of this study was to analyze the levels of serum prostate specific antigen in patients with and without bone metastases detected by means of bone scintigraphy and to determine the highest prostate specific antigen level in patients without bone metastases. The 50 patients consecutively diagnosed of prostate cancer between 1999 and 2001 in our institution made up the study population. Prostate specific antigen plasmatic levels were determined and bone scintigraphy was performed (whole body study after 99mTc-methyl-diphosphonate administration) in all the patients. In patients with positive bone scans (n=23), the mean prostate specific antigen level was 71.4±35.2 ng/ml and was significantly (p<0.00005) higher than in 14 patients with negative bone scans (mean prostate specific antigen level was 10.1±10.5 ng/ml). Suspicious lesions were found in 13 patients and their mean prostate specific antigen level was 8.5±7.7 ng/ml. Regarding prostate specific antigen levels, no statistically significant differences were found between patients with suspicious lessons and normal bone scans. The highest determined prostate specific antigen level in patients without bone metastases was 18 ng/ml. The bone scintigraphy should be performed in all patients with prostate specific antigen level above 18 ng/ml, but it is of limited value in patients with prostate specific antigen level below 18 ng/ml. (author)

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.

Loss of circulating CD4 T cells with B cell helper function during chronic HIV infection.

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Kristin L Boswell

2014-01-01

Full Text Available The interaction between follicular T helper cells (TFH and B cells in the lymph nodes and spleen has a major impact on the development of antigen-specific B cell responses during infection or vaccination. Recent studies described a functional equivalent of these cells among circulating CD4 T cells, referred to as peripheral TFH cells. Here, we characterize the phenotype and in vitro B cell helper activity of peripheral TFH populations, as well as the effect of HIV infection on these populations. In co-culture experiments we confirmed CXCR5+ cells from HIV-uninfected donors provide help to B cells and more specifically, we identified a CCR7(highCXCR5(highCCR6(highPD-1(high CD4 T cell population that secretes IL-21 and enhances isotype-switched immunoglobulin production. This population is significantly decreased in treatment-naïve, HIV-infected individuals and can be recovered after anti-retroviral therapy. We found impaired immunoglobulin production in co-cultures from HIV-infected individuals and found no correlation between the frequency of peripheral TFH cells and memory B cells, or with neutralization activity in untreated HIV infection in our cohort. Furthermore, we found that within the peripheral TFH population, the expression level of TFH-associated genes more closely resembles a memory, non-TFH population, as opposed to a TFH population. Overall, our data identify a heterogeneous population of circulating CD4 T cells that provides in vitro help to B cells, and challenges the origin of these cells as memory TFH cells.

Every breath you take: the impact of environment on resident memory CD8 T cells in the lung.

Science.gov (United States)

Shane, Hillary L; Klonowski, Kimberly D

2014-01-01

Resident memory T cells (TRM) are broadly defined as a population of T cells, which persist in non-lymphoid sites long-term, do not re-enter the circulation, and are distinct from central memory T cells (TCM) and circulating effector memory T cells (TEM). Recent studies have described populations of TRM cells in the skin, gut, lungs, and nervous tissue. However, it is becoming increasingly clear that the specific environment in which the TRM reside can further refine their phenotypical and functional properties. Here, we focus on the TRM cells that develop following respiratory infection and reside in the lungs and the lung airways. Specifically, we will review recent studies that have described some of the requirements for establishment of TRM cells in these tissues, and the defining characteristics of TRM in the lungs and lung airways. With continual bombardment of the respiratory tract by both pathogenic and environmental antigens, dynamic fluctuations in the local milieu including homeostatic resources and niche restrictions can impact TRM longevity. Beyond a comprehensive characterization of lung TRM cells, special attention will be placed on studies, which have defined how the microenvironment of the lung influences memory T cell survival at this site. As memory T cell populations in the lung airways are requisite for protection yet wane numerically over time, developing a comprehensive picture of factors which may influence TRM development and persistence at these sites is important for improving T cell-based vaccine design.

Every breath you take: The impact of environment on resident memory CD8 T cells in the lung

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Hillary eShane

2014-07-01

Full Text Available Resident memory T cells (TRM are broadly defined as a population of T cells which persist in non-lymphoid sites long term, do not re-enter the circulation, and are distinct from central memory T cells (TCM and circulating effector memory T cells (TEM. Recent studies have described populations of TRM cells in the skin, gut, lungs and nervous tissue. However, it is becoming increasingly clear that the specific environment in which the TRM reside can further refine their phenotypical and functional properties. Here, we focus on the TRM cells that develop following respiratory infection and reside in the lungs and the lung airways. Specifically, we will review recent studies that have described some of the requirements for establishment of TRM cells in these tissues, and the defining characteristics of TRM in the lungs and lung airways. With continual bombardment of the respiratory tract by both pathogenic and environmental antigens, dynamic fluctuations in the local milieu including homeostatic resources and niche restrictions can impact TRM longevity. Beyond a comprehensive characterization of lung TRM cells, special attention will be placed on studies which have defined how the microenvironment of the lung influences memory T cell survival at this site. As memory T cell populations in the lung airways are requisite for protection yet wane numerically over time, developing a comprehensive picture of factors which may influence TRM development and persistence at these sites is important for improving T cell-based vaccine design.

Distinction of the memory B cell response to cognate antigen versus bystander inflammatory signals.

Science.gov (United States)

Benson, Micah J; Elgueta, Raul; Schpero, William; Molloy, Michael; Zhang, Weijun; Usherwood, Edward; Noelle, Randolph J

2009-08-31

The hypothesis that bystander inflammatory signals promote memory B cell (B(MEM)) self-renewal and differentiation in an antigen-independent manner is critically evaluated herein. To comprehensively address this hypothesis, a detailed analysis is presented examining the response profiles of B-2 lineage B220(+)IgG(+) B(MEM) toward cognate protein antigen in comparison to bystander inflammatory signals. After in vivo antigen encounter, quiescent B(MEM) clonally expand. Surprisingly, proliferating B(MEM) do not acquire germinal center (GC) B cell markers before generating daughter B(MEM) and differentiating into plasma cells or form structurally identifiable GCs. In striking contrast to cognate antigen, inflammatory stimuli, including Toll-like receptor agonists or bystander T cell activation, fail to induce even low levels of B(MEM) proliferation or differentiation in vivo. Under the extreme conditions of adjuvanted protein vaccination or acute viral infection, no detectable bystander proliferation or differentiation of B(MEM) occurred. The absence of a B(MEM) response to nonspecific inflammatory signals clearly shows that B(MEM) proliferation and differentiation is a process tightly controlled by the availability of cognate antigen.

Immunodiagnosis of paracoccidioidomycosis due to Paracoccidioides brasiliensis using a latex test: detection of specific antibody anti-gp43 and specific antigen gp43.

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Priscila Oliveira Dos Santos

2015-02-01

Full Text Available Paracoccidioidomycosis (PCM is a life-threatening systemic disease and is a neglected public health problem in many endemic regions of Latin America. Though several diagnostic methods are available, almost all of them present with some limitations.A latex immunoassay using sensitized latex particles (SLPs with gp43 antigen, the immunodominant antigen of Paracoccidioides brasiliensis, or the monoclonal antibody mAb17c (anti-gp43 was evaluated for antibody or antigen detection in sera, cerebrospinal fluid (CSF, and bronchoalveolar lavage (BAL from patients with PCM due to P. brasiliensis. The gp43-SLPs performed optimally to detect specific antibodies with high levels of sensitivity (98.46%, 95% CI 91.7-100.0, specificity (93.94%, 95% CI 87.3-97.7, and positive (91.4% and negative (98.9% predictive values. In addition, we propose the use of mAb17c-SLPs to detect circulating gp43, which would be particularly important in patients with immune deficiencies who fail to produce normal levels of immunoglobulins, achieving good levels of sensitivity (96.92%, 95% CI 89.3-99.6, specificity (88.89%, 95% CI 81.0-94.3, and positive (85.1% and negative (97.8% predictive values. Very good agreement between latex tests and double immune diffusion was observed for gp43-SLPs (k = 0.924 and mAb17c-SLPs (k = 0.850, which reinforces the usefulness of our tests for the rapid diagnosis of PCM in less than 10 minutes. Minor cross-reactivity occurred with sera from patients with other fungal infections. We successfully detected antigens and antibodies from CSF and BAL samples. In addition, the latex test was useful for monitoring PCM patients receiving therapy.The high diagnostic accuracy, low cost, reduced assay time, and simplicity of this new latex test offer the potential to be commercialized and makes it an attractive diagnostic assay for use not only in clinics and medical mycology laboratories, but mainly in remote locations with limited laboratory infrastructure

Rapid production of antigen-specific monoclonal antibodies from a variety of animals

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Kurosawa Nobuyuki

2012-09-01

Full Text Available Abstract Background Although a variety of animals have been used to produce polyclonal antibodies against antigens, the production of antigen-specific monoclonal antibodies from animals remains challenging. Results We propose a simple and rapid strategy to produce monoclonal antibodies from a variety of animals. By staining lymph node cells with an antibody against immunoglobulin and a fluorescent dye specific for the endoplasmic reticulum, plasma/plasmablast cells were identified without using a series of antibodies against lineage markers. By using a fluorescently labeled antigen as a tag for a complementary cell surface immunoglobulin, antigen-specific plasma/plasmablast cells were sorted from the rest of the cell population by fluorescence-activated cell sorting. Amplification of cognate pairs of immunoglobulin heavy and light chain genes followed by DNA transfection into 293FT cells resulted in the highly efficient production of antigen-specific monoclonal antibodies from a variety of immunized animals. Conclusions Our technology eliminates the need for both cell propagation and screening processes, offering a significant advantage over hybridoma and display strategies.

Production of prostate-specific antigen by a breast cancer cell line, Sk-Br-3

International Nuclear Information System (INIS)

Kamali Sarvestani, E.; Ghaderi, A.

2002-01-01

Prostate-specific antigen is a 33-KDa serine protease that is produced predominantly by prostate epithelium. However, it has been shown that about 30-40% of female breast tumors produce prostate-specific antigen and its production is associated with the presence of estrogen and progesterone receptors. We have now developed a new tissue culture system to study prostate-specific antigen production in breast cancer and its association with prognostic factors such as progesterone receptor and c-erbB-2. For this purpose we investigated the ability of prostate-specific antigen production in five different cell lines, including two breast cancer cell lines, Sk-Br-3 and MDA-MB-453. The prostate-specific antigen in tissue culture supernatant and cytoplasm of the Sk-Br-3 cell line was detected by western blotting and immunoperoxidase, respectively. Furthermore, we found lower expression of c-erbB-2 in Sk-Br-3 than non-prostate-specific antigen producer breast cancer cell line, MDA-MB-453. Progesterone receptor was expressed by both prostate-specific antigen-positive and -negative cell lines and only the intensity of staining and the number of positive cells in Sk-Br-3 population was higher than MDA-MB-453. According to our findings prostate-specific antigen can be considered as a good prognostic factor in breast cancer and we suggest that these two cell lines are a good in vitro model to study the relationship of different breast cancer prognostic factors and their regulations

I-125 input into antibodies molecules specific to australian antigen

International Nuclear Information System (INIS)

Abdukayumov, A. M.; Chistyakov, P.G.; Garajshina, G. R.

1999-01-01

There are experimental data on I-125 input into antibodies molecules specific to superficial antigen of hepatitis B virus (australian antigen). Three ways of input are submitted: with the help of T chloramine usage, Bolton-Hunter Reagent and with the help of iodogen. There are also comparative characteristics of iodized products obtained: molar radioactivity, radiochemical frequency, immuno - reactivity. The report also discusses advantages and disadvantages of the used methods for inputting I-125 into antibodies to australian antigen in order to study the possibility of creating radio immunological test system for detecting superficial antigen of B hepatitis

Autobiographical memory specificity in dissociative identity disorder.

Science.gov (United States)

Huntjens, Rafaële J C; Wessel, Ineke; Hermans, Dirk; van Minnen, Agnes

2014-05-01

A lack of adequate access to autobiographical knowledge has been related to psychopathology. More specifically, patients suffering from depression or a history of trauma have been found to be characterized by overgeneral memory, in other words, they show a relative difficulty in retrieving a specific event from memory located in time and place. Previous studies of overgeneral memory have not included patients with dissociative disorders. These patients are interesting to consider, as they are hypothesized to have the ability to selectively compartmentalize information linked to negative emotions. This study examined avoidance and overgeneral memory in patients with dissociative identity disorder (DID; n = 12). The patients completed the autobiographical memory test (AMT). Their performance was compared with control groups of posttraumatic stress disorder (PTSD) patients (n = 26), healthy controls (n = 29), and DID simulators (n = 26). Specifically, we compared the performance of separate identity states in DID hypothesized to diverge in the use of avoidance as a coping strategy to deal with negative affect. No significant differences in memory specificity were found between the separate identities in DID. Irrespective of identity state, DID patients were characterized by a lack of memory specificity, which was similar to the lack of memory specificity found in PTSD patients. The converging results for DID and PTSD patients add empirical evidence for the role of overgeneral memory involved in the maintenance of posttraumatic psychopathology.

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

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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.

Specifically activated memory T cell subsets from cancer patients recognize and reject xenotransplanted autologous tumors

Science.gov (United States)

Beckhove, Philipp; Feuerer, Markus; Dolenc, Mathias; Schuetz, Florian; Choi, Carmen; Sommerfeldt, Nora; Schwendemann, Jochen; Ehlert, Katrin; Altevogt, Peter; Bastert, Gunther; Schirrmacher, Volker; Umansky, Viktor

2004-01-01

Bone marrow of breast cancer patients was found to contain CD8+ T cells specific for peptides derived from breast cancer–associated proteins MUC1 and Her-2/neu. Most of these cells had a central or effector memory phenotype (CD45RA–CD62L+ or CD45RA–CD62L–, respectively). To test their in vivo function, we separated bone marrow–derived CD45RA+ naive or CD45RA–CD45RO+ memory T cells, stimulated them with autologous dendritic cells pulsed with tumor lysate, and transferred them into NOD/SCID mice bearing autologous breast tumors and normal skin transplants. CD45RA– memory but not CD45RA+ naive T cells infiltrated autologous tumor but not skin tissues after the transfer. These tumor-infiltrating cells had a central or effector memory phenotype and produced perforin. Many of them expressed the P-selectin glycoprotein ligand 1 and were found around P-selectin+ tumor endothelium. Tumor infiltration included cluster formation in tumor tissue by memory T cells with cotransferred dendritic cells. It was associated with the induction of tumor cell apoptosis and significant tumor reduction. We thus demonstrate selective homing of memory T cells to human tumors and suggest that tumor rejection is based on the recognition of tumor-associated antigens on tumor cells and dendritic cells by autologous specifically activated central and effector memory T cells. PMID:15232613

Niches for the Long-Term Maintenance of Tissue-Resident Memory T Cells

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Takamura, Shiki

2018-01-01

Tissue-resident memory T cells (TRM cells) are a population of immune cells that reside in the lymphoid and non-lymphoid organs without recirculation through the blood. These important cells occupy and utilize unique anatomical and physiological niches that are distinct from those for other memory T cell populations, such as central memory T cells in the secondary lymphoid organs and effector memory T cells that circulate through the tissues. CD8+ TRM cells typically localize in the epithelial layers of barrier tissues where they are optimally positioned to act as sentinels to trigger antigen-specific protection against reinfection. CD4+ TRM cells typically localize below the epithelial layers, such as below the basement membrane, and cluster in lymphoid structures designed to optimize interactions with antigen-presenting cells upon reinfection. A key feature of TRM populations is their ability to be maintained in barrier tissues for prolonged periods of time. For example, skin CD8+ TRM cells displace epidermal niches originally occupied by γδ T cells, thereby enabling their stable persistence for years. It is also clear that the long-term maintenance of TRM cells in different microenvironments is dependent on multiple tissue-specific survival cues, although the specific details are poorly understood. However, not all TRM persist over the long term. Recently, we identified a new spatial niche for the maintenance of CD8+ TRM cells in the lung, which is created at the site of tissue regeneration after injury [termed repair-associated memory depots (RAMD)]. The short-lived nature of RAMD potentially explains the short lifespans of CD8+ TRM cells in this particular tissue. Clearly, a better understanding of the niche-dependent maintenance of TRM cells will be important for the development of vaccines designed to promote barrier immunity. In this review, we discuss recent advances in our understanding of the properties and nature of tissue-specific niches that

Fetal- and uterine-specific antigens in human amniotic fluid.

Science.gov (United States)

Sutcliffe, R G; Brock, D J; Nicholson, L V; Dunn, E

1978-09-01

Removal of the major maternal serum proteins from second trimester amniotic fluid by antibody affinity chromatography revealed various soluble tissue antigens, of which two were fetal-specific skin proteins and another, of alpha2-mobility, was specific to the uterus, and was therefore designated alpha-uterine protein (AUP). These proteins could not be detected in maternal serum by antibody-antigen crossed electrophoresis. The concentration of AUP in amniotic fluid reached a maximum between 10 and 20 weeks of gestation, suggesting that there is an influx of uterine protein into the amniotic fluid at this stage of pregnancy.

Erasing the Epigenetic Memory and Beginning to Switch—The Onset of Antigenic Switching of var Genes in Plasmodium falciparum

Science.gov (United States)

Fastman, Yair; Noble, Robert; Recker, Mario; Dzikowski, Ron

2012-01-01

Antigenic variation in Plasmodium falciparum is regulated by transcriptional switches among members of the var gene family, each expressed in a mutually exclusive manner and encoding a different variant of the surface antigens collectively named PfEMP1. Antigenic switching starts when the first merozoites egress from the liver and begin their asexual proliferation within red blood cells. By erasing the epigenetic memory we created parasites with no var background, similar to merozoites that egress from the liver where no var gene is expressed. Creating a null-var background enabled us to investigate the onset of antigenic switches at the early phase of infection. At the onset of switching, var transcription pattern is heterogeneous with numerous genes transcribed at low levels including upsA vars, a subtype that was implicated in severe malaria, which are rarely activated in growing cultures. Analysis of subsequent in vitro switches shows that the probability of a gene to turn on or off is not associated with its chromosomal position or promoter type per se but on intrinsic properties of each gene. We concluded that var switching is determined by gene specific associated switch rates rather than general promoter type or locus associated switch rates. In addition, we show that fine tuned reduction in var transcription increases their switch rate, indicating that transcriptional perturbation can alter antigenic switching. PMID:22461905

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

KAUST Repository

Domina, Maria; Lanza Cariccio, Veronica; Benfatto, Salvatore; D'Aliberti, Deborah; Venza, Mario; Borgogni, Erica; Castellino, Flora; Biondo, Carmelo; D'Andrea, Daniel; Grassi, Luigi; Tramontano, Anna; Teti, Giuseppe; Felici, Franco; Beninati, Concetta

2014-01-01

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

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

Directory of Open Access Journals (Sweden)

Maria Domina

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

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

KAUST Repository

Domina, Maria

2014-12-04

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

Schistosome circulating anodic antigen in serum of individuals infected with Schistosoma japonicum from the Philippines before and after chemotherapy with praziquantel

NARCIS (Netherlands)

van 't Wout, A. B.; de Jonge, N.; Tiu, W. U.; Garcia, E. E.; Mitchell, G. F.; Deelder, A. M.

1992-01-01

The presence of the schistosome circulating anodic antigen (CAA) in serum of patients infected with Schistosoma japonicum from The Philippines has been investigated using an enzyme-linked immunosorbent assay (ELISA). Serum samples were tested from 48 patients who excreted S. japonicum eggs, 9

Detection of the circulating antigen 14-3-3 protein of Schistosoma japonicum by time-resolved fluoroimmunoassay in rabbits

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Wang Jie

2011-05-01

Full Text Available Abstract Background Schistosomiasis remains a major public health concern that afflicts millions of people worldwide. Low levels of Schistosoma infection require more sensitive diagnostic methods. In this study, a time-resolved fluoroimmunoassay (TRFIA was developed for detecting the signal transduction protein 14-3-3, a circulating antigen of Schistosoma japonicum. Results The detection limit of 14-3-3-TRFIA was 0.78 ng/ml, with a linear measurement range from 0.78 to 800 ng/ml. The average intra-assay and inter-assay variability of this TRFIA was 8.9% and 12.2% respectively, and the mean recovery rate ranged from 92.1% to 115.5%. Within the first 21 days post-infection in rabbits, the positive rates of the 14-3-3-TRFIA were distinctly higher compared to ELISA. All these findings illustrate that 14-3-3-TRFIA has a higher detection efficacy and is a good early diagnostic method for active Schistosoma infection. Conclusions A sandwich TRFIA for detecting the circulating antigen 14-3-3 of S. japonicum has been developed, and has demonstrated to be a good potential diagnostic method for schistosomiasis.

Breadth of T cell responses after immunization with adenovirus vectors encoding ancestral antigens or polyvalent papillomavirus antigens

DEFF Research Database (Denmark)

Ragonnaud, Emeline; Pedersen, Anders Gorm; Holst, Peter Johannes

2017-01-01

to the other PV proteins. The PV sequences were fused to a T cell adjuvant, the murine invariant chain and encoded in a recombinant adenoviral vector which was administered to naïve outbred mice. By measuring T cell responses induced by these different vaccines and towards peptide pools representing 3...... circulating strains and a putative ancestor of oncogenic HPVs, we showed that the ancestral vaccine antigen has to be approximately 90% identical to the circulating PVs before a marked drop of ~90% mean CD8+ T cell responses ensues. Interestingly, the combination of two or three type-specific PV vaccines did...

Prostate specific antigen velocity does not aid prostate cancer detection in men with prior negative biopsy.

Science.gov (United States)

Vickers, Andrew J; Wolters, Tineke; Savage, Caroline J; Cronin, Angel M; O'Brien, M Frank; Roobol, Monique J; Aus, Gunnar; Scardino, Peter T; Hugosson, Jonas; Schröder, Fritz H; Lilja, Hans

2010-09-01

Prostate specific antigen velocity has been proposed as a marker to aid in prostate cancer detection. We determined whether prostate specific antigen velocity could predict repeat biopsy results in men with persistently increased prostate specific antigen after initial negative biopsy. We identified 1,837 men who participated in the Göteborg or Rotterdam section of the European Randomized Screening study of Prostate Cancer and who underwent 1 or more subsequent prostate biopsies after an initial negative finding. We evaluated whether prostate specific antigen velocity improved predictive accuracy beyond that of prostate specific antigen alone. Of the 2,579 repeat biopsies 363 (14%) were positive for prostate cancer, of which 44 (1.7%) were high grade (Gleason score 7 or greater). Prostate specific antigen velocity was statistically associated with cancer risk but had low predictive accuracy (AUC 0.55, p <0.001). There was some evidence that prostate specific antigen velocity improved AUC compared to prostate specific antigen for high grade cancer. However, the small increase in risk associated with high prostate specific antigen velocity (from 1.7% to 2.8% as velocity increased from 0 to 1 ng/ml per year) had questionable clinical relevance. Men with prior negative biopsy are at lower risk for prostate cancer at subsequent biopsies with high grade disease particularly rare. We found little evidence to support prostate specific antigen velocity to aid in decisions about repeat biopsy for prostate cancer. 2010 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Early appearance of germinal center–derived memory B cells and plasma cells in blood after primary immunization

Science.gov (United States)

Blink, Elizabeth J.; Light, Amanda; Kallies, Axel; Nutt, Stephen L.; Hodgkin, Philip D.; Tarlinton, David M.

2005-01-01

Immunization with a T cell–dependent antigen elicits production of specific memory B cells and antibody-secreting cells (ASCs). The kinetic and developmental relationships between these populations and the phenotypic forms they and their precursors may take remain unclear. Therefore, we examined the early stages of a primary immune response, focusing on the appearance of antigen-specific B cells in blood. Within 1 wk, antigen-specific B cells appear in the blood with either a memory phenotype or as immunoglobulin (Ig)G1 ASCs expressing blimp-1. The memory cells have mutated VH genes; respond to the chemokine CXCL13 but not CXCL12, suggesting recirculation to secondary lymphoid organs; uniformly express B220; show limited differentiation potential unless stimulated by antigen; and develop independently of blimp-1 expression. The antigen-specific IgG1 ASCs in blood show affinity maturation paralleling that of bone marrow ASCs, raising the possibility that this compartment is established directly by blood-borne ASCs. We find no evidence for a blimp-1–expressing preplasma memory compartment, suggesting germinal center output is restricted to ASCs and B220+ memory B cells, and this is sufficient to account for the process of affinity maturation. PMID:15710653

The specificity and organisation of autobiographical memories.

Science.gov (United States)

Schulkind, Matthew D; Rahhal, Tamara A; Klein, Megan R; Lacher, Samantha R

2012-01-01

Previous research suggests that autobiographical memories are over-general and are organised according to life periods. One experiment assessed the specificity and organisation of autobiographical memory by manipulating two variables. The retrieval cues were either a set of three words (a theme, a time period, and an emotional valence) or a short narrative that included a specific theme, time period, and emotional valence. The instructions either encouraged the participants to respond as though they were conversing with a friend (social instructions) or did not specify a target audience (standard instructions). Narrative cues and standard instructions elicited more specific responses than word cues and social instructions, respectively. Whereas word cues elicited memories that were most likely to match the cues in terms of time period, narrative cues elicited memories that were most likely to match the cues in terms of theme. These data suggest that previous research underestimated the specificity of the autobiographical knowledge base and overestimated the importance of temporally defined life periods for organising autobiographical memory. Previous conclusions regarding the specificity and organisation of autobiographical memory may reflect the structure of autobiographical narratives and the methodologies used to collect such narratives rather than the content of autobiographical memory itself.

Characterization of a human antigen specific helper factor

International Nuclear Information System (INIS)

Richardson, B.

1986-01-01

While antigen (Ag) specific helper factors have been characterized in mice, similar molecules have not been identified in humans. To characterize human antigen specific helper molecules, an IL-2 dependent tetanus toxoid (T.T.) reactive T cell line was fused with a 6-thioguanine resistant CEM line, and hybrids selected in medium containing hypoxanthine and azaserine. Hybrids were screened by culturing the cells with 35 S-Met then reacting the supernatants with T.T. or hepatitis vaccine immobilized on nitrocellulose. One hybrid, TT6BA-O, was identified which secreted a Met-containing molecule which bound T.T. but not hepatitis vaccine. Supernatants from TT6BA-O, but not the parent CEM line, when added to autologous peripheral blood mononuclear cells (PBMC's) stimulated secretion of T.T. specific antibodies (Abs). Specificity controls demonstrated that TT6BA-O supernatant did not induce antibodies to diphtheria toxoid, hepatitis vaccine or pneumococcal polysaccharide, and total immunoglobulin (lg) synthesis was minimally increased. In contrast, pokeweed mitogen stimulated significant lg synthesis as well as Ab's to pneumococcal polysaccharide and T.T. TT6BA-O supernatant induced anti-T.T.Ab's in autologous PBMC's but not PBMC's from 3 unrelated donors, suggesting that the activity of the helper factor is restricted, possibly by the MHC. The molecular weight of the helper factor was estimated at 100,000-150,000 by Sephacryl S-300 chromatography. Finally, the helper factor could be demonstrated to bind and elute from sephorose-immobilized T.T. and anti-DR antisera, but not anti-lg antisera or the T40/25 monoclonal antibody, which binds a nonpolymorphic determinant on the human T cell receptor. These results demonstrate that human Ag specific helper factors exist, bind antigen and bear class II MHC determinants

CD4 T-Cell Memory Generation and Maintenance

Science.gov (United States)

Gasper, David J.; Tejera, Melba Marie; Suresh, M.

2014-01-01

Immunologic memory is the adaptive immune system's powerful ability to remember a previous antigen encounter and react with accelerated vigor upon antigen re-exposure. It provides durable protection against reinfection with pathogens and is the foundation for vaccine-induced immunity. Unlike the relatively restricted immunologic purview of memory B cells and CD8 T cells, the field of CD4 T-cell memory must account for multiple distinct lineages with diverse effector functions, the issue of lineage commitment and plasticity, and the variable distribution of memory cells within each lineage. Here, we discuss the evidence for lineage-specific CD4 T-cell memory and summarize the known factors contributing to memory-cell generation, plasticity, and long-term maintenance. PMID:24940912

Specific binding of antigen-antibody in physiological environments: Measurement, force characteristics and analysis

Science.gov (United States)

Gu, Xin; Zhou, Jun; Zhou, Lu; Xie, Shusen; Petti, Lucia; Wang, Shaomin; Wang, Fuyan

2018-05-01

The specific recognition of the antigen by the antibody is the crucial step in immunoassays. Measurement and analysis of the specific recognition, including the ways in which it is influenced by external factors are of paramount significance for the quality of the immunoassays. Using prostate-specific antigen (PSA)/anti-PSA antibody and α-fetoprotein (AFP) /anti-AFP antibody as examples, we have proposed a novel solution for measuring the binding forces between the antigens and their corresponding antibodies in different physiological environments by combining laminar flow control technology and optical tweezers technology. On the basis of the experimental results, the different binding forces of PSA/anti-PSA antibody and AFP/anti-AFP antibody in the same phosphate-buffered saline (PBS) environments are analysed by comparing the affinity constant of the two antibodies and the number of antigenic determinants of the two antigens. In different electrolyte environments, the changes of the binding force of antigens-antibodies are explained by the polyelectrolyte effect and hydrophobic interaction. Furthermore, in different pH environments, the changes of binding forces of antigens-antibodies are attributed to the role of the denaturation of protein. The study aims to recognise the antigen-antibody immune mechanism, thus ensuring further understanding of the biological functions of tumour markers, and it promises to be very useful for the clinical diagnosis of early-stage cancer.

Prostate Specific Membrane Antigen (PSMA) Targeted Bio-orthogonal Therapy for Metastatic Prostate Cancer

Science.gov (United States)

2017-10-01

AWARD NUMBER: W81XWH-16-1-0595 TITLE: Prostate-Specific Membrane Antigen (PSMA) Targeted Bio -orthogonal Therapy for Metastatic Prostate Cancer...Sep 2016 - 14 Sep 2017 4. TITLE AND SUBTITLE Prostate-Specific Membrane Antigen (PSMA) Targeted Bio -orthogonal Therapy for Metastatic Prostate

Prostate-specific antigen-based prostate cancer screening: Past and future.

Science.gov (United States)

Alberts, Arnout R; Schoots, Ivo G; Roobol, Monique J

2015-06-01

Prostate-specific antigen-based prostate cancer screening remains a controversial topic. Up to now, there is worldwide consensus on the statement that the harms of population-based screening, mainly as a result of overdiagnosis (the detection of clinically insignificant tumors that would have never caused any symptoms), outweigh the benefits. However, worldwide opportunistic screening takes place on a wide scale. The European Randomized Study of Screening for Prostate Cancer showed a reduction in prostate cancer mortality through prostate-specific antigen based-screening. These population-based data need to be individualized in order to avoid screening in those who cannot benefit and start screening in those who will. For now, lacking a more optimal screening approach, screening should only be started after the process of shared decision-making. The focus of future research is the reduction of unnecessary testing and overdiagnosis by further research to better biomarkers and the value of the multiparametric magnetic resonance imaging, potentially combined in already existing prostate-specific antigen-based multivariate risk prediction models. © 2015 The Japanese Urological Association.

Association of Neisseria gonorrhoeae Opa(CEA with dendritic cells suppresses their ability to elicit an HIV-1-specific T cell memory response.

Directory of Open Access Journals (Sweden)

Qigui Yu

Full Text Available Infection with Neisseria gonorrhoeae (N. gonorrhoeae can trigger an intense local inflammatory response at the site of infection, yet there is little specific immune response or development of immune memory. Gonococcal surface epitopes are known to undergo antigenic variation; however, this is unlikely to explain the weak immune response to infection since individuals can be re-infected by the same serotype. Previous studies have demonstrated that the colony opacity-associated (Opa proteins on the N. gonorrhoeae surface can bind human carcinoembryonic antigen-related cellular adhesion molecule 1 (CEACAM1 on CD4⁺ T cells to suppress T cell activation and proliferation. Interesting in this regard, N. gonorrhoeae infection is associated with impaired HIV-1 (human immunodeficiency virus type 1-specific cytotoxic T-lymphocyte (CTL responses and with transient increases in plasma viremia in HIV-1-infected patients, suggesting that N. gonorrhoeae may also subvert immune responses to co-pathogens. Since dendritic cells (DCs are professional antigen presenting cells (APCs that play a key role in the induction of an adaptive immune response, we investigated the effects of N. gonorrhoeae Opa proteins on human DC activation and function. While morphological changes reminiscent of DC maturation were evident upon N. gonorrhoeae infection, we observed a marked downregulation of DC maturation marker CD83 when the gonococci expressing CEACAM1-specific Opa(CEA, but not other Opa variants. Consistent with a gonococcal-induced defect in maturation, Opa(CEA binding to CEACAM1 reduced the DCs' capacity to stimulate an allogeneic T cell proliferative response. Moreover, Opa(CEA-expressing N. gonorrhoeae showed the potential to impair DC-dependent development of specific adaptive immunity, since infection with Opa(CEA-positive gonococci suppressed the ability of DCs to stimulate HIV-1-specific memory CTL responses. These results reveal a novel mechanism to explain

Hardware Compilation of Application-Specific Memory-Access Interconnect

DEFF Research Database (Denmark)

Venkataramani, Girish; Bjerregaard, Tobias; Chelcea, Tiberiu

2006-01-01

operations dependent on memory reads. More fundamental is that dependences between accesses may not be statically provable (e.g., if the specification language permits pointers), which introduces memory-consistency problems. Addressing these issues with static scheduling results in overly conservative...... enables specifications to include arbitrary memory references (e.g., pointers) and allows the memory system to incorporate features that might cause the latency of a memory access to vary dynamically. This results in raising the level of abstraction in the input specification, enabling faster design times...

CELLISA: reporter cell-based immunization and screening of hybridomas specific for cell surface antigens.

Science.gov (United States)

Chen, Peter; Mesci, Aruz; Carlyle, James R

2011-01-01

Monoclonal antibodies (mAbs) specific for cell surface antigens are an invaluable tool to study immune receptor expression and function. Here, we outline a generalized reporter cell-based approach to the generation and high-throughput screening of mAbs specific for cell surface antigens. Termed CELLISA, this technology hinges upon the capture of hybridoma supernatants in mAb arrays that facilitate ligation of an antigen of interest displayed on BWZ reporter cells in the form of a CD3ζ-fusion chimeric antigen receptor (zCAR); in turn, specific mAb-mediated cross-linking of zCAR on BWZ cells results in the production of β-galactosidase enzyme (β-gal), which can be assayed colorimetrically. Importantly, the BWZ reporter cells bearing the zCAR of interest may be used for immunization as well as screening. In addition, serial immunizations employing additional zCAR- or native antigen-bearing cell lines can be used to increase the frequency of the desired antigen-specific hybridomas. Finally, the use of a cohort of epitope-tagged zCAR (e.g., zCAR(FLAG)) variants allows visualization of the cell surface antigen prior to immunization, and coimmunization using these variants can be used to enhance the immunogenicity of the target antigen. Employing the CELLISA strategy, we herein describe the generation of mAb directed against an uncharacterized natural killer cell receptor protein.

CCR6-dependent positioning of memory B cells is essential for their ability to mount a recall response to antigen

Science.gov (United States)

Elgueta, Raul; Marks, Ellen; Nowak, Elizabeth; Menezes, Shinelle; Benson, Micah; Raman, Vanitha S.; Ortiz, Carla; O’Connell, Samuel; Hess, Henry; Lord, Graham M.; Noelle, Randolph

2014-01-01

Chemokine-dependent localization of specific B cell subsets within the immune microarchitecture is essential to insure successful cognate interactions. While cognate interactions between T cells and memory B cells (Bmem)5 are essential for the secondary humoral immune responses, the chemokine response patterns of Bmem cells are largely unknown. In contrast to naïve B cells, this study shows that antigen-specific Bmem cells have heightened expression of CCR6 and a selective chemotactic response to the CCR6 ligand, CCL20. While CCR6 appears be non-essential for the initial clonal expansion and maintenance of Bmem, CCR6 is essential for the ability of Bmem to respond to a recall response to their cognate antigen. This dependency was deemed intrinsic by studies in CCR6-deficient mice and in bone-marrow chimeric mice where CCR6 deficiency was limited to the B cell lineage. Finally, the mis-positioning of CCR6-deficient Bmem was revealed by immunohistological analysis with an altered distribution of CCR6-deficient Bmem from the marginal and perifollicular to the follicular/germinal center area. PMID:25505290

Plasmablasts During Acute Dengue Infection Represent a Small Subset of a Broader Virus-specific Memory B Cell Pool

Directory of Open Access Journals (Sweden)

Ramapraba Appanna

2016-10-01

Full Text Available Dengue is endemic in tropical countries worldwide and the four dengue virus serotypes often co-circulate. Infection with one serotype results in high titers of cross-reactive antibodies produced by plasmablasts, protecting temporarily against all serotypes, but impairing protective immunity in subsequent infections. To understand the development of these plasmablasts, we analyzed virus-specific B cell properties in patients during acute disease and at convalescence. Plasmablasts were unrelated to classical memory cells expanding in the blood during early recovery. We propose that only a small subset of memory B cells is activated as plasmablasts during repeat infection and that plasmablast responses are not representative of the memory B cell repertoire after dengue infection.

Splenic B cells and antigen-specific B cells process anti-Ig in a similar manner

International Nuclear Information System (INIS)

Myers, C.D.; Vitetta, E.S.

1989-01-01

B lymphocytes can process and present antigen to T cells. However, the fate of native antigen after its binding to specific B cells, i.e., the intracellular events involved in the processing and recycling of the antigenic fragments to the cell surface for antigen presentation, are not well understood. In the present study, we demonstrate that murine B cells degrade anti-Ig molecules bound to their surface and release acid soluble fragments into the supernatant. We also demonstrate that the kinetics of this process are identical for anti-mu, anti-delta, and anti-light chain antibodies, indicating that both surface IgM and surface IgD are equally effective in binding antigen and directing its processing. We also describe the effects of azide, chloroquine, and irradiation on this process. To extend these studies to the processing of specifically bound antigen, we demonstrate that highly purified trinitrophenyl antigen-binding cells degrade anti-Ig molecules with the same kinetics as unpurified splenic B cells. Thus, this purified population provides a suitable model system for the analysis of antigen degradation by antigen-specific cells

Enhanced specificity in immunoscreening of expression cDNA clones using radiolabeled antigen overlay

International Nuclear Information System (INIS)

Chao, S.; Chao, L.; Chao, J.

1989-01-01

A highly sensitive and specific method has been developed for immunoscreening clones from an expression cDNA library. The procedures utilize a radiolabeled antigen detection method described originally for the immunoblotting of plasma proteins. Screening of rat alpha 1-antitrypsin clones was used. Comparison between Western blots of alpha 1-antitrypsin using both labeled antigen and protein A detection methods showed that the former yielded lower background and greater sensitivity than the latter. Further, this technique was shown to have a lower detection limit of less than 20 ng through Western blot analysis of varying concentrations of alpha 1-antitrypsin. The procedures are based on the expression of the protein by cDNA clones containing the DNA inserts in the correct reading frame. Following the transfer of phage proteins to nitrocellulose membranes, the bivalent antibodies bind monovalently to both nitrocellulose-bound-antigen in the phage lysates and radiolabeled antigen. The radiolabeled antigen overlay method is superior to the protein A detection method in sensitivity, specificity and reproducibility. This improved method can be applied in general for screening expression cDNA libraries, provided that the specific antiserum and radiolabeled antigen are available

Docking of B-cell epitope antigen to specific hepatitis B antibody

Indian Academy of Sciences (India)

The interaction of pres1 region of hepatitis B virus B-cell epitope antigen with specific hepatitis B neutralizing monoclonal antibody was examined by docking study. We modelled the 3D complex structure of B-cell epitope antigen residues CTTPAQGNSMFPSCCCTKPTDGNCY by homology modelling and docked it with the ...

Immunizations with hepatitis B viral antigens and a TLR7/8 agonist adjuvant induce antigen-specific immune responses in HBV-transgenic mice

Directory of Open Access Journals (Sweden)

Ying Wang

2014-12-01

Conclusions: Immunization with CL097-conjugated HBV-Ag reversed immune tolerance in HBV-Tg mice and induced antigen-specific immune responses. TLR7/8 agonists appear to be potent adjuvants for the induction of antigen-specific Th1 responses in an immune tolerant state.

Use of a solid-phase radioimmunoassay and formalin-fixed whole bacterial antigen in the detection of antigen-specific immunoglobulin in prostatic fluid.

OpenAIRE

Shortliffe, L M; Wehner, N; Stamey, T A

1981-01-01

The prostatic fluid of two patients with Escherichia coli bacterial prostatitis was analyzed for evidence of a local immune response to bacterial infection. A solid-phase radioimmunoassay was modified to measure the immunoglobulin (Ig)A and IgG antigen-specific antibody responses to infecting bacteria in serum and prostatic fluid from patient. Formalin-fixed whole E. coli were used as antigen. In one patient with acute E. coli prostatic infection, measurements of antigen-specific antibody con...

Identifying long-term memory B-cells in vaccinated children despite waning antibody levels specific for Bordetella pertussis proteins.

Science.gov (United States)

Hendrikx, Lotte H; Oztürk, Kemal; de Rond, Lia G H; Veenhoven, Reinier H; Sanders, Elisabeth A M; Berbers, Guy A M; Buisman, Anne-Marie

2011-02-04

Whooping cough is a respiratory disease caused by Bordetella pertussis. Since the 1950s in developed countries pertussis vaccinations are included in the national immunization program. However, antibody levels rapidly wane after both whole cell and acellular pertussis vaccination. Therefore protection against pertussis may depend largely on long-term B- and T-cell immunities. We investigated long-term pertussis-specific memory B-cell responses in children who were primed at infant age with the Dutch wP-vaccine (ISRCTN65428640). Purified B-cells were characterized by FACS-analysis and after polyclonal stimulation memory B-cells were detected by ELISPOT-assays specific for pertussis toxin, filamentous haemagglutinin, pertactin and tetanus. In addition, plasma IgG levels directed to the same antigens were measured by a fluorescent bead-based multiplex immunoassay. Two and 3 years after wP priming as well as 2 and 5 years after the aP booster at the age of 4, low plasma IgG levels to the pertussis proteins were found. At the same time, however pertussis protein-specific memory B-cells could be detected and their number increased with age. The number of tetanus-specific memory B-cells was similar in all age groups, whereas IgG-tetanus levels were high 2 years after tetanus booster compared to pre- and 5 years post-booster levels. This study shows the presence of long-term pertussis protein-specific memory B-cells in children despite waning antibody levels after vaccination, which suggests that memory B-cells in addition to antibodies may contribute to protection against pertussis. Copyright © 2010 Elsevier Ltd. All rights reserved.

Routine detection of Epstein-Barr virus specific T-cells in the peripheral blood by flow cytometry

Science.gov (United States)

Crucian, B. E.; Stowe, R. P.; Pierson, D. L.; Sams, C. F.

2001-01-01

The ability to detect cytomegalovirus-specific T-cells (CD4(+)) in the peripheral blood by flow cytometry has been recently described by Picker et al. In this method, cells are incubated with viral antigen and responding (cytokine producing) T-cells are then identified by flow cytometry. To date, this technique has not been reliably used to detect Epstein-Barr virus (EBV)-specific T-cells primarily due to the superantigen/mitogenic properties of the virus which non-specifically activate T-cells. By modifying culture conditions under which the antigens are presented, we have overcome this limitation and developed an assay to detect and quantitate EBV-specific T-cells. The detection of cytokine producing T-cells by flow cytometry requires an extremely strong signal (such as culture in the presence of PMA and ionomycin). Our data indicate that in modified culture conditions (early removal of viral antigen) the non-specific activation of T-cells by EBV is reduced, but antigen presentation will continue uninhibited. Using this method, EBV-specific T-cells may be legitimately detected using flow cytometry. No reduction in the numbers of antigen-specific T-cells was observed by the early removal of target antigen when verified using cytomegalovirus antigen (a virus with no non-specific T-cell activation properties). In EBV-seropositive individuals, the phenotype of the EBV-specific cytokine producing T-cells was evaluated using four-color flow cytometry and found to be CD45(+), CD3(+), CD4(+), CD45RA(-), CD69(+), CD25(-). This phenotype indicates the stimulation of circulating previously unactivated memory T-cells. No cytokine production was observed in CD4(+) T-cells from EBV-seronegative individuals, confirming the specificity of this assay. In addition, the use of four color cytometry (CD45, CD3, CD69, IFNgamma/IL-2) allows the total quantitative assessment of EBV-specific T-cells while monitoring the interference of EBV non-specific mitogenic activity. This method may

Antigenic specificity of serum antibodies in mice fed soy protein

DEFF Research Database (Denmark)

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

2003-01-01

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

Prostate specific antigen in the diagnosis and treatment of adenocarcinoma of the prostate. III. Radiation treated patients

International Nuclear Information System (INIS)

Stamey, T.A.; Kabalin, J.N.; Ferrari, M.

1989-01-01

Serum prostate specific antigen was determined (Yang polyclonal radioimmunoassay) in 183 men after radiation therapy for adenocarcinoma of the prostate. A total of 163 men had received 7,000 rad external beam radiotherapy and 20 had been implanted with iodine-125 seeds. Only 11 per cent of these 183 patients had undetectable prostate specific antigen levels at a mean interval of 5 years since completion of radiotherapy. Prostate specific antigen levels after radiotherapy were directly related to initial clinical stage and Gleason score before treatment. Multiple prostate specific antigen determinations were performed with time in 124 of 183 patients. During year 1 after radiotherapy prostate specific antigen levels were decreasing in 82 per cent of the patients but only 8 per cent continued to decrease beyond year 1. Of 80 patients observed greater than 1 year after completion of radiotherapy 51 per cent had increasing values and 41 per cent had stable values. Increasing prostate specific antigen values after radiotherapy were correlated with progression to metastastic disease and residual cancer on prostate biopsy. Total serum acid phosphatase levels were poorly related to prostate specific antigen levels, were less effective in discriminating patients with metastatic disease and provided no additional information beyond that provided by prostate specific antigen

REMODELING SENSORY CORTICAL MAPS IMPLANTS SPECIFIC BEHAVIORAL MEMORY

Science.gov (United States)

Bieszczad, Kasia M.; Miasnikov, Alexandre A.; Weinberger, Norman M.

2013-01-01

Neural mechanisms underlying the capacity of memory to be rich with sensory detail are largely unknown. A candidate mechanism is learning-induced plasticity that remodels adult sensory cortex. Here, expansion in the primary auditory cortical (A1) tonotopic map of rats was induced by pairing a 3.66 kHz tone with activation of the nucleus basalis, mimicking the effects of natural associative learning. Remodeling of A1 produced de novo specific behavioral memory, but neither memory nor plasticity were consistently at the frequency of the paired tone, which typically decreased in A1 representation. Rather, there was a specific match between individual subjects’ area of expansion and the tone that was strongest in each animal’s memory, as determined by post-training frequency generalization gradients. These findings provide the first demonstration of a match between the artificial induction of specific neural representational plasticity and artificial induction of behavioral memory. As such, together with prior and present findings for detection, correlation and mimicry of plasticity with the acquisition of memory, they satisfy a key criterion for neural substrates of memory. This demonstrates that directly remodeling sensory cortical maps is sufficient for the specificity of memory formation. PMID:23639876

Synthesis and conjugation of oligosaccharide fragments related to the immunologically reactive part of the circulating anodic antigen of the parasite Schistosoma mansoni

NARCIS (Netherlands)

Vliegenthart, J.F.G.; Vermeer, H.J.; Halkes, K.M.; Kuik, J.A. van; Kamerling, J.P.

2000-01-01

The immunoreactive part of the circulating anodic antigen (CAA) from the parasite Schistosoma mansoni is a threonine-linked polysaccharide consisting of ->6)-[beta-D-GlcpA-(1->3)]-beta-D-GalpNAc-(1-> repeating disaccharides. In the framework of an immunochemical project, as a follow-up of earlier

Conventional CD4+ T cells present bacterial antigens to induce cytotoxic and memory CD8+ T cell responses.

Science.gov (United States)

Cruz-Adalia, Aránzazu; Ramirez-Santiago, Guillermo; Osuna-Pérez, Jesús; Torres-Torresano, Mónica; Zorita, Virgina; Martínez-Riaño, Ana; Boccasavia, Viola; Borroto, Aldo; Martínez Del Hoyo, Gloria; González-Granado, José María; Alarcón, Balbino; Sánchez-Madrid, Francisco; Veiga, Esteban

2017-11-17

Bacterial phagocytosis and antigen cross-presentation to activate CD8 + T cells are principal functions of professional antigen presenting cells. However, conventional CD4 + T cells also capture and kill bacteria from infected dendritic cells in a process termed transphagocytosis (also known as transinfection). Here, we show that transphagocytic T cells present bacterial antigens to naive CD8 + T cells, which proliferate and become cytotoxic in response. CD4 + T-cell-mediated antigen presentation also occurs in vivo in the course of infection, and induces the generation of central memory CD8 + T cells with low PD-1 expression. Moreover, transphagocytic CD4 + T cells induce protective anti-tumour immune responses by priming CD8 + T cells, highlighting the potential of CD4 + T cells as a tool for cancer immunotherapy.

Understanding original antigenic sin in influenza with a dynamical system.

Science.gov (United States)

Pan, Keyao

2011-01-01

Original antigenic sin is the phenomenon in which prior exposure to an antigen leads to a subsequent suboptimal immune response to a related antigen. Immune memory normally allows for an improved and rapid response to antigens previously seen and is the mechanism by which vaccination works. I here develop a dynamical system model of the mechanism of original antigenic sin in influenza, clarifying and explaining the detailed spin-glass treatment of original antigenic sin. The dynamical system describes the viral load, the quantities of healthy and infected epithelial cells, the concentrations of naïve and memory antibodies, and the affinities of naïve and memory antibodies. I give explicit correspondences between the microscopic variables of the spin-glass model and those of the present dynamical system model. The dynamical system model reproduces the phenomenon of original antigenic sin and describes how a competition between different types of B cells compromises the overall effect of immune response. I illustrate the competition between the naïve and the memory antibodies as a function of the antigenic distance between the initial and subsequent antigens. The suboptimal immune response caused by original antigenic sin is observed when the host is exposed to an antigen which has intermediate antigenic distance to a second antigen previously recognized by the host's immune system.

The CD8+ memory T-cell state of readiness is actively maintained and reversible

OpenAIRE

Allam, Atef; Conze, Dietrich B.; Giardino Torchia, Maria Letizia; Munitic, Ivana; Yagita, Hideo; Sowell, Ryan T.; Marzo, Amanda L.; Ashwell, Jonathan D.

2009-01-01

The ability of the adaptive immune system to respond rapidly and robustly upon repeated antigen exposure is known as immunologic memory, and it is thought that acquisition of memory T-cell function is an irreversible differentiation event. In this study, we report that many phenotypic and functional characteristics of antigen-specific CD8 memory T cells are lost when they are deprived of contact with dendritic cells. Under these circumstances, memory T cells reverted from G1 to the G0 cell-cy...

Specificity and detail in autobiographical memory: Same or different constructs?

Science.gov (United States)

Kyung, Yoonhee; Yanes-Lukin, Paula; Roberts, John E

2016-01-01

Research on autobiographical memory has focused on whether memories are coded as specific (i.e., describe a single event that happened at a particular time and place). Although some theory and research suggests that the amount of detail in autobiographical memories reflects a similar underlying construct as memory specificity, past research has not investigated whether these variables converge. Therefore, the present study compared the proportion of specific memories and the amount of detail embedded in memory responses to cue words. Results demonstrated that memory detail and proportion of specific memories were not correlated with each other and showed different patterns of association with other conceptually relevant variables. When responses to neutral cue words were examined in multiple linear and logistic regression analyses, the proportion of specific memories uniquely predicted less depressive symptoms, low emotional avoidance, lower emotion reactivity, better executive control and lower rumination, whereas the amount of memory detail uniquely predicted the presence of depression diagnosis, as well as greater depressive symptoms, subjective stress, emotion reactivity and rumination. Findings suggest that the ability to retrieve specific memories and the tendency to retrieve detailed personal memories reflect different constructs that have different implications in the development of emotional distress.

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

Remodeling sensory cortical maps implants specific behavioral memory.

Science.gov (United States)

Bieszczad, K M; Miasnikov, A A; Weinberger, N M

2013-08-29

Neural mechanisms underlying the capacity of memory to be rich in sensory detail are largely unknown. A candidate mechanism is learning-induced plasticity that remodels the adult sensory cortex. Here, expansion in the primary auditory cortical (A1) tonotopic map of rats was induced by pairing a 3.66-kHz tone with activation of the nucleus basalis, mimicking the effects of natural associative learning. Remodeling of A1 produced de novo specific behavioral memory, but neither memory nor plasticity was consistently at the frequency of the paired tone, which typically decreased in A1 representation. Rather, there was a specific match between individual subjects' area of expansion and the tone that was strongest in each animal's memory, as determined by post-training frequency generalization gradients. These findings provide the first demonstration of a match between the artificial induction of specific neural representational plasticity and artificial induction of behavioral memory. As such, together with prior and present findings for detection, correlation and mimicry of plasticity with the acquisition of memory, they satisfy a key criterion for neural substrates of memory. This demonstrates that directly remodeling sensory cortical maps is sufficient for the specificity of memory formation. Copyright © 2013 IBRO. Published by Elsevier Ltd. All rights reserved.

Developing antigen-specific therapies in multiple sclerosis: a tale of Tantalus or Ulysses?

Science.gov (United States)

van Noort JM

1999-10-01

Autoreactive T-cell responses directed to myelin proteins in the central nervous system are widely believed to be crucial in the pathology of multiple sclerosis (MS). However, effective ways of selectively targeting these T-cells in order to alter the clinical course of MS in a predictable manner has yet to be demonstrated. This review discusses two recent developments of crucial importance to the rational development of antigen-specific therapy in MS. The very idea of antigen-specific therapy in MS has long faced the challenge of determinant spreading, i.e., the development of novel autoimmune responses as the consequence of tissue damage. This phenomenon has led many to expect that in ongoing MS, many different pathogenic specificities would accumulate. Obviously, this would render antigen-specific therapy very difficult. Recent data now suggest that determinant spreading is most likely to be a transient phenomenon limited only to the first stages of tissue damage. A second development has changed our perspective on the specificity of individual T-cells and, thus, on the suitability of various ways to implement antigen-specific therapy. Evidence is rapidly accumulating that T-cell receptors are much more cross-reactive than previously assumed. This notion poses unexpected challenges to therapeutic approaches in MS that are based on selective targeting of autoreactive TCR. Vaccination with TCR peptides, administration of anti-TCR antibodies and development of therapeutically altered peptide ligands all depend on a significant level of predictability of pathogenic TCR. With such predictability now turning out to be much lower than was previously hoped, selective TCR-directed strategies for intervention may therefore turn out to be much less effective than anticipated. In the development of antigen-specific therapies, the use of whole protein tolerogens now seems to be the most promising route. Oral, intranasal or iv. administration of antigen remain viable options

Potent and Selective Peptidyl Boronic Acid Inhibitors of the Serine Protease Prostate-Specific Antigen

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LeBeau, Aaron M.; Singh, Pratap; Isaacs, John T.; Denmeade, Samuel R.

2012-01-01

SUMMARY Prostate cancer cells produce high (microgram to milligram/milliliter) levels of the serine protease Prostate-Specific Antigen (PSA). PSA is enzymatically active in the extracellular fluid surrounding prostate cancers but is found at 1,000- to 10,000-fold lower concentrations in the circulation, where it is inactivated due to binding to abundant serum protease inhibitors. The exclusive presence of high levels of active PSA within prostate cancer sites makes PSA an attractive candidate for targeted imaging and therapeutics. A synthetic approach based on a peptide substrate identified first peptide aldehyde and then boronic acid inhibitors of PSA. The best of these had the sequence Cbz-Ser-Ser-Lys-Leu-(boro)Leu, with a Ki for PSA of 65 nM. The inhibitor had a 60-fold higher Ki for chymotrypsin. A validated model of PSA’s catalytic site confirmed the critical interactions between the inhibitor and residues within the PSA enzyme. PMID:18635003

The Vast Universe of T Cell Diversity: Subsets of Memory Cells and Their Differentiation.

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Jandus, Camilla; Usatorre, Amaia Martínez; Viganò, Selena; Zhang, Lianjun; Romero, Pedro

2017-01-01

The T cell receptor confers specificity for antigen recognition to T cells. By the first encounter with the cognate antigen, reactive T cells initiate a program of expansion and differentiation that will define not only the ultimate quantity of specific cells that will be generated, but more importantly their quality and functional heterogeneity. Recent achievements using mouse model infection systems have helped to shed light into the complex network of factors that dictate and sustain memory T cell differentiation, ranging from antigen load, TCR signal strength, metabolic fitness, transcriptional programs, and proliferative potential. The different models of memory T cell differentiation are discussed in this chapter, and key phenotypic and functional attributes of memory T cell subsets are presented, both for mouse and human cells. Therapeutic manipulation of memory T cell generation is expected to provide novel unique ways to optimize current immunotherapies, both in infection and cancer.

Autobiographical Memory Specificity among Preschool-Aged Children

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Nuttall, Amy K.; Valentino, Kristin; Comas, Michelle; McNeill, Anne T.; Stey, Paul C.

2014-01-01

"Overgeneral memory" refers to difficulty retrieving specific autobiographical memories and is consistently associated with depression and/or trauma. The present study developed a downward extension of the Autobiographical Memory Test (AMT; Williams & Broadbent, 1986) given the need to document normative developmental changes in…

Antigen-specific immature dendritic cell vaccine ameliorates anti-dsDNA antibody-induced renal damage in a mouse model.

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Xia, Yumin; Jiang, Shan; Weng, Shenhong; Lv, Xiaochun; Cheng, Hong; Fang, Chunhong

2011-12-01

Dendritic cells (DCs) can inhibit immune response by clonal anergy when immature. Recent studies have shown that immature DCs (iDCs) may serve as a live cell vaccine after specific antigen pulse based on its potential of blocking antibody production. In this study, we aimed to investigate the effects of nuclear antigen-pulsed iDCs in the treatment of lupus-like renal damages induced by anti-dsDNA antibodies. iDCs were generated from haemopoietic stem cells in bone marrow and then pulsed in vitro with nuclear antigen. The iDC vaccine and corresponding controls were injected into mice with lupus-like renal damages. The evaluation of disease was monitored by biochemical parameters and histological scores. Anti-dsDNA antibody isotypes and T-lymphocyte-produced cytokines were analysed for elucidating therapeutic mechanisms. RESULTS; The mice treated with antigen-pulsed iDCs had a sustained remission of renal damage compared with those injected with non-pulsed iDCs or other controls, including decreased anti-dsDNA antibody level, less proteinuria, lower blood urea nitrogen and serum creatinine values, and improved histological evaluation. Analysis on isotypes of anti-dsDNA antibody showed that iDC vaccine preferentially inhibited the production of IgG3, IgG2b and IgG2a. Furthermore, administration of antigen-treated iDCs to mice resulted in significantly reduced IL-2, IL-4 and IL-12 and IFN-γ produced by T-memory cells. Conversely, the vaccination of antigen-pulsed mature DCs led to increased anti-dsDNA antibody production and an aggravation of lupus-like disease in the model. CONCLUSIONS; These results suggested the high potency of iDC vaccine in preventing lupus-like renal injuries induced by pathogenic autoantibodies.

A Latent Markov Modelling approach to the evaluation of Circulating Cathodic Antigen strips for Schistosomiasis diagnosis pre- and post-praziquantel treatment in Uganda

DEFF Research Database (Denmark)

Koukounari, Artemis; Donnelly, Christl A.; Moustaki, Irini

2013-01-01

Markov Models (LMMs). The aim was to evaluate the diagnostic accuracy of Circulating Cathodic Antigen (CCA) and of double Kato-Katz (KK) faecal slides over three consecutive days for Schistosoma mansoni infection simultaneously by age group at baseline and at two follow-up times post treatment...

Chimeric antigen receptor (CAR-specific monoclonal antibody to detect CD19-specific T cells in clinical trials.

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Bipulendu Jena

Full Text Available Clinical trials targeting CD19 on B-cell malignancies are underway with encouraging anti-tumor responses. Most infuse T cells genetically modified to express a chimeric antigen receptor (CAR with specificity derived from the scFv region of a CD19-specific mouse monoclonal antibody (mAb, clone FMC63. We describe a novel anti-idiotype monoclonal antibody (mAb to detect CD19-specific CAR(+ T cells before and after their adoptive transfer. This mouse mAb was generated by immunizing with a cellular vaccine expressing the antigen-recognition domain of FMC63. The specificity of the mAb (clone no. 136.20.1 was confined to the scFv region of the CAR as validated by inhibiting CAR-dependent lysis of CD19(+ tumor targets. This clone can be used to detect CD19-specific CAR(+ T cells in peripheral blood mononuclear cells at a sensitivity of 1∶1,000. In clinical settings the mAb is used to inform on the immunophenotype and persistence of administered CD19-specific T cells. Thus, our CD19-specific CAR mAb (clone no. 136.20.1 will be useful to investigators implementing CD19-specific CAR(+ T cells to treat B-lineage malignancies. The methodology described to develop a CAR-specific anti-idiotypic mAb could be extended to other gene therapy trials targeting different tumor associated antigens in the context of CAR-based adoptive T-cell therapy.

Identification of antigen-specific human monoclonal antibodies using high-throughput sequencing of the antibody repertoire.

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Liu, Ju; Li, Ruihua; Liu, Kun; Li, Liangliang; Zai, Xiaodong; Chi, Xiangyang; Fu, Ling; Xu, Junjie; Chen, Wei

2016-04-22

High-throughput sequencing of the antibody repertoire provides a large number of antibody variable region sequences that can be used to generate human monoclonal antibodies. However, current screening methods for identifying antigen-specific antibodies are inefficient. In the present study, we developed an antibody clone screening strategy based on clone dynamics and relative frequency, and used it to identify antigen-specific human monoclonal antibodies. Enzyme-linked immunosorbent assay showed that at least 52% of putative positive immunoglobulin heavy chains composed antigen-specific antibodies. Combining information on dynamics and relative frequency improved identification of positive clones and elimination of negative clones. and increase the credibility of putative positive clones. Therefore the screening strategy could simplify the subsequent experimental screening and may facilitate the generation of antigen-specific antibodies. Copyright © 2016 Elsevier Inc. All rights reserved.

Antigen and Memory CD8 T Cells: Were They Both Right?

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Epelman Slava

2007-06-01

Full Text Available Picture yourself as a researcher in immunology. To begin your project, you ask a question: Do CD8 T cells require antigen to maintain a memory response? This question is of prime importance to numerous medical fields. In chronologic order, you digest the literature, but unfortunately, you hit a major stumbling block in the 1990s. The crux of the problem is that which so often happens in science: two well-recognized, capable groups emerge with diametrically opposed conclusions, leaving you pondering which set of wellcontrolled data to believe. Fortunately, years later, a surprising group of articles sheds light on this mystery and subtly reconciles these two positions.

Plasma membrane associated, virus-specific polypeptides required for the formation of target antigen complexes recognized by virus-specific cytotoxic T lymphocytes

International Nuclear Information System (INIS)

Domber, E.A.

1986-01-01

These studies were undertaken to define some of the poxvirus-specific target antigens which are synthesized in infected cells and recognized by vaccinia virus-specific CTLs (VV-CTLs). Since vaccinia virus infected, unmanipulated target cells express numerous virus-specific antigens on the plasma membrane, attempts were made to manipulate expression of the poxvirus genome after infection so that one or a few defined virus-specified antigens were expressed on the surface of infected cells. In vitro [ 51 Cr]-release assays determined that viral DNA synthesis and expression of late viral proteins were not necessary to form a target cell which was fully competent for lysis by VV-CTLs. Under the conditions employed in these experiments, 90-120 minutes of viral protein synthesis were necessary to produce a competent cell for lysis by VV-CTLs. In order to further inhibit the expression of early viral proteins in infected cells, partially UV-inactivated vaccinia virus was employed to infect target cells. It was determined that L-cells infected with virus preparations which had been UV-irradiated for 90 seconds were fully competent for lysis by VV-CTLs. Cells infected with 90 second UV-irr virus expressed 3 predominant, plasma membrane associated antigens of 36-37K, 27-28K, and 19-17K. These 3 viral antigens represent the predominant membrane-associated viral antigens available for interaction with class I, major histocompatibility antigens and hence are potential target antigens for VV-CTLs

Prostate Cancer Detection and Prognosis: From Prostate Specific Antigen (PSA) to Exosomal Biomarkers.

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Filella, Xavier; Foj, Laura

2016-10-26

Prostate specific antigen (PSA) remains the most used biomarker in the management of early prostate cancer (PCa), in spite of the problems related to false positive results and overdiagnosis. New biomarkers have been proposed in recent years with the aim of increasing specificity and distinguishing aggressive from non-aggressive PCa. The emerging role of the prostate health index and the 4Kscore is reviewed in this article. Both are blood-based tests related to the aggressiveness of the tumor, which provide the risk of suffering PCa and avoiding negative biopsies. Furthermore, the use of urine has emerged as a non-invasive way to identify new biomarkers in recent years, including the PCA3 and TMPRSS2:ERG fusion gene. Available results about the PCA3 score showed its usefulness to decide the repetition of biopsy in patients with a previous negative result, although its relationship with the aggressiveness of the tumor is controversial. More recently, aberrant microRNA expression in PCa has been reported by different authors. Preliminary results suggest the utility of circulating and urinary microRNAs in the detection and prognosis of PCa. Although several of these new biomarkers have been recommended by different guidelines, large prospective and comparative studies are necessary to establish their value in PCa detection and prognosis.

Effects of Aging on General and Specific Memory for Impressions

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Megan J. Limbert

2018-05-01

Full Text Available Despite the number of documented declines in memory with age, memory for socioemotional information can be preserved into older adulthood. These studies assessed whether memory for character information could be preserved with age, and how the general versus specific nature of the information tested affected outcomes. We hypothesized that memory for general impressions would be preserved with age, but that memory for specific details would be impaired. In two experiments, younger and older adults learned character information about individuals characterized as positive, neutral, or negative. Participants then retrieved general impressions and specific information for each individual. The testing conditions in Experiment 2 discouraged deliberate recall. In Experiment 1, we found that younger performed better than older adults on both general and specific memory measures. Although age differences in memory for specific information persisted in Experiment 2, we found that younger and older adults remembered general impressions to a similar extent when testing conditions encouraged the use of “gut impressions” rather than deliberate retrieval from memory. We conclude that aging affects memory for specific character information, but memory for general impressions can be age-equivalent. Furthermore, there is no evidence for a positivity bias or differences in the effects of valence on memory across the age groups.

Immunoregulatory adherent cells in human tuberculosis: radiation-sensitive antigen-specific suppression by monocytes

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Kleinhenz, M.E.; Ellner, J.J.

1985-07-01

In human tuberculosis, adherent mononuclear cells (AMC) selectively depress in vitro responses to the mycobacterial antigen tuberculin purified protein derivative (PPD). The phenotype of this antigen-specific adherent suppressor cell was characterized by examining the functional activity of adherent cells after selective depletion of sheep erythrocyte-rosetting T cells or OKM1-reactive monocytes. Adherent cell suppression was studied in the (/sup 3/H)thymidine-incorporation microculture assay by using T cells rigorously depleted of T cells with surface receptors for the Fc portion of IgG (T gamma cells) as antigen-responsive cells. PPD-induced (/sup 3/H)thymidine incorporation by these non gamma T cells was uniformly reduced (mean, 42% +/- 10% (SD)) when autologous AMC were added to non gamma T cells at a ratio of 1:2. Antigen-specific suppression by AMC was not altered by depletion of sheep erythrocyte-rosetting T cells or treatment with indomethacin. However, AMC treated with OKM1 and complement or gamma irradiation (1,500 rads) no longer suppressed tuberculin responses in vitro. These studies identify the antigen-specific adherent suppressor cell in tuberculosis as an OKM1-reactive, non-erythrocyte-rosetting monocyte. The radiosensitivity of this monocyte immunoregulatory function may facilitate its further definition.

Immunoregulatory adherent cells in human tuberculosis: radiation-sensitive antigen-specific suppression by monocytes

International Nuclear Information System (INIS)

Kleinhenz, M.E.; Ellner, J.J.

1985-01-01

In human tuberculosis, adherent mononuclear cells (AMC) selectively depress in vitro responses to the mycobacterial antigen tuberculin purified protein derivative (PPD). The phenotype of this antigen-specific adherent suppressor cell was characterized by examining the functional activity of adherent cells after selective depletion of sheep erythrocyte-rosetting T cells or OKM1-reactive monocytes. Adherent cell suppression was studied in the [ 3 H]thymidine-incorporation microculture assay by using T cells rigorously depleted of T cells with surface receptors for the Fc portion of IgG (T gamma cells) as antigen-responsive cells. PPD-induced [ 3 H]thymidine incorporation by these non gamma T cells was uniformly reduced (mean, 42% +/- 10% [SD]) when autologous AMC were added to non gamma T cells at a ratio of 1:2. Antigen-specific suppression by AMC was not altered by depletion of sheep erythrocyte-rosetting T cells or treatment with indomethacin. However, AMC treated with OKM1 and complement or gamma irradiation (1,500 rads) no longer suppressed tuberculin responses in vitro. These studies identify the antigen-specific adherent suppressor cell in tuberculosis as an OKM1-reactive, non-erythrocyte-rosetting monocyte. The radiosensitivity of this monocyte immunoregulatory function may facilitate its further definition

Detection of Clonorchis sinensis circulating antigen in sera from Chinese patients by immunomagnetic bead ELISA based on IgY.

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Ge Nie

Full Text Available BACKGROUND: Clonorchiasis, caused by Clonorchis sinensis, is widely distributed in Southeast Asia including China. Clonorchiasis is included in control programs of neglected tropical diseases by World Health Organization (WHO because it is one of the major health problems in most endemic areas. Diagnosis of clonorchiasis plays a key role in the control programs. However, so far, there is no satisfactory method for clonorchiasis because of low sensitivity, poor practicality and high false positivity of available diagnostic tools. METHODOLOGY/PRINCIPAL FINDINGS: We developed an immunomagnetic bead enzyme-linked immunosorbent assay (ELISA based on IgY (egg yolk immunoglobulin against cysteine proteinase of C. sinensis for detection of circulating antigen in serum samples of patients infected with C. sinensis. The polyclonal IgY, coated with magnetic beads, was used as a capture antibody and a monoclonal IgG labeled with horseradish peroxidase as a detection antibody in the IgY-based immunomagnetic bead ELISA system (IgY-IMB-ELISA. The results showed that the sensitivity of IgY-IMB-ELISA was 93.3% (14 of 15 in cases of heavy infection (5000 to 9999 eggs per gram feces, i.e, EPG 5000-9999, 86.7% (13 of 15 in cases of moderate infection (EPG 1000-4999 and 75.0% (9 of 12 in cases of light infection (EPG <1000 of clonorchiasis. Together 36 of total 42 (85.7% serum samples of human clonorchiasis gave a positive reaction. There was a significant correlation between ELISA optical density and egg counts (EPG with a correlation coefficient of 0.83 in total 42 patients. There were no positive results in patients with trichinosis (n = 10 or cysticercosis (n = 10. Cross-reactivity was 6.7% (2 of 30 with schistosomiasis japonica and 10.0% (3 of 30 with paragonimiasis, respectively. No positive reaction was found in 20 healthy persons. CONCLUSIONS: Our findings suggest that IgY-IMB-ELISA appears to be a sensitive and specific assay for detection of circulating

Detection of Clonorchis sinensis circulating antigen in sera from Chinese patients by immunomagnetic bead ELISA based on IgY.

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Nie, Ge; Wang, Ting; Lu, Shengjun; Liu, Wenqi; Li, Yonglong; Lei, Jiahui

2014-01-01

Clonorchiasis, caused by Clonorchis sinensis, is widely distributed in Southeast Asia including China. Clonorchiasis is included in control programs of neglected tropical diseases by World Health Organization (WHO) because it is one of the major health problems in most endemic areas. Diagnosis of clonorchiasis plays a key role in the control programs. However, so far, there is no satisfactory method for clonorchiasis because of low sensitivity, poor practicality and high false positivity of available diagnostic tools. We developed an immunomagnetic bead enzyme-linked immunosorbent assay (ELISA) based on IgY (egg yolk immunoglobulin) against cysteine proteinase of C. sinensis for detection of circulating antigen in serum samples of patients infected with C. sinensis. The polyclonal IgY, coated with magnetic beads, was used as a capture antibody and a monoclonal IgG labeled with horseradish peroxidase as a detection antibody in the IgY-based immunomagnetic bead ELISA system (IgY-IMB-ELISA). The results showed that the sensitivity of IgY-IMB-ELISA was 93.3% (14 of 15) in cases of heavy infection (5000 to 9999 eggs per gram feces, i.e, EPG 5000-9999), 86.7% (13 of 15) in cases of moderate infection (EPG 1000-4999) and 75.0% (9 of 12) in cases of light infection (EPG <1000) of clonorchiasis. Together 36 of total 42 (85.7%) serum samples of human clonorchiasis gave a positive reaction. There was a significant correlation between ELISA optical density and egg counts (EPG) with a correlation coefficient of 0.83 in total 42 patients. There were no positive results in patients with trichinosis (n = 10) or cysticercosis (n = 10). Cross-reactivity was 6.7% (2 of 30) with schistosomiasis japonica and 10.0% (3 of 30) with paragonimiasis, respectively. No positive reaction was found in 20 healthy persons. Our findings suggest that IgY-IMB-ELISA appears to be a sensitive and specific assay for detection of circulating antigen in human clonorchiasis.

Diagnostic value of prostate-specific antigen in women with polycystic ovary syndrome

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Farahnaz Mardanian

2011-01-01

Full Text Available Background: Polycystic ovary syndrome (PCOS is the most common endocrine disorder in women. Its presentation is that of irregular menstruation associated with ovulation defects. Because of adverse outcomes such as metabolic and cardiovascular disorders, its diagnosis and treatment is very important. Therefore, the diagnostic value of prostatespecific antigen (PSA in women with polycystic ovary syndrome was evaluated. Methods: A total of 32 women with PCOS and 32 aged matched healthy females were recruited in this case-control study. The subjects were compared by means of metabolic measures and serum PSA level. The correlations between these markers were evaluated. Sensitivity and specificity values and cut off levels of PSA were established for diagnosis of PCOS. Results: Mean PSA, Ferriman Gallwey score (FGS, luteinizing hormone/follicle stimulating hormone ratio (LH/FSH, testosterone, dehydroepiandrosterone sulfate (DHEAS, 17α hydroxyprogesterone (17α HP levels were significantly higher in PCOS (P<0.001, respectively. PSA levels greater than 0.07 ng/ml yielded a sensitivity of 91% and specificity of 82%, and was helpful as a diagnostic tool for women with PCOS. Circulating androgens and hirsutism were associated with higher levels of PSA in PCOS women. Conclusions: Our results showed direct correlation between PSA, hirsutism and hyperandrogemsm state. Therefore, it seems logical to use PSA level for detection of hyperandrogemsm state in women.

Trypanosoma cruzi vaccine candidate antigens Tc24 and TSA-1 recall memory immune response associated with HLA-A and -B supertypes in Chagasic chronic patients from Mexico.

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Villanueva-Lizama, Liliana E; Cruz-Chan, Julio V; Aguilar-Cetina, Amarú Del C; Herrera-Sanchez, Luis F; Rodriguez-Perez, Jose M; Rosado-Vallado, Miguel E; Ramirez-Sierra, Maria J; Ortega-Lopez, Jaime; Jones, Kathryn; Hotez, Peter; Bottazzi, Maria Elena; Dumonteil, Eric

2018-01-01

Trypanosoma cruzi antigens TSA-1 and Tc24 have shown promise as vaccine candidates in animal studies. We evaluated here the recall immune response these antigens induce in Chagasic patients, as a first step to test their immunogenicity in humans. We evaluated the in vitro cellular immune response after stimulation with recombinant TSA-1 (rTSA-1) or recombinant Tc24 (rTc24) in mononuclear cells of asymptomatic Chagasic chronic patients (n = 20) compared to healthy volunteers (n = 19) from Yucatan, Mexico. Proliferation assays, intracellular cytokine staining, cytometric bead arrays, and memory T cell immunophenotyping were performed by flow cytometry. Peripheral blood mononuclear cells (PBMC) from Chagasic patients showed significant proliferation after stimulation with rTc24 and presented a phenotype of T effector memory cells (CD45RA-CCR7-). These cells also produced IFN-γ and, to a lesser extent IL10, after stimulation with rTSA-1 and rTc24 proteins. Overall, both antigens recalled a broad immune response in some Chagasic patients, confirming that their immune system had been primed against these antigens during natural infection. Analysis of HLA-A and HLA-B allele diversity by PCR-sequencing indicated that HLA-A03 and HLA-B07 were the most frequent supertypes in this Mexican population. Also, there was a significant difference in the frequency of HLA-A01 and HLA-A02 supertypes between Chagasic patients and controls, while the other alleles were evenly distributed. Some aspects of the immune response, such as antigen-induced IFN-γ production by CD4+ and CD8+ T cells and CD8+ proliferation, showed significant association with specific HLA-A supertypes, depending on the antigen considered. In conclusion, our results confirm the ability of both TSA-1 and Tc24 recombinant proteins to recall an immune response induced by the native antigens during natural infection in at least some patients. Our data support the further development of these antigens as therapeutic

Usefulness of transrectal ultrasound in diagnosing prostate cancer: comparison with digital rectal examination, prostate-specific antigen and prostate-specific antigen density

International Nuclear Information System (INIS)

Yoon, Jung Hwan; Kim, Bo Hyun; Choi, Sang Hee; Kim, Seung Hoon; Choi, Han Yong; Chai, Soo Eung; Yoon, Hye Kyung; Lee, Soon Jin; Choo, In Wook; Kim, Bo Kyung

1998-01-01

To determine the usefulness of transrectal ultrasonography (TRUS) in diagnosing prostate cancer by comparing the sensitivity, specificity, accuracy, and positive and negative predictive values of TRUS with those of serum prostate-specific antigen (PSA), prostate-specific antigen density (PSAD) and digital rectal examination (DRE). Two hundred and ten consecutive patients underwent TRUS-guided prostate biopsy due to elevated PSA and/or abnormal findings on TRUS or DRE. The TRUS findings were analyzed and correlated with pathological diagnosis. PSAD was calculated by dividing the serum PSA level by the prostate volume calculated on TRUS. The sensitivity, specificity, accuracy, and positive and negative predictive values of TRUS were compared with those of PSA, PSAD and DRE. Using ROC curve analysis, the combinations of these diagnostic methods were also evaluated for the determination of efficacy in diagnosing prostate cancer. The sensitivity and specificity of serum PSA (cut-off level, 4ng/ml), PSAD (cut-off level, 0.15ng/ml/cm 3 ), DRE, and TRUS were 96%/17%, 96%/37%, 72%/62%, and 89%/68%, respectively. On TRUS, the sensitivity and specificity of low echoic lesions and those of irregular outer margin were 89%/69%, and 60%/90%, respectively. TRUS was statistically more accurate than other diagnostic methods. Of the combinations of diagnostic methods, TRUS and PSAD were most accurate. TRUS demonstrated lower sensitivity but higher specificity than PSA or PSAD. Although it is an accurate modality for the diagnosis of prostate cancer, it cannot be used as a confirmative test due to its relatively low positive predictive value. A combination of diagnostic methods and random biopsy is needed in patients in whom prostate cancer is suspected.=20

Vaxfectin enhances antigen specific antibody titers and maintains Th1 type immune responses to plasmid DNA immunization.

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Reyes, L; Hartikka, J; Bozoukova, V; Sukhu, L; Nishioka, W; Singh, G; Ferrari, M; Enas, J; Wheeler, C J; Manthorpe, M; Wloch, M K

2001-06-14

Antigen specific immune responses were characterized after intramuscular immunization of BALB/c mice with 5 antigen encoding plasmid DNAs (pDNAs) complexed with Vaxfectin, a cationic lipid formulation. Vaxfectin increased IgG titers for all of the antigens with no effect on the CTL responses to the 2 antigens for which CTL assays were performed. Both antigen specific IgG1 and IgG2a were increased, although IgG2a remained greater than IgG1. Furthermore, Vaxfectin had no effect on IFN-gamma or IL-4 production by splenocytes re-stimulated with antigen, suggesting that the Th1 type responses typical of intramuscular pDNA immunization were not altered. Studies with IL-6 -/- mice suggest that the antibody enhancement is IL-6 dependent and results in a correlative increase in antigen specific antibody secreting cells.

Human seminal proteinase and prostate-specific antigen are the ...

Indian Academy of Sciences (India)

https://www.ias.ac.in/article/fulltext/jbsc/033/02/0195-0207. Keywords. Kallikrein; prostate cancer biomarker; proteinase activity; seminal plasma; tumour proliferation and metastasis; therapeutic target. Abstract. Human seminal proteinase and prostate-specific antigen (PSA) were each isolated from human seminal fluid and ...

Direct Lymph Node Vaccination of Lentivector/Prostate-Specific Antigen is Safe and Generates Tissue-Specific Responses in Rhesus Macaques

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Bryan C. Au

2016-02-01

Full Text Available Anti-cancer immunotherapy is emerging from a nadir and demonstrating tangible benefits to patients. A variety of approaches are now employed. We are invoking antigen (Ag-specific responses through direct injections of recombinant lentivectors (LVs that encode sequences for tumor-associated antigens into multiple lymph nodes to optimize immune presentation/stimulation. Here we first demonstrate the effectiveness and antigen-specificity of this approach in mice challenged with prostate-specific antigen (PSA-expressing tumor cells. Next we tested the safety and efficacy of this approach in two cohorts of rhesus macaques as a prelude to a clinical trial application. Our vector encodes the cDNA for rhesus macaque PSA and a rhesus macaque cell surface marker to facilitate vector titering and tracking. We utilized two independent injection schemas demarcated by the timing of LV administration. In both cohorts we observed marked tissue-specific responses as measured by clinical evaluations and magnetic resonance imaging of the prostate gland. Tissue-specific responses were sustained for up to six months—the end-point of the study. Control animals immunized against an irrelevant Ag were unaffected. We did not observe vector spread in test or control animals or perturbations of systemic immune parameters. This approach thus offers an “off-the-shelf” anti-cancer vaccine that could be made at large scale and injected into patients—even on an out-patient basis.

Direct Lymph Node Vaccination of Lentivector/Prostate-Specific Antigen is Safe and Generates Tissue-Specific Responses in Rhesus Macaques.

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Au, Bryan C; Lee, Chyan-Jang; Lopez-Perez, Orlay; Foltz, Warren; Felizardo, Tania C; Wang, James C M; Huang, Ju; Fan, Xin; Madden, Melissa; Goldstein, Alyssa; Jaffray, David A; Moloo, Badru; McCart, J Andrea; Medin, Jeffrey A

2016-02-19

Anti-cancer immunotherapy is emerging from a nadir and demonstrating tangible benefits to patients. A variety of approaches are now employed. We are invoking antigen (Ag)-specific responses through direct injections of recombinant lentivectors (LVs) that encode sequences for tumor-associated antigens into multiple lymph nodes to optimize immune presentation/stimulation. Here we first demonstrate the effectiveness and antigen-specificity of this approach in mice challenged with prostate-specific antigen (PSA)-expressing tumor cells. Next we tested the safety and efficacy of this approach in two cohorts of rhesus macaques as a prelude to a clinical trial application. Our vector encodes the cDNA for rhesus macaque PSA and a rhesus macaque cell surface marker to facilitate vector titering and tracking. We utilized two independent injection schemas demarcated by the timing of LV administration. In both cohorts we observed marked tissue-specific responses as measured by clinical evaluations and magnetic resonance imaging of the prostate gland. Tissue-specific responses were sustained for up to six months-the end-point of the study. Control animals immunized against an irrelevant Ag were unaffected. We did not observe vector spread in test or control animals or perturbations of systemic immune parameters. This approach thus offers an "off-the-shelf" anti-cancer vaccine that could be made at large scale and injected into patients-even on an out-patient basis.

Manipulating the Lewis antigen specificity of the cholesterol-dependent cytolysin lectinolysin

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Sara eLawrence

2012-11-01

Full Text Available The cholesterol-dependent cytolysins (CDCs attack cells by punching large holes in their membranes. Lectinolysin from Streptococcus mitis is unique among CDCs due to the presence of an N-terminal lectin domain that enhances the pore-forming activity of the toxin. We recently determined the crystal structures of the lectin domain in complex with various glycans. These structures revealed the molecular basis for the Lewis antigen specificity of the toxin. Based on this information we have used in silico molecular modelling to design a mutant toxin, which we predicted would increase its specificity for Lewis y, an antigen found on the surface of cancer cells. Surprisingly, we found by surface plasmon resonance binding experiments that the resultant mutant lectin domain exhibited higher specificity for Lewis b antigens instead. We then undertook comparative crystallographic and molecular dynamics simulation studies of the wild-type and mutant lectin domains to understand the molecular basis for the disparity between the theoretical and experimental results. The crystallographic results revealed that the net number of interactions between Lewis y and wild-type versus mutant was unchanged whereas there was a loss of a hydrogen bond between mutant and Lewis b compared to wild-type. In contrast, the molecular dynamics studies revealed that the Lewis b antigen spent more time in the binding pocket of the mutant compared to wild-type and the reverse was true for Lewis y. The results of these simulation studies are consistent with the conclusions drawn from the surface plasmon resonance studies. This work is part of a program to engineer lectinolysin so that it will target and kill specific cells in human diseases.

Circulating Gut-Homing (α4β7+) Plasmablast Responses against Shigella Surface Protein Antigens among Hospitalized Patients with Diarrhea.

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Sinha, Anuradha; Dey, Ayan; Saletti, Giulietta; Samanta, Pradip; Chakraborty, Partha Sarathi; Bhattacharya, M K; Ghosh, Santanu; Ramamurthy, T; Kim, Jae-Ouk; Yang, Jae Seung; Kim, Dong Wook; Czerkinsky, Cecil; Nandy, Ranjan K

2016-07-01

Developing countries are burdened with Shigella diarrhea. Understanding mucosal immune responses associated with natural Shigella infection is important to identify potential correlates of protection and, as such, to design effective vaccines. We performed a comparative analysis of circulating mucosal plasmablasts producing specific antibodies against highly conserved invasive plasmid antigens (IpaC, IpaD20, and IpaD120) and two recently identified surface protein antigens, pan-Shigella surface protein antigen 1 (PSSP1) and PSSP2, common to all virulent Shigella strains. We examined blood and stool specimens from 37 diarrheal patients admitted to the Infectious Diseases & Beliaghata General Hospital, Kolkata, India. The etiological agent of diarrhea was investigated in stool specimens by microbiological methods and real-time PCR. Gut-homing (α4β7 (+)) antibody-secreting cells (ASCs) were isolated from patient blood by means of combined magnetic cell sorting and two-color enzyme-linked immunosorbent spot (ELISPOT) assay. Overall, 57% (21 of 37) and 65% (24 of 37) of the patients were positive for Shigella infection by microbiological and real-time PCR assays, respectively. The frequency of α4β7 (+) IgG ASC responders against Ipas was higher than that observed against PSSP1 or PSSP2, regardless of the Shigella serotype isolated from these patients. Thus, α4β7 (+) ASC responses to Ipas may be considered an indirect marker of Shigella infection. The apparent weakness of ASC responses to PSSP1 is consistent with the lack of cross-protection induced by natural Shigella infection. The finding that ASC responses to IpaD develop in patients with recent-onset shigellosis indicates that such responses may not be protective or may wane too rapidly and/or be of insufficient magnitude. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Structural and antigenic variation among diverse clade 2 H5N1 viruses.

Directory of Open Access Journals (Sweden)

David A Shore

Full Text Available Antigenic variation among circulating H5N1 highly pathogenic avian influenza A viruses mandates the continuous production of strain-specific pre-pandemic vaccine candidates and represents a significant challenge for pandemic preparedness. Here we assessed the structural, antigenic and receptor-binding properties of three H5N1 HPAI virus hemagglutinins, which were recently selected by the WHO as vaccine candidates [A/Egypt/N03072/2010 (Egypt10, clade 2.2.1, A/Hubei/1/2010 (Hubei10, clade 2.3.2.1 and A/Anhui/1/2005 (Anhui05, clade 2.3.4]. These analyses revealed that antigenic diversity among these three isolates was restricted to changes in the size and charge of amino acid side chains at a handful of positions, spatially equivalent to the antigenic sites identified in H1 subtype viruses circulating among humans. All three of the H5N1 viruses analyzed in this study were responsible for fatal human infections, with the most recently-isolated strains, Hubei10 and Egypt10, containing multiple residues in the receptor-binding site of the HA, which were suspected to enhance mammalian transmission. However, glycan-binding analyses demonstrated a lack of binding to human α2-6-linked sialic acid receptor analogs for all three HAs, reinforcing the notion that receptor-binding specificity contributes only partially to transmissibility and pathogenesis of HPAI viruses and suggesting that changes in host specificity must be interpreted in the context of the host and environmental factors, as well as the virus as a whole. Together, our data reveal structural linkages with phylogenetic and antigenic analyses of recently emerged H5N1 virus clades and should assist in interpreting the significance of future changes in antigenic and receptor-binding properties.

Phase-II Associative Memory ASIC Specifications

CERN Document Server

Stabile, Alberto; Warren, Matthew; Green, Barry; Konstantinidis, Nikolaos; Motuk, Halil Erdem; Frontini, Luca; Liberali, Valentino; Crescioli, Francesco; Fedi, Giacomo; Sotiropoulou, Calliope-louisa; De Canio, Francesco; Traversi, Gianluca; Shojaii, Seyed Ruhollah; Kubota, Takashi; Calderini, Giovanni; Palla, Fabrizio; Checcucci, Bruno; Spiller, Laurence Anthony; Mcnamara, Peter Charles

2018-01-01

This documents defines the specifications for the Associative Memory ASIC for Phase-II. The work-flow toward the final ASIC is organized in the following three steps • AM08 prototype: small area MPW prototype to test all the full custom features, the VHDL logic and the I/O. This chip must be fully functional with smaller memory area than the final ASIC; • AM09pre pre-production: full area ASIC to be fabricated with a full-mask set pilot run. Production corner wafers will be created; • AM09 production: full area ASIC with refinements for the mass production. The AM09 will be developed built on the AM08 extending the memory area, therefore the specification of both versions must be compatible.

Heparin-associated thrombocytopenia: antibody binding specificity to platelet antigens.

Science.gov (United States)

Lynch, D M; Howe, S E

1985-11-01

Sera from four patients with heparin-associated thrombocytopenia (HAT) were evaluated by a quantitative enzyme-linked immunosorbent assay (ELISA) to detect heparin-dependent serum platelet-bindable immunoglobulin (S-PBIg) and by Western blotting and immunoprecipitation to investigate the specificity of the antibody binding. All HAT sera showed mildly increased S-PBIg (mean, 7.8 fg per platelet; normal, less than 6.0 fg per platelet) to intact target platelets in the ELISA, which was markedly increased in the presence of heparin (mean, 20.9 fg per platelet). This increase was 20-fold greater than normal control sera, which showed a mean differential increase of only 0.5 fg per platelet. Immunoglobulin binding specificity to platelet antigens was investigated using sodium dodecyl sulfate-polyacrylamide gel electrophoresis of platelet lysate with transfer of the platelet fractions onto nitrocellulose strips (Western blotting) and subsequent immunoassay using HAT and normal sera. In the presence of heparin, the four HAT patients demonstrated increased binding of immunoglobulin to platelet antigens of apparent molecular weights of 180, 124, and 82 kd. Radiolabeled heparin when incubated with HAT sera, normal sera, or albumin blanks bound to platelet proteins of the same apparent molecular weights. These observations are consistent with current hypotheses suggesting that HAT antibody is directed to heparin-platelet complexes or, alternatively, that heparin induces conformational change of antigenic sites on the platelet membrane.

Duration and specificity of olfactory nonassociative memory.

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Freedman, Kaitlin G; Radhakrishna, Sreya; Escanilla, Olga; Linster, Christiane

2013-05-01

Olfactory habituation is a simple form of nonassociative memory in which responsiveness to stable but behaviorally nonsignificant stimuli is decreased. Olfactory habituation has recently become a paradigm widely used to probe the neural substrate underlying olfactory perception and memory. This simple behavioral paradigm has been used successfully used to probe many aspects of olfactory processing, and it has recently become clear that the neural processes underlying olfactory habituation can depend on the task parameters used. We here further investigate memory specificity and duration using 2 variations in task parameters: the number of habituation trials and the time delay between habituation and cross-habituation testing. We find that memory specificity increases with the number of habituation trials but decreases with time after the last habituation trial.

Dihydrolipoamide dehydrogenase-Lpd (Rv0462)-specific T cell recall responses are higher in healthy household contacts of TB: a novel immunodominant antigen from M. tuberculosis.

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Devasundaram, Santhi; Raja, Alamelu

2017-07-01

The partial effectiveness against pulmonary tuberculosis (PTB), displayed by the existing tuberculosis (TB) vaccine, bacillus Calmette-Guérin (BCG), highlights the need for novel vaccines to replace or improve BCG. In TB immunology, antigen-specific cellular immune response is frequently considered indispensable. Latency-associated antigens are intriguing as targets for TB vaccine development. The mycobacterial protein, dihydrolipoamide dehydrogenase (Lpd; Rv0462), the third enzyme of the pyruvate dehydrogenase (PDH) complex, facilitates Mycobacterium tuberculosis to resist host reactive nitrogen intermediates. Multicolor flow cytometry analysis of whole-blood cultures showed higher Lpd-specific Th1 recall response (IFN-γ, TNF-α, and IL-2; P = 0.0006) and memory CD4 + and CD8 + T cells (CCR7 + CD45RA - and CCR7 - CD45RA - ) in healthy household contacts (HHC) of TB ( P < 0.0001), which is comparable with or higher than the standard antigens, ESAT-6 and CFP-10. The frequency of Lpd-specific multifunctional T cells was higher in HHC compared with PTB patients. However, there is no significant statistical correlation. Regulatory T cell (T reg ) analysis of HHCs and active TB patients demonstrated very low Lpd-specific CD4 + T regs relative to ESAT-6 and CFP-10. Our study demonstrates that the Lpd antigen induces a strong cellular immune response in healthy mycobacteria-infected individuals. In consideration of this population having demonstrated immunologic protection against active TB disease development, our data are encouraging about the possible use of Lpd as a target for further TB subunit vaccine development. © Society for Leukocyte Biology.

Antigen-specific and non-specific CD4+ T cell recruitment and proliferation during influenza infection

International Nuclear Information System (INIS)

Chapman, Timothy J.; Castrucci, Maria R.; Padrick, Ryan C.; Bradley, Linda M.; Topham, David J.

2005-01-01

To track epitope-specific CD4 + T cells at a single-cell level during influenza infection, the MHC class II-restricted OVA 323-339 epitope was engineered into the neuraminidase stalk of influenza/A/WSN, creating a surrogate viral antigen. The recombinant virus, influenza A/WSN/OVA II , replicated well, was cleared normally, and stimulated both wild-type and DO11.10 or OT-II TCR transgenic OVA-specific CD4 + T cells. OVA-specific CD4 T cells proliferated during infection only when the OVA epitope was present. However, previously primed (but not naive) transgenic CD4 + T cells were recruited to the infected lung both in the presence and absence of the OVA 323-339 epitope. These data show that, when primed, CD4 + T cells may traffic to the lung in the absence of antigen, but do not proliferate. These results also document a useful tool for the study of CD4 T cells in influenza infection

Addiction memory as a specific, individually learned memory imprint.

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Böning, J

2009-05-01

The construct of "addiction memory" (AM) and its importance for relapse occurrence has been the subject of discussion for the past 30 years. Neurobiological findings from "social neuroscience" and biopsychological learning theory, in conjunction with construct-valid behavioral pharmacological animal models, can now also provide general confirmation of addiction memory as a pathomorphological correlate of addiction disorders. Under multifactorial influences, experience-driven neuronal learning and memory processes of emotional and cognitive processing patterns in the specific individual "set" and "setting" play an especially pivotal role in this connection. From a neuropsychological perspective, the episodic (biographical) memory, located at the highest hierarchical level, is of central importance for the formation of the AM in certain structural and functional areas of the brain and neuronal networks. Within this context, neuronal learning and conditioning processes take place more or less unconsciously and automatically in the preceding long-term-memory systems (in particular priming and perceptual memory). They then regulate the individually programmed addiction behavior implicitly and thus subsequently stand for facilitated recollection of corresponding, previously stored cues or context situations. This explains why it is so difficult to treat an addiction memory, which is embedded above all in the episodic memory, from the molecular carrier level via the neuronal pattern level through to the psychological meaning level, and has thus meanwhile become a component of personality.

Phenotypic analysis of perennial airborne allergen-specific CD4+ T cells in atopic and non-atopic individuals.

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Crack, L R; Chan, H W; McPherson, T; Ogg, G S

2011-11-01

Accumulating evidence suggests that T cells play an important role in the pathogenesis of atopic dermatitis (AD); yet, little is known of the differentiation status of CD4+ T cells specific for common environmental allergens, such as the major cat allergen, Fel d 1. To determine the frequency, differentiation phenotype and function of circulating Fel d 1-specific CD4+ T cells in adult individuals with severe persistent AD in comparison with healthy controls. Using HLA class II tetrameric complexes based on a HLA-DPB1*0401-restricted Fel d 1 epitope, ex vivo and cultured T cell frequency and phenotype were analysed in individuals with AD and healthy controls. Cytokine secretion was measured by ex vivo and cultured IL-4 and IFN-γ ELISpots. Ex vivo Fel d 1-specific DPB1*0401-restricted CD4+ T cells in both atopics and non-atopics express high levels of CCR7, CD62L, CD27 and CD28, placing the cells largely within the central memory subgroup. However, the functional phenotype was distinct, with greater IL-4 production from the cells derived from atopics, which correlated with disease severity. Circulating Fel d 1-specific DPB1*0401-restricted CD4+ T cells in both atopic and non-atopic donors maintain a central memory phenotype; however in atopics, the cells had greater Th2 effector function, compatible with a disease model of altered antigen delivery in atopic individuals. © 2011 Blackwell Publishing Ltd.

Antigen-Specific Polyclonal Cytotoxic T Lymphocytes Induced by Fusions of Dendritic Cells and Tumor Cells

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Shigeo Koido

2010-01-01

Full Text Available The aim of cancer vaccines is induction of tumor-specific cytotoxic T lymphocytes (CTLs that can reduce the tumor mass. Dendritic cells (DCs are potent antigen-presenting cells and play a central role in the initiation and regulation of primary immune responses. Thus, DCs-based vaccination represents a potentially powerful strategy for induction of antigen-specific CTLs. Fusions of DCs and whole tumor cells represent an alternative approach to deliver, process, and subsequently present a broad spectrum of antigens, including those known and unidentified, in the context of costimulatory molecules. Once DCs/tumor fusions have been infused back into patient, they migrate to secondary lymphoid organs, where the generation of antigen-specific polyclonal CTL responses occurs. We will discuss perspectives for future development of DCs/tumor fusions for CTL induction.

Effectiveness of the combined evaluation of KLK3 genetics and free-to-total prostate specific antigen ratio for prostate cancer diagnosis.

Science.gov (United States)

Zambon, Carlo-Federico; Prayer-Galetti, Tommaso; Basso, Daniela; Padoan, Andrea; Rossi, Elisa; Secco, Silvia; Pelloso, Michela; Fogar, Paola; Navaglia, Filippo; Moz, Stefania; Zattoni, Filiberto; Plebani, Mario

2012-10-01

Of serum prostate specific antigen variability 40% depends on inherited factors. We ascertained whether the knowledge of KLK3 genetics would enhance prostate specific antigen diagnostic performance in patients with clinical suspicion of prostate cancer. We studied 1,058 men who consecutively underwent prostate biopsy for clinical suspicion of prostate cancer. At histology prostate cancer was present in 401 cases and absent in 657. Serum total prostate specific antigen and the free-to-total prostate specific antigen ratio were determined. Four polymorphisms of the KLK3 gene (rs2569733, rs2739448, rs925013 and rs2735839) and 1 polymorphism of the SRD5A2 gene (rs523349) were studied. The influence of genetics on prostate specific antigen variability was evaluated by multivariate linear regression analysis. The performance of total prostate specific antigen and the free-to-total prostate specific antigen ratio alone or combined with a genetically based patient classification were defined by ROC curve analyses. For prostate cancer diagnosis the free-to-total prostate specific antigen ratio index alone (cutoff 11%) was superior to total prostate specific antigen (cutoff 4 ng/ml) and to free-to-total prostate specific antigen ratio reflex testing (positive predictive value 61%, 43% and 54%, respectively). Prostate specific antigen correlated with KLK3 genetics (rs2735839 polymorphism p = 0.001, and rs2569733, rs2739448 and rs925013 haplotype combination p = 0.003). In patients with different KLK3 genetics 2 optimal free-to-total prostate specific antigen ratio cutoffs (11% and 14.5%) were found. For free-to-total prostate specific antigen ratio values between 11% and 14.5% the prostate cancer probability ranged from 30.0% to 47.4% according to patient genetics. The free-to-total prostate specific antigen ratio is superior to total prostate specific antigen for prostate cancer diagnosis, independent of total prostate specific antigen results. Free-to-total prostate

Prostate-specific membrane antigen and its truncated form PSM'

Czech Academy of Sciences Publication Activity Database

Mlčochová, Petra; Bařinka, Cyril; Tykvart, Jan; Šácha, Pavel; Konvalinka, Jan

2009-01-01

Roč. 69, č. 5 (2009), s. 471-479 ISSN 0270-4137 R&D Projects: GA MŠk 1M0508 Institutional research plan: CEZ:AV0Z40550506 Keywords : prostate specific membrane antigen * glutamate carboxypeptidase II * prostate cancer Subject RIV: CE - Biochemistry Impact factor: 3.081, year: 2009

Predictive value of prostate-specific antigen for prostate cancer

DEFF Research Database (Denmark)

Shepherd, Leah; Borges, Alvaro Humberto; Ravn, Lene

2014-01-01

INTRODUCTION: Although prostate cancer (PCa) incidence is lower in HIV+ men than in HIV- men, the usefulness of prostate-specific antigen (PSA) screening in this population is not well defined and may have higher false negative rates than in HIV- men. We aimed to describe the kinetics and predict......INTRODUCTION: Although prostate cancer (PCa) incidence is lower in HIV+ men than in HIV- men, the usefulness of prostate-specific antigen (PSA) screening in this population is not well defined and may have higher false negative rates than in HIV- men. We aimed to describe the kinetics...... and predictive value of PSA in HIV+ men. METHODS: Men with PCa (n=21) and up to two matched controls (n=40) with prospectively stored plasma samples before PCa (or matched date in controls) were selected. Cases and controls were matched on date of first and last sample, age, region of residence and CD4 count...... at first sample date. Total PSA (tPSA), free PSA (fPSA), testosterone and sex hormone binding globulin (SHBG) were measured. Conditional logistic regression models investigated associations between markers and PCa. Sensitivity and specificity of using tPSA >4 µg/L to predict PCa was calculated. Mixed...

Medial prefrontal-hippocampal connectivity during emotional memory encoding predicts individual differences in the loss of associative memory specificity.

Science.gov (United States)

Berkers, Ruud M W J; Klumpers, Floris; Fernández, Guillén

2016-10-01

Emotionally charged items are often remembered better, whereas a paradoxical loss of specificity is found for associative emotional information (specific memory). The balance between specific and generalized emotional memories appears to show large individual differences, potentially related to differences in (the risk for) affective disorders that are characterized by 'overgeneralized' emotional memories. Here, we investigate the neural underpinnings of individual differences in emotional associative memory. A large group of healthy male participants were scanned while encoding associations of face-photographs and written occupational identities that were of either neutral ('driver') or negative ('murderer') valence. Subsequently, memory was tested by prompting participants to retrieve the occupational identities corresponding to each face. Whereas in both valence categories a similar amount of faces was labeled correctly with 'neutral' and 'negative' identities, (gist memory), specific associations were found to be less accurately remembered when the occupational identity was negative compared to neutral (specific memory). This pattern of results suggests reduced memory specificity for associations containing a negatively valenced component. The encoding of these negative associations was paired with a selective increase in medial prefrontal cortex activity and medial prefrontal-hippocampal connectivity. Individual differences in valence-specific neural connectivity were predictive of valence-specific reduction of memory specificity. The relationship between loss of emotional memory specificity and medial prefrontal-hippocampal connectivity is in line with the hypothesized role of a medial prefrontal-hippocampal circuit in regulating memory specificity, and warrants further investigations in individuals displaying 'overgeneralized' emotional memories. Copyright © 2016 Elsevier Inc. All rights reserved.

Observations of pretreatment prostate-specific antigen doubling time in 107 patients referred for definitive radiotherapy

International Nuclear Information System (INIS)

Lee, W. Robert; Hanks, Gerald E.; Corn, Benjamin W.; Schultheiss, Timothy E.

1995-01-01

Purpose: To determine pretreatment prostate-specific antigen doubling times (PSADT) in patients referred for definitive radiotherapy. Methods and Materials: One hundred and seven patients with histologically proven nonmetastatic prostate cancer and an elevated prostate-specific antigen (PSA) who were referred for radiation therapy had three serum PSA values obtained prior to the start of definitive therapy. Prostate-specific antigen doubling times were calculated by linear regression. Results: Prostate-specific antigen values increased during the period of observation in 78 patients (73%). Forty-three patients (40%) had calculated PSADT of less than 2 years and of those patients with pretreatment serum PSA values of greater than 10 ng/mL more than 50% has calculated PSADT of less than 2 years. Conclusions: A significant minority of patients referred for radiotherapy have calculated PSADT of less than 2 years. The significance of this relatively fast growth rate is as yet undetermined, but suggests that patients referred for radiotherapy may have aggressive disease prior to treatment

The CD8+ memory T-cell state of readiness is actively maintained and reversible

Science.gov (United States)

Allam, Atef; Conze, Dietrich B.; Giardino Torchia, Maria Letizia; Munitic, Ivana; Yagita, Hideo; Sowell, Ryan T.; Marzo, Amanda L.

2009-01-01

The ability of the adaptive immune system to respond rapidly and robustly upon repeated antigen exposure is known as immunologic memory, and it is thought that acquisition of memory T-cell function is an irreversible differentiation event. In this study, we report that many phenotypic and functional characteristics of antigen-specific CD8 memory T cells are lost when they are deprived of contact with dendritic cells. Under these circumstances, memory T cells reverted from G1 to the G0 cell-cycle state and responded to stimulation like naive T cells, as assessed by proliferation, dependence upon costimulation, and interferon-γ production, without losing cell surface markers associated with memory. The memory state was maintained by signaling via members of the tumor necrosis factor receptor superfamily, CD27 and 4-1BB. Foxo1, a transcription factor involved in T-cell quiescence, was reduced in memory cells, and stimulation of naive CD8 cells via CD27 caused Foxo1 to be phosphorylated and emigrate from the nucleus in a phosphatidylinositol-3 kinase–dependent manner. Consistent with these results, maintenance of G1 in vivo was compromised in antigen-specific memory T cells in vesicular stomatitis virus-infected CD27-deficient mice. Therefore, sustaining the functional phenotype of T memory cells requires active signaling and maintenance. PMID:19617575

Influence of memory theme and posttraumatic stress disorder on memory specificity in British and Iranian trauma survivors.

Science.gov (United States)

Jobson, Laura; Cheraghi, Sepideh

2016-09-01

This study investigated the influence of culture, memory theme and posttraumatic stress disorder (PTSD) on autobiographical memory specificity in Iranian and British trauma survivors. Participants completed the Autobiographical Memory Test and PTSD Diagnostic Scale. The results indicated that the British group provided significantly more personal-themed memories than the Iranian group, while the Iranian group provided significantly more social-themed memories than the British group. The British group also provided a significantly greater proportion of specific personal-themed and social-themed memories than the Iranian group. Overall, in both cultural groups memory specificity was found to be significantly correlated with PTSD symptoms. These findings provide further evidence that regardless of memory theme, specificity of autobiographical memories function to differentiate the self from others and reaffirm the independent self. They also further highlight that pan-culturally an overgeneral retrieval style may be employed by those with PTSD symptoms.

Prostatic specific antigen. From its early days until becoming a prostate cancer biomarker.

Science.gov (United States)

Dellavedova, T

2016-01-01

Prostate-specific antigen (PSA) has been since the mid 80's the most commonly used biomarker for measuring current and future risk of prostate cancer, for its early detection and to measure response to treatments and detecting recurrence in all stages of the disease. PSA's early development came along with progress in the field of immunology, which allowed detection and study of antigens from different tissues and fluids when injecting them into rabbits to promote immune response. Rubin Flocks in 1960 was the first to investigate and discover prostate-specific antigens in benign and malignant tissue. Some years later, Hara, a Japanese forensic investigator, found 'gamma seminoprotein', that he used to detect human semen in rape cases. However, his work published in Japanese did not reach the Englishspeaking scientific community. In 1970 Ablin discovered both in prostatic fluid and tissue what he called "prostate-specific antigen", but he didn't characterize or describe it. Investigators Li and Beling, and Sensabaugh, approached the current PSA, but they were limited by available technology at that time. Dr T Ming Chu led a research team on prostate cancer in New York, USA and published their results in 1979. He finally received the patent for the discovery of "human purified prostate antigen" in 1984. Due to this work, the Food and Drug Administration (FDA), in USA, approved the use of PSA for monitoring recurrence after treatment. It was later known that PSA was not prostate-specific since it was produced in other tissues and fluids, but it was recognized that it was human species-specific. Works by Papsidero and Stamey showed new indications and utilities for PSA, but it was Catalona who first used it as a marker for prostate cancer in 1991. Thanks to these advances FDA authorized in 1994 the clinical use of PSA for early detection of prostate cancer.

Salvage radiotherapy for prostate-specific antigen relapse after radical prostatectomy for prostate cancer. A single-center experience

International Nuclear Information System (INIS)

Yoshida, Takahiro; Nakayama, Masashi; Suzuki, Osamu

2011-01-01

The aim of this study was to investigate the efficacy and prognostic factors of salvage radiotherapy for prostate-specific antigen relapse after radical prostatectomy for prostate cancer at a single center in Japan. A retrospective review of the medical records of 51 patients who underwent salvage radiotherapy for prostate-specific antigen relapse after radical prostatectomy was carried out. Salvage radiotherapy was undergone for the single indication of at least two consecutive prostate-specific antigen elevations >0.1 ng/ml. Salvage radiotherapy was delivered to the prostatic bed at a total dose of 60 or 64 Gy. Late toxicity was scored according to the Common Terminology Criteria for Adverse Events 3.0. A total dose of 60 and 64 Gy were administered to 26 and 25 patients, respectively. The median prostate-specific antigen level at the initiation of radiotherapy was 0.29 ng/ml (range, 0.11-1.10 ng/ml). With a median follow-up of 57.3 months (range, 9.9-134.0 months), the prostate-specific antigen relapse-free rate at 5 years was 50.7%. Multivariate analysis using Cox's proportional hazards regression model revealed that the Gleason score at radical prostatectomy ≥8 significantly predicted prostate-specific antigen relapse after salvage radiotherapy (hazard ratio 4.531; 95% confidence interval 1.413-14.535; P=0.011). The prostate-specific antigen relapse-free rate at 5 years in the Gleason score at radical prostatectomy ≤7 and at radical prostatectomy ≥8 was 62.7 and 15.4%, respectively. Salvage radiotherapy was effective for prostate-specific antigen relapse after radical prostatectomy with tolerable toxicities in Japanese patients. A high Gleason score seemed to be a poor prognostic factor. (author)

Allopurinol reduces antigen-specific and polyclonal activation of human T cells

Directory of Open Access Journals (Sweden)

Damián ePérez-Mazliah

2012-09-01

Full Text Available Allopurinol is the most popular commercially available xanthine oxidase inhibitor and it is widely used for treatment of symptomatic hyperuricaemia, or gout. Although, several anti-inflammatory actions of allopurinol have been demonstrated in vivo and in vitro, there have been few studies on the action of allopurinol on T cells. In the current study, we have assessed the effect of allopurinol on antigen-specific and mitogen-driven activation and cytokine production in human T cells. Allopurinol markedly decreased the frequency of IFN-γ and IL-2-producing T cells, either after polyclonal or antigen-specific stimulation with Herpes Simplex virus 1, Influenza virus, tetanus toxoid and Trypanosoma cruzi-derived antigens. Allopurinol attenuated CD69 upregulation after CD3 and CD28 engagement and significantly reduced the levels of spontaneous and mitogen-induced intracellular reactive oxygen species in T cells. The diminished T cell activation and cytokine production in the presence of allopurinol support a direct action of allopurinol on human T cells, offering a potential pharmacological tool for the management of cell-mediated inflammatory diseases.

Dissection of T-cell antigen specificity in human melanoma

DEFF Research Database (Denmark)

Andersen, Rikke Sick; Albæk Thrue, Charlotte; Junker, Niels

2012-01-01

Tumor-infiltrating lymphocytes (TIL) isolated from melanoma patients and expanded in vitro by interleukin (IL)-2 treatment can elicit therapeutic response after adoptive transfer, but the antigen specificities of the T cells transferred have not been determined. By compiling all known melanoma-as...... from different fragments of resected melanoma lesions. In summary, our findings provide an initial definition of T-cell populations contributing to tumor recognition in TILs although the specificity of many tumor-reactive TILs remains undefined....

Life story chapters, specific memories and the reminiscence bump

DEFF Research Database (Denmark)

Thomsen, Dorthe Kirkegaard; Pillemer, David B.; Ivcevic, Zorana

2011-01-01

Theories of autobiographical memory posit that extended time periods (here termed chapters) and memories are organised hierarchically. If chapters organise memories and guide their recall, then chapters and memories should show similar temporal distributions over the life course. Previous research...... are over-represented at the beginning of chapters. Potential connections between chapters and the cultural life script are also examined. Adult participants first divided their life story into chapters and identified their most positive and most negative chapter. They then recalled a specific memory from...... demonstrates that positive but not negative memories show a reminiscence bump and that memories cluster at the beginning of extended time periods. The current study tested the hypotheses that (1) ages marking the beginning of positive but not negative chapters produce a bump, and that (2) specific memories...

Immunity to tumour antigens.

Science.gov (United States)

Li, Geng; Ali, Selman A; McArdle, Stephanie E B; Mian, Shahid; Ahmad, Murrium; Miles, Amanda; Rees, Robert C

2005-01-01

During the last decade, a large number of human tumour antigens have been identified. These antigens are classified as tumour-specific shared antigens, tissue-specific differentiation antigens, overexpressed antigens, tumour antigens resulting from mutations, viral antigens and fusion proteins. Antigens recognised by effectors of immune system are potential targets for antigen-specific cancer immunotherapy. However, most tumour antigens are self-proteins and are generally of low immunogenicity and the immune response elicited towards these tumour antigens is not always effective. Strategies to induce and enhance the tumour antigen-specific response are needed. This review will summarise the approaches to discovery of tumour antigens, the current status of tumour antigens, and their potential application to cancer treatment.

Is sharing specific autobiographical memories a distinct form of self-disclosure?

Science.gov (United States)

Beike, Denise R; Brandon, Nicole R; Cole, Holly E

2016-04-01

Theories of autobiographical memory posit a social function, meaning that recollecting and sharing memories of specific discrete events creates and maintains relationship intimacy. Eight studies with 1,271 participants tested whether sharing specific autobiographical memories in conversations increases feelings of closeness among conversation partners, relative to sharing other self-related information. The first 2 studies revealed that conversations in which specific autobiographical memories were shared were also accompanied by feelings of closeness among conversation partners. The next 5 studies experimentally introduced specific autobiographical memories versus general information about the self into conversations between mostly unacquainted pairs of participants. Discussing specific autobiographical memories led to greater closeness among conversation partners than discussing nonself-related topics, but no greater closeness than discussing other, more general self-related information. In the final study unacquainted pairs in whom feelings of closeness had been experimentally induced through shared humor were more likely to discuss specific autobiographical memories than unacquainted control participant pairs. We conclude that sharing specific autobiographical memories may express more than create relationship closeness, and discuss how relationship closeness may afford sharing of specific autobiographical memories by providing common ground, a social display, or a safety signal. (c) 2016 APA, all rights reserved).

Use of recombinant purified protein derivative (PPD) antigens as specific skin test for tuberculosis.

Science.gov (United States)

Stavri, Henriette; Bucurenci, Nadia; Ulea, Irina; Costache, Adriana; Popa, Loredana; Popa, Mircea Ioan

2012-11-01

Purified protein derivative (PPD) is currently the only available skin test reagent used worldwide for the diagnosis of tuberculosis (TB). The aim of this study was to develop a Mycobacterium tuberculosis specific skin test reagent, without false positive results due to Bacillus Calmette-Guerin (BCG) vaccination using recombinant antigens. Proteins in PPD IC-65 were analyzed by tandem mass spectrometry and compared to proteins in M. tuberculosis culture filtrate; 54 proteins were found in common. Top candidates MPT64, ESAT 6, and CFP 10 were overexpressed in Escherichia coli expression strains and purified as recombinant proteins. To formulate optimal immunodiagnostic PPD cocktails, the antigens were evaluated by skin testing guinea pigs sensitized with M. tuberculosis H37Rv and BCG. For single antigens and a cocktail mixture of these antigens, best results were obtained using 3 μg/0.1 ml, equivalent to 105 TU (tuberculin units). Each animal was simultaneously tested with PPD IC-65, 2 TU/0.1 ml, as reference. Reactivity of the multi-antigen cocktail was greater than that of any single antigen. The skin test results were between 34.3 and 76.6 per cent the level of reactivity compared to that of the reference when single antigens were tested and 124 per cent the level of reactivity compared to the reference for the multi-antigen cocktail. Our results showed that this specific cocktail could represent a potential candidate for a new skin diagnostic test for TB.

Using the AD12-ICT rapid-format test to detect Wuchereria bancrofti circulating antigens in comparison to Og4C3-ELISA and nucleopore membrane filtration and microscopy techniques.

Science.gov (United States)

El-Moamly, Amal Abdul-Rasheed; El-Sweify, Mohamed Aly; Hafez, Mohamad Abdul

2012-09-01

Lymphatic filariasis (LF) continues to be a major source of permanent disability and an impediment to socio-economic development in 73 countries where more than 1 billion people are at risk and over 120 millions are infected. The global drive to eliminate LF necessitates an increasing demand for valid, reliable and rapid diagnostic tests. This study aimed to assess the performance of the AD12 rapid format immunochromatographic test (ICT) to detect Wuchereria bancrofti circulating antigens, against the combined gold standard: TropBio Og4C3-ELISA (enzyme-linked immunosorbent assay) which detects circulating filarial antigen (CFA) and the nucleopore membrane filtration and microscopic examination. This prospective case-control study involved 647 asymptomatic migrant workers from filariasis-endemic countries. Of these specimens, 32 were positive for microfilaremia using the membrane filtration and microscopy, 142 positive by ELISA (of which 32 had microfilaremia), and 128 positive by the ICT (of which 31 had microfilaremia). The performance of the ICT was calculated against 32 true-positive and 90 true-negative cases. For the detection of CFA, the ICT had a sensitivity of 97% (95% confidence interval [CI] 91-103), specificity 100% (95% CI 100-100), Positive Predictive Value (PPV) 100% (95% CI 100-100), Negative Predictive Value (NPV) 99% (95% CI 97-101); and the total accuracy of the test was 99% (95% CI 98-101). The agreement between ICT and ELISA in detecting W. bancrofti antigens was excellent (kappa = 0.934; p = 0.000). In conclusion, the AD12-ICT test for the detection of W. bancrofti-CFA was sensitive and specific and comparable to the performance of ELISA. The ICT would be a useful additional test to facilitate the proposed strategies for control and elimination of LF. Because it is rapid, simple to perform, and does not require the use of special equipment, the ICT may be most appropriate in screening programs and in monitoring the possible risk of introducing

Pretreatment antigen-specific immunity and regulation - association with subsequent immune response to anti-tumor DNA vaccination.

Science.gov (United States)

Johnson, Laura E; Olson, Brian M; McNeel, Douglas G

2017-07-18

Immunotherapies have demonstrated clinical benefit for many types of cancers, however many patients do not respond, and treatment-related adverse effects can be severe. Hence many efforts are underway to identify treatment predictive biomarkers. We have reported the results of two phase I trials using a DNA vaccine encoding prostatic acid phosphatase (PAP) in patients with biochemically recurrent prostate cancer. In both trials, persistent PAP-specific Th1 immunity developed in some patients, and this was associated with favorable changes in serum PSA kinetics. In the current study, we sought to determine if measures of antigen-specific or antigen non-specific immunity were present prior to treatment, and associated with subsequent immune response, to identify possible predictive immune biomarkers. Patients who developed persistent PAP-specific, IFNγ-secreting immune responses were defined as immune "responders." The frequency of peripheral T cell and B cell lymphocytes, natural killer cells, monocytes, dendritic cells, myeloid derived suppressor cells, and regulatory T cells were assessed by flow cytometry and clinical laboratory values. PAP-specific immune responses were evaluated by cytokine secretion in vitro, and by antigen-specific suppression of delayed-type hypersensitivity to a recall antigen in an in vivo SCID mouse model. The frequency of peripheral blood cell types did not differ between the immune responder and non-responder groups. Non-responder patients tended to have higher PAP-specific IL-10 production pre-vaccination (p = 0.09). Responder patients had greater preexisting PAP-specific bystander regulatory responses that suppressed DTH to a recall antigen (p = 0.016). While our study population was small (n = 38), these results suggest that different measures of antigen-specific tolerance or regulation might help predict immunological outcome from DNA vaccination. These will be prospectively evaluated in an ongoing randomized, phase II trial.

Expression cloning of camelid nanobodies specific for Xenopus embryonic antigens.

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Keiji Itoh

Full Text Available Developmental biology relies heavily on the use of conventional antibodies, but their production and maintenance involves significant effort. Here we use an expression cloning approach to identify variable regions of llama single domain antibodies (known as nanobodies, which recognize specific embryonic antigens. A nanobody cDNA library was prepared from lymphocytes of a llama immunized with Xenopus embryo lysates. Pools of bacterially expressed cDNAs were sib-selected for the ability to produce specific staining patterns in gastrula embryos. Three different nanobodies were isolated: NbP1 and NbP3 stained yolk granules, while the reactivity of NbP7 was predominantly restricted to the cytoplasm and the cortex. The isolated nanobodies recognized specific protein bands in immunoblot analysis. A reverse proteomic approach identified NbP1 target antigen as EP45/Seryp, a serine protease inhibitor. Given the unique stability of nanobodies and the ease of their expression in diverse systems, we propose that nanobody cDNA libraries represent a promising resource for molecular markers for developmental biology.

The performance characteristics of prostate-specific antigen and prostate-specific antigen density in Chinese men.

Science.gov (United States)

Teoh, Jeremy Yc; Yuen, Steffi Kk; Tsu, James Hl; Wong, Charles Kw; Ho, Brian Sh; Ng, Ada Tl; Ma, Wai-Kit; Ho, Kwan-Lun; Yiu, Ming-Kwong

2017-01-01

We investigated the performance characteristics of prostate-specific antigen (PSA) and PSA density (PSAD) in Chinese men. All Chinese men who underwent transrectal ultrasound-guided prostate biopsy (TRUS-PB) from year 2000 to 2013 were included. The receiver operating characteristic (ROC) curves for both PSA and PSAD were analyzed. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) at different cut-off levels were calculated. A total of 2606 Chinese men were included. For the ROC, the area under curve was 0.770 for PSA (P specificity of 14.1%, PPV of 29.5%, and NPV of 86.9%; PSAD of 0.12 ng ml-1 cc-1 had sensitivity of 94.5%, specificity of 26.6%, PPV of 32.8%, and NPV of 92.7%. On multivariate logistic regression analyses, PSA cut-off at 4.5 ng ml-1 (OR 1.61, 95% CI 1.05-2.45, P= 0.029) and PSAD cut-off at 0.12 ng ml-1 cc-1 (OR 6.22, 95% CI 4.20-9.22, Pprostate cancer detection on TRUS-PB. In conclusion, the performances of PSA and PSAD at different cut-off levels in Chinese men were very different from those in Caucasians. PSA of 4.5 ng ml-1 and PSAD of 0.12 ng ml-1 cc-1 had near 95% sensitivity and were significant predictors of prostate cancer detection in Chinese men.

Effect of Heamolysis on Prostate-Specific Antigen

OpenAIRE

Sağlam, Hasan S.; Köse, Osman; Özdemir, Fatma; Adsan, Öztuğ

2012-01-01

Purpose. We have investigated the effect of haemolysis on free and total prostate-specific antigen (PSA) in daily clinical practice. Materials and Methods. Thirty-nine consecutive men were enrolled in this study. With an 18 gauge (G) needle 4 cc of blood samples were drawn from the right arm and 2 cc of it was expelled gently in a Vacutainer for regular PSA assay and the remaining was emptied into a second tube for complete haemolysis. Simultaneously 2 cc of more blood were taken with a 26 G ...

Strategy for eliciting antigen-specific CD8+ T cell-mediated immune response against a cryptic CTL epitope of merkel cell polyomavirus large T antigen

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Gomez Bianca P

2012-10-01

Full Text Available Abstract Background Merkel cell carcinoma (MCC is a relatively new addition to the expanding category of oncovirus-induced cancers. Although still comparably rare, the number of cases has risen dramatically in recent years. Further complicating this trend is that MCC is an extremely aggressive neoplasm with poor patient prognosis and limited treatment options for advanced disease. The causative agent of MCC has been identified as the merkel cell polyomavirus (MCPyV. The MCPyV-encoded large T (LT antigen is an oncoprotein that is theorized to be essential for virus-mediated tumorigenesis and is therefore, an excellent MCC antigen for the generation of antitumor immune responses. As a foreign antigen, the LT oncoprotein avoids the obstacle of immune tolerance, which normally impedes the development of antitumor immunity. Ergo, it is an excellent target for anti-MCC immunotherapy. Since tumor-specific CD8+ T cells lead to better prognosis for MCC and numerous other cancers, we have generated a DNA vaccine that is capable of eliciting LT-specific CD8+ T cells. The DNA vaccine (pcDNA3-CRT/LT encodes the LT antigen linked to a damage-associated molecular pattern, calreticulin (CRT, as it has been demonstrated that the linkage of CRT to antigens promotes the induction of antigen-specific CD8+ T cells. Results The present study shows that DNA vaccine-induced generation of LT-specific CD8+ T cells is augmented by linking CRT to the LT antigen. This is relevant since the therapeutic effects of the pcDNA3-CRT/LT DNA vaccine is mediated by LT-specific CD8+ T cells. Mice vaccinated with the DNA vaccine produced demonstrably more LT-specific CD8+ T cells. The DNA vaccine was also able to confer LT-specific CD8+ T cell-mediated protective and therapeutic effects to prolong the survival of mice with LT-expressing tumors. In the interest of determining the LT epitope which most MCC-specific CD8+ T cells recognize, we identified the amino acid sequence of the

Memory deficit in patients with schizophrenia and posttraumatic stress disorder: relational vs item-specific memory

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Jung W

2016-05-01

Full Text Available Wookyoung Jung,1 Seung-Hwan Lee1,2 1Clinical Emotions and Cognition Research Laboratory, Department of Psychiatry, Inje University, Ilsan-Paik Hospital, 2Department of Psychiatry, Inje University, Ilsan-Paik Hospital, Goyang, Korea Abstract: It has been well established that patients with schizophrenia have impairments in cognitive functioning and also that patients who experienced traumatic events suffer from cognitive deficits. Of the cognitive deficits revealed in schizophrenia or posttraumatic stress disorder (PTSD patients, the current article provides a brief review of deficit in episodic memory, which is highly predictive of patients’ quality of life and global functioning. In particular, we have focused on studies that compared relational and item-specific memory performance in schizophrenia and PTSD, because measures of relational and item-specific memory are considered the most promising constructs for immediate tangible development of clinical trial paradigm. The behavioral findings of schizophrenia are based on the tasks developed by the Cognitive Neuroscience Treatment Research to Improve Cognition in Schizophrenia (CNTRICS initiative and the Cognitive Neuroscience Test Reliability and Clinical Applications for Schizophrenia (CNTRACS Consortium. The findings we reviewed consistently showed that schizophrenia and PTSD are closely associated with more severe impairments in relational memory compared to item-specific memory. Candidate brain regions involved in relational memory impairment in schizophrenia and PTSD are also discussed. Keywords: schizophrenia, posttraumatic stress disorder, episodic memory deficit, relational memory, item-specific memory, prefrontal cortex, hippocampus

Prostate specific antigen - brief update on its clinical use | Heyns ...

African Journals Online (AJOL)

Prostate specific antigen - brief update on its clinical use. ... (45 years in those with a family history of prostate cancer and – possibly – African men); ... PSA doubling time (the period it takes for the PSA to double) correlates with the prognosis ...

Assessing drivers of the IgG4 antibody reactivity to recombinant antigen Bm14 in Wuchereria bancrofti endemic populations in East Africa

DEFF Research Database (Denmark)

Hansen, Johanne Damgaard; Meyrowitsch, Dan W.; Rwegoshora, Rwehumbiza T.

2016-01-01

to the recombinant filarial antigen Bm14 in Wuchereria bancrofti endemic populations in East Africa. Sera collected during previous studies from 395 well characterized individuals with regard to age, sex, mf, CFA, household vector biting and household exposure to infective filarial larvae were tested for IgG4......A high proportion of the human population in lymphatic filariasis (LF) endemic areas is positive for filarial specific IgG4 antibodies, including many individuals without microfilariae (mf; circulating larvae in the human blood) or circulating filarial antigens (CFA; marker of adult worm infection...

The Hamster Model for Identification of Specific Antigens of Taenia solium Tapeworms

Science.gov (United States)

Ochoa-Sánchez, Alicia; Jiménez, Lucía; Landa, Abraham

2011-01-01

Humans acquire taeniasis by ingesting pork meat infected with Taenia solium cysticerci, which are the only definitive hosts of the adult stage (tapeworm) and responsible for transmitting the human and porcine cysticercosis. Hence, detection of human tapeworm carriers is a key element in the development of viable strategies to control the disease. This paper presents the identification of specific antigens using sera from hamsters infected with T. solium tapeworms analyzed by western blot assay with crude extracts (CEs) and excretion-secretion antigens (E/S Ag) obtained from T. solium cysticerci and tapeworms and extracts from other helminthes as controls. The hamster sera infected with T. solium tapeworms recognized specific bands of 72, 48, 36, and 24 kDa, in percentages of 81, 81, 90, and 88%, respectively, using the T. solium tapeworms E/S Ag. The antigens recognized by these hamster sera could be candidates to improve diagnosis of human T. solium taeniasis. PMID:22253530

The Hamster Model for Identification of Specific Antigens of Taenia solium Tapeworms

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Alicia Ochoa-Sánchez

2011-01-01

Full Text Available Humans acquire taeniasis by ingesting pork meat infected with Taenia solium cysticerci, which are the only definitive hosts of the adult stage (tapeworm and responsible for transmitting the human and porcine cysticercosis. Hence, detection of human tapeworm carriers is a key element in the development of viable strategies to control the disease. This paper presents the identification of specific antigens using sera from hamsters infected with T. solium tapeworms analyzed by western blot assay with crude extracts (CEs and excretion-secretion antigens (E/S Ag obtained from T. solium cysticerci and tapeworms and extracts from other helminthes as controls. The hamster sera infected with T. solium tapeworms recognized specific bands of 72, 48, 36, and 24 kDa, in percentages of 81, 81, 90, and 88%, respectively, using the T. solium tapeworms E/S Ag. The antigens recognized by these hamster sera could be candidates to improve diagnosis of human T. solium taeniasis.

Human Tregs Made Antigen Specific by Gene Modification: The Power to Treat Autoimmunity and Antidrug Antibodies with Precision

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Patrick R. Adair

2017-09-01

Full Text Available Human regulatory CD4+ T cells (Tregs are potent immunosuppressive lymphocytes responsible for immune tolerance and homeostasis. Since the seminal reports identifying Tregs, vast research has been channeled into understanding their genesis, signature molecular markers, mechanisms of suppression, and role in disease. This research has opened the doors for Tregs as a potential therapeutic for diseases and disorders such as multiple sclerosis, type I diabetes, transplantation, and immune responses to protein therapeutics, like factor VIII. Seminal clinical trials have used polyclonal Tregs, but the frequency of antigen-specific Tregs among polyclonal populations is low, and polyclonal Tregs may risk non-specific immunosuppression. Antigen-specific Treg therapy, which uses genetically modified Tregs expressing receptors specific for target antigens, greatly mitigates this risk. Building on the principles of T-cell receptor cloning, chimeric antigen receptors (CARs, and a novel CAR derivative, called B-cell antibody receptors, our lab has developed different types of antigen-specific Tregs. This review discusses the current research and optimization of gene-modified antigen-specific human Tregs in our lab in several disease models. The preparations and considerations for clinical use of such Tregs also are discussed.

Activated human nasal epithelial cells modulate specific antibody response against bacterial or viral antigens.

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Chiou-Yueh Yeh

Full Text Available Nasal mucosa is an immune responsive organ evidenced by eliciting both specific local secretory IgA and systemic IgG antibody responses with intra-nasal administration of antigens. Nevertheless, the role of nasal epithelial cells in modulating such responses is unclear. Human nasal epithelial cells (hNECs obtained from sinus mucosa of patients with chronic rhinosinusitis were cultured in vitro and firstly were stimulated by Lactococcus lactis bacterium-like particles (BLPs in order to examine their role on antibody production. Secondly, both antigens of immunodominant protein IDG60 from oral Streptococcus mutans and hemagglutinin (HA from influenza virus were tested to evaluate the specific antibody response. Stimulated hNECs by BLPs exhibited a significant increase in the production of interleukin-6 (IL-6, and thymic stromal lymphopoietin (TSLP. Conditioned medium of stimulated hNECs has effects on enhancing the proliferation of CD4+ T cells together with interferon-γ and IL-5 production, increasing the costimulatory molecules on dendritic cells and augmenting the production of IDG60 specific IgA, HA specific IgG, IgA by human peripheral blood lymphocytes. Such production of antigen specific IgG and IgA is significantly counteracted in the presence of IL-6 and TSLP neutralizing antibodies. In conclusion, properly stimulated hNECs may impart immuno-modulatory effects on the antigen-specific antibody response at least through the production of IL-6 and TSLP.

New developments in the standardization of total prostate-specific antigen.

Science.gov (United States)

Blijenberg, B G; Storm, B N; Van Zelst, B D; Kruger, A E; Schröder, F H

1999-11-01

Analytical evaluation of the calibration of three recently launched assays for the measurement of total prostate-specific antigen, i.e., IMx Total PSA (Abbott), Elecsys PSA (Roche), and IMMULITE 3rd Generation PSA (DPC). For accuracy assessment two reference materials were applied namely, Stanford 90:10 PSA Calibrator and Certified Reference Material 613 Prostate-Specific Antigen. Dilutions of these preparations were analyzed with all assays. In addition, clinical specimens from known prostate cancer or benign prostate hyperplasia patients and samples taken from an ongoing prostate cancer screening study were used for comparison. Application of the Stanford Calibrator revealed results well within 10% of the calculated values for all assays. Regarding the CRM Calibrator only the IMx Total PSA proved to approach the line of identity. The IMMULITE results differed about 40% and the Elecsys about 18% from the calculated values. The comparison with clinical specimens showed statistically different results for the combination IMMULITE-IMx and for IMMULITE-Elecsys. The regression lines for both collections were: y(IMx) = 0.86x(IMMULITE) +0.12 (n = 104, r = 0.970, Sy/x = 0.883 microg/L) and y(Elecsys) = 0.98x(IMMULITE) +0.38 (n = 97, r = 0.976, Sy/x = 0.733 microg/L). In the lower measuring range (PSA differences were less pronounced. In analytical sense a difference was found for both reference preparations in the assays studied. Clinically, despite improvements in methodology, results for total prostate-specific antigen are still not interchangeable. The possible consequences need to be elaborated.

Antibody-antigen-adjuvant conjugates enable co-delivery of antigen and adjuvant to dendritic cells in cis but only have partial targeting specificity.

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Martin Kreutz

Full Text Available Antibody-antigen conjugates, which promote antigen-presentation by dendritic cells (DC by means of targeted delivery of antigen to particular DC subsets, represent a powerful vaccination approach. To ensure immunity rather than tolerance induction the co-administration of a suitable adjuvant is paramount. However, co-administration of unlinked adjuvant cannot ensure that all cells targeted by the antibody conjugates are appropriately activated. Furthermore, antigen-presenting cells (APC that do not present the desired antigen are equally strongly activated and could prime undesired responses against self-antigens. We, therefore, were interested in exploring targeted co-delivery of antigen and adjuvant in cis in form of antibody-antigen-adjuvant conjugates for the induction of anti-tumour immunity. In this study, we report on the assembly and characterization of conjugates consisting of DEC205-specific antibody, the model antigen ovalbumin (OVA and CpG oligodeoxynucleotides (ODN. We show that such conjugates are more potent at inducing cytotoxic T lymphocyte (CTL responses than control conjugates mixed with soluble CpG. However, our study also reveals that the nucleic acid moiety of such antibody-antigen-adjuvant conjugates alters their binding and uptake and allows delivery of the antigen and the adjuvant to cells partially independently of DEC205. Nevertheless, antibody-antigen-adjuvant conjugates are superior to antibody-free antigen-adjuvant conjugates in priming CTL responses and efficiently induce anti-tumour immunity in the murine B16 pseudo-metastasis model. A better understanding of the role of the antibody moiety is required to inform future conjugate vaccination strategies for efficient induction of anti-tumour responses.

SENSITIVITY AND SPECIFICITY OF URINARY BLADDER CANCER ANTIGEN FOR DIAGNOSIS OF BLADDER TUMOR;A COMPARATIVE STUDY WITH URINARY CYTOLOGY

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K. Radkhah

2005-06-01

Full Text Available Cystoscopy and urinary cytology are currently the basis for diagnosis and ‎follow-up of bladder tumors. Research to find a sensitive and specific tumor ‎marker for diagnosis of bladder tumor is actively underway, however, due to low sensitivity ‎and high cost of cytology. This cross-sectional study was performed in 65 patients to evaluate whether urinary bladder ‎cancer (UBC antigen level can predict the presence of active bladder tumor. In patients with ‎inactive tumor, UBC antigen level was determined in addition to standard cystoscopy ‎and cytology for follow-up. Patients with active tumor were ‎subjected to standard treatment and UBC antigen level determination. UBC antigen ‎ levels were measured by ELISA, using monoclonal antibodies ‎specific for UBC antigen. As a control group, UBC antigen level ‎was also determined in 65 persons who had been referred for urinalysis for other reasons. ‎UBC antigen level more than 1 μg/L which was regarded as ‎positive was found in 49.4% of the patients. In control group, 96.9% had UBC antigen < 1μg/L‎. Mean UBC antigen level in patients was ‎3.77 μg/L while it was 0.508 μg/L in controls (P < 0.0001. Sensitivity of ‎UBC antigen was 53.3% and its specificity was 40%. Sensitivity and specificity of urinary cytology was 17.3% and 88.2%, respectively. This difference was statistically ‎significant (P < 0.001. UBC antigen is more sensitive than urinary cytology, although cytology still ‎retains its priority in specificity. It is not yet recommended to replace UBC antigen for ‎cytology due to its low specificity and not favorable sensitivity.

Expression of the Gastrin-Releasing Peptide Receptor, the Prostate Stem Cell Antigen and the Prostate-Specific Membrane Antigen in Lymph Node and Bone Metastases of Prostate Cancer

NARCIS (Netherlands)

Ananias, Hildo J. K.; van den Heuvel, Marius C.; Helfrich, Wijnand; de Jong, Igle J.

2009-01-01

OBJECTIVE. Cell membrane antigens like the gastrin-releasing peptide receptor (GRPR), the prostate stem cell antigen (PSCA), and the prostate-specific membrane antigen (PSMA), expressed in prostate cancer, are attractive targets for new therapeutic and diagnostic applications. Therefore, we

Rapid analysis of rearranged kappa light chain genes of circulating polysaccharide-specific B lymphocytes by means of immunomagnetic beads and the polymerase chain reaction

DEFF Research Database (Denmark)

Hougs, L; Barington, T; Madsen, HO

1993-01-01

reaction (PCR) using in addition a degenerate kappa light chain signal peptide region primer. The PCR product was cloned into the M13mp18 phage. The cloning efficiency was 100-600 clones/ml of blood. Of the 86 clones sequenced, 90% represented rearranged kappa light chain genes from different antibody...... of the B lymphocytes activated in vivo. Here, we present a method for rapid analysis of the rearranged kappa light chain genes used by human circulating antigen-specific B lymphocytes. After vaccination with Haemophilus influenzae type b capsular polysaccharide (HibCP) conjugated with protein, the Hib...

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

International Nuclear Information System (INIS)

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

2011-01-01

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

Antigen modulation of the immune response. III. Evaluation of the hypothetical short-lived memory cell

International Nuclear Information System (INIS)

Feldbush, T.L.; Lande, I.; Bryan, B.; O'Neill, E.

1974-01-01

The putative short-lived memory cells, whose existence has been suggested by the results of secondary adoptive transfer experiments, were investigated. On the basis of the following evidences we have concluded that the short-lived memory cell is probably an artifact of the adoptive transfer technique: when immune thoracic duct lymphocytes, known to consist predominantly of long-lived memory cells, were transferred to irradiated recipients and challenged at various times after transfer, approximately 80 to 90 percent of the initial response was absent by Day 14 challenge; preirradiating adoptive recipients with increasing dose of x-irradiation tended to lengthen the observed half life of memory cells; single or multiple treatments of immune donors with 0.3 mg Vinblastin before transfer resulted in neither a depression of the initial secondary response nor an alteration in the rate of decline of the memory potential; reconstitution of irradiated hosts with normal spleen cells one day before transfer of memory cells and challenge resulted in inhibition of the adoptive secondary response; and the transfer of memory cells to antigen free intermediate hosts, in which they were allowed to reside for one day or fourteen days before transfer to irradiated recipients, resulted in only a slight decline in their capacity to respond. We propose that the rapid decline of memory potential in adoptive recipients challenged at various times after transfer is due to modulating effects by the hosts as it recovers from irradiation. These effects may be the result of cell crowding or the loss of irradiation-produced stimulatory factors. The relevance of these findings to adoptive transfer systems in general and the secondary response of intact animals is discussed

Professional memory CD4+ T lymphocytes preferentially reside and rest in the bone marrow.

Science.gov (United States)

Tokoyoda, Koji; Zehentmeier, Sandra; Hegazy, Ahmed N; Albrecht, Inka; Grün, Joachim R; Löhning, Max; Radbruch, Andreas

2009-05-01

CD4(+) T lymphocytes are key to immunological memory. Here we show that in the memory phase of specific immune responses, most of the memory CD4(+) T lymphocytes had relocated into the bone marrow (BM) within 3-8 weeks after their generation-a process involving integrin alpha2. Antigen-specific memory CD4(+) T lymphocytes highly expressed Ly-6C, unlike most splenic CD44(hi)CD62L(-) CD4(+) T lymphocytes. In adult mice, more than 80% of Ly-6C(hi)CD44(hi)CD62L(-) memory CD4(+) T lymphocytes were in the BM. In the BM, they associated to IL-7-expressing VCAM-1(+) stroma cells. Gene expression and proliferation were downregulated, indicating a resting state. Upon challenge with antigen, they rapidly expressed cytokines and CD154 and efficiently induced the production of high-affinity antibodies by B lymphocytes. Thus, in the memory phase of immunity, memory helper T cells are maintained in BM as resting but highly reactive cells in survival niches defined by IL-7-expressing stroma cells.

Prostate specific antigen and its clinical application

International Nuclear Information System (INIS)

Xu Yang

2000-01-01

Prostate-Specific Antigen (PSA), a serine proteases, is a glycoprotein consisting of a single polypeptide chain. Secreted exclusively by epithelial cells of the prostate gland, PSA is found largely in seminal plasma. Only a small amount of PSA can be found in normal serum. Serum PSA levels are found to be, considerably increased in prostate cancer patients. A number of studies on PSA have made great achievement on its biochemistry, analytical method and clinical application. PSA as one of the most important tumor marker, is used to help diagnosis and monitor the therapeutic efficacy of prostate cancer

Reduced specificity of autobiographical memories in young people with tic disorders.

Science.gov (United States)

Pile, Victoria; Robinson, Sally; Roberts, Elystan; Topor, Marta; Hedderly, Tammy; Lau, Jennifer Y F

2018-05-01

Depression is common in Tourette syndrome and Chronic Tic Disorders (TS/CTD) and contributes to significant impairment. The specificity of autobiographical memories is implicated in an individual's sense of self and their daily functioning but also in the onset and development of depression in the general population. Here, we examined whether memory specificity is reduced in young people with TS/CTD, relative to control participants, and whether memory specificity is associated with depression. Thirty young people with TS/CTD (14 females; age: x̅ = 11.31; SD = 1.66; 87% White British) and twenty-six (12 females; age: x̅ = 11.23; SD = 2.43; 77% White British) control participants completed the study. Participants completed the Autobiographical Memory Task, which asks participants to respond with a specific memory to cue words, and a questionnaire measure of depressive symptoms. There was no significant difference between the two groups in terms of age, gender, ethnicity, IQ and depressive symptomatology. Young people with TS/CTD had less specific autobiographical memories than their peers (p < 0.001, r = 0.49). Across both groups, increased memory specificity for positive cue words was associated with reduced depressive symptomatology (p < 0.001, R 2  = 0.51). Our findings indicate that autobiographical memory in young people with TS is characterised by a lack of specificity and, as with neurotypical peers, reduced memory specificity for positive words is associated with depressive symptoms. Autobiographical memory specificity could be an important factor in understanding mood symptoms that characterise young people with TS/CTD and may be an important cognitive target to reduce the development of depression in young people with TS/CTD. Copyright © 2018 Elsevier Inc. All rights reserved.

Encoding specificity manipulations do affect retrieval from memory.

Science.gov (United States)

Zeelenberg, René

2005-05-01

In a recent article, P.A. Higham (2002) [Strong cues are not necessarily weak: Thomson and Tulving (1970) and the encoding specificity principle revisited. Memory &Cognition, 30, 67-80] proposed a new way to analyze cued recall performance in terms of three separable aspects of memory (retrieval, monitoring, and report bias) by comparing performance under both free-report and forced-report instructions. He used this method to derive estimates of these aspects of memory in an encoding specificity experiment similar to that reported by D.M. Thomson and E. Tulving (1970) [Associative encoding and retrieval: weak and strong cues. Journal of Experimental Psychology, 86, 255-262]. Under forced-report instructions, the encoding specificity manipulation did not affect performance. Higham concluded that the manipulation affected monitoring and report bias, but not retrieval. I argue that this interpretation of the results is problematic because the Thomson and Tulving paradigm is confounded, and show in three experiments using a more appropriate design that encoding specificity manipulations do affect performance in forced-report cued recall. Because in Higham's framework forced-report performance provides a measure of retrieval that is uncontaminated by monitoring and report bias it is concluded that encoding specificity manipulations do affect retrieval from memory.

Levels of processing and language modality specificity in working memory.

Science.gov (United States)

Rudner, Mary; Karlsson, Thomas; Gunnarsson, Johan; Rönnberg, Jerker

2013-03-01

Neural networks underpinning working memory demonstrate sign language specific components possibly related to differences in temporary storage mechanisms. A processing approach to memory systems suggests that the organisation of memory storage is related to type of memory processing as well. In the present study, we investigated for the first time semantic, phonological and orthographic processing in working memory for sign- and speech-based language. During fMRI we administered a picture-based 2-back working memory task with Semantic, Phonological, Orthographic and Baseline conditions to 11 deaf signers and 20 hearing non-signers. Behavioural data showed poorer and slower performance for both groups in Phonological and Orthographic conditions than in the Semantic condition, in line with depth-of-processing theory. An exclusive masking procedure revealed distinct sign-specific neural networks supporting working memory components at all three levels of processing. The overall pattern of sign-specific activations may reflect a relative intermodality difference in the relationship between phonology and semantics influencing working memory storage and processing. Copyright © 2012 Elsevier Ltd. All rights reserved.

Characterization of Specific Immune Responses to Different Aspergillus Antigens during the Course of Invasive Aspergillosis in Hematologic Patients

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Beauvais, Anne; Beau, Remi; Candoni, Anna; Maertens, Johan; Rossi, Giulio; Morselli, Monica; Zanetti, Eleonora; Quadrelli, Chiara; Codeluppi, Mauro; Guaraldi, Giovanni; Pagano, Livio; Caira, Morena; Giovane, Cinzia Del; Maccaferri, Monica; Stefani, Alessandro; Morandi, Uliano; Tazzioli, Giovanni; Girardis, Massimo; Delia, Mario; Specchia, Giorgina; Longo, Giuseppe; Marasca, Roberto; Narni, Franco; Merli, Francesco; Imovilli, Annalisa; Apolone, Giovanni; Carvalho, Agostinho; Comoli, Patrizia; Romani, Luigina; Latgè, Jean Paul; Luppi, Mario

2013-01-01

Several studies in mouse model of invasive aspergillosis (IA) and in healthy donors have shown that different Aspergillus antigens may stimulate different adaptive immune responses. However, the occurrence of Aspergillus-specific T cells have not yet been reported in patients with the disease. In patients with IA, we have investigated during the infection: a) whether and how specific T-cell responses to different Aspergillus antigens occur and develop; b) which antigens elicit the highest frequencies of protective immune responses and, c) whether such protective T cells could be expanded ex-vivo. Forty hematologic patients have been studied, including 22 patients with IA and 18 controls. Specific T cells producing IL-10, IFN-γ, IL-4 and IL-17A have been characterized through enzyme linked immunospot and cytokine secretion assays on 88 peripheral blood (PB) samples, by using the following recombinant antigens: GEL1p, CRF1p, PEP1p, SOD1p, α1–3glucan, β1–3glucan, galactomannan. Specific T cells were expanded through short term culture. Aspergillus-specific T cells producing non-protective interleukin-10 (IL-10) and protective interferon-gamma (IFN-γ) have been detected to all the antigens only in IA patients. Lower numbers of specific T cells producing IL-4 and IL-17A have also been shown. Protective T cells targeted predominantly Aspergillus cell wall antigens, tended to increase during the IA course and to be associated with a better clinical outcome. Aspergillus-specific T cells could be successfully generated from the PB of 8 out of 8 patients with IA and included cytotoxic subsets able to lyse Aspergillus hyphae. Aspergillus specific T-cell responses contribute to the clearance of the pathogen in immunosuppressed patients with IA and Aspergillus cell wall antigens are those mainly targeted by protective immune responses. Cytotoxic specific T cells can be expanded from immunosuppressed patients even during the infection by using the above mentioned

ELISA with double antigen sandwich for screening specific serum anti-TP antibody in blood donors

International Nuclear Information System (INIS)

Wang Yiqing; Shi Zhixu

2002-01-01

Objective: To select a sensitive and specific laboratory examination suitable for screening serum anti-TP antibody in blood donors. Methods: The serum anti-TP antibody in 11271 blood donors were detected using ELISA with double antigen sandwich and the outcomes were compared with those using RPR assay. The conflicting specimen were confirmed by repeating the test with TPHA assay. Results: The positive rates of serum anti-TP antibody by ELISA with double antigen sandwich and RPR was 0.36% (41/11271) and 0.26% (29/11271), respectively. The coincidence of the detecting outcomes by ELISA with double antigen sandwich and RPR with TPHA was 97.5% (40/41) and 63.41%(26/41) respectively. Conclusion: Compared with RPR assay, ELISA with double antigen sandwich has higher sensibility and specificity for screening serum anti-TP antibody in blood donors

Toward low-cost affinity reagents: lyophilized yeast-scFv probes specific for pathogen antigens.

Directory of Open Access Journals (Sweden)

Sean A Gray

Full Text Available The generation of affinity reagents, usually monoclonal antibodies, remains a critical bottleneck in biomedical research and diagnostic test development. Recombinant antibody-like proteins such as scFv have yet to replace traditional monoclonal antibodies in antigen detection applications, in large part because of poor performance of scFv in solution. To address this limitation, we have developed assays that use whole yeast cells expressing scFv on their surfaces (yeast-scFv in place of soluble purified scFv or traditional monoclonal antibodies. In this study, a nonimmune library of human scFv displayed on the surfaces of yeast cells was screened for clones that bind to recombinant cyst proteins of Entamoeba histolytica, an enteric pathogen of humans. Selected yeast-scFv clones were stabilized by lyophilization and used in detection assay formats in which the yeast-scFv served as solid support-bound monoclonal antibodies. Specific binding of antigen to the yeast-scFv was detected by staining with rabbit polyclonal antibodies. In flow cytometry-based assays, lyophilized yeast-scFv reagents retained full binding activity and specificity for their cognate antigens after 4 weeks of storage at room temperature in the absence of desiccants or stabilizers. Because flow cytometry is not available to all potential assay users, an immunofluorescence assay was also developed that detects antigen with similar sensitivity and specificity. Antigen-specific whole-cell yeast-scFv reagents can be selected from nonimmune libraries in 2-3 weeks, produced in vast quantities, and packaged in lyophilized form for extended shelf life. Lyophilized yeast-scFv show promise as low cost, renewable alternatives to monoclonal antibodies for diagnosis and research.

Development of a new in vivo kit for detection of prostate specific antigen in human serum using immunoradiometric assay method

International Nuclear Information System (INIS)

Babaei, M. H.; Behradkia, P.; Shafii, M.; Movla, M.; Forutan, H.; Najafi, R.

2006-01-01

Prostate is a leading site for the cancer incidence, accounted for 31.0% of new cancer cases in men. Prostate-specific antigen is widely used in the detection and monitoring of the prostate cancer. Currently, immunoassay is used to detect Prostate-specific antigen in human serum. This technique is based on the interaction between antibody and antigen. The varied immunoassay formats and equipment to run the assays allow the users to measure the analytes rapidly, with the flexibility to run a small or a large number of samples. Among different immunoassay methods, immunoradiometric assay is a more sensitive and valuable detection approach. This study has been made in 4 parts: (1) purification of Prostate-specific antigen from seminal fluid; (2) preparation of hybridoma cells which secrete monoclonal antibody (mAb) against Prostate-specific antigen , (3) selection of pair monoclonal antibody among those antibodies, and finally (4) design of an immunoradiometric assay kit and it's quality control . The results of this study were: (1) obtaining a huge amount of Prostate-specific antigen as semi-purified and purified, that is a valuable material for preparation of standard kits; (2) preparation of 8 kinds of monoclonal antibodies; (3) finding 4 pairs of monoclonal antibodies which react with different epitopes on Prostate-specific antigen molecule; and (4) preparation of immunoradiometric assay kit for measuring Prostate-specific antigen concentration in human serum

An Evaluation of Usefulness of Prostate Specific Antigen and Digital ...

African Journals Online (AJOL)

Objective: To evaluate the usefulness of prostate specific antigen (PSA) and digital rectal examination (DRE) in the diagnosis of cancer of the prostate (CaP) amongst unscreened patients. Patients, Materials ans Methods: A prospective study168 unscreened men who were referred for evaluation for CaP. They all had a ...

The (gradual) rise of memory inflation.

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Klenerman, Paul

2018-05-01

Memory inflation, as a term, has been used for 15 years now to describe the longitudinal development of stable, expanded CD8 + T memory pools with a distinct phenotype and functional profile which emerge in specific infection and vaccine settings. These settings have in common the persistence of antigen, especially cytomegalovirus infection but also more recently adenoviral vector vaccination. However, in contrast to chronic infections which lead to "exhaustion" the repeated antigen encounters experienced by CD8 + T cells lead to development of a robust T-cell population structure which maintains functionality and size. In this review, I will discuss how the ideas around this form of memory have evolved over time and some new models which can help explain how these populations are induced and sustained. These models are relevant to immunity against persistent viruses, to novel vaccine strategies and to concepts about aging. © 2018 The Author. Immunological Reviews Published by John Wiley & Sons Ltd.

Purification and analyses of the specificity of two putative diagnostic antigens for larval cyathostomin infection in horses.

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Dowdall, S M J; Proudman, C J; Love, S; Klei, T R; Matthews, J B

2003-12-01

Cyathostomins are important equine gastrointestinal parasites. Mass emergence of mucosal stage larvae causes a potentially fatal colitis. Mucosal stages are undetectable non-invasively. An assay that would estimate mucosal larval stage infection would greatly assist in treatment, control and prognosis. Previously, we identified two putative diagnostic antigens (20 and 25 kDa) in somatic larval preparations. Here, we describe their purification and antigen-specific IgG(T) responses to them. Western blots confirmed the purity of the antigens and showed that epitopes in the 20 kDa complex were specific to larval cyathostomins. No cross-reactive antigens appeared to be present in Parascaris equorum or Strongyloides westeri species. Low levels of cross-reactivity were observed in Strongylus edentatus and Strongylus vulgaris species. Use of purified antigens greatly reduced background binding in equine sera. These results indicate that both antigen complexes may be of use in a diagnostic assay.

Prostate-specific membrane antigen-directed nanoparticle targeting for extreme nearfield ablation of prostate cancer cells.

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Lee, Seung S; Roche, Philip Jr; Giannopoulos, Paresa N; Mitmaker, Elliot J; Tamilia, Michael; Paliouras, Miltiadis; Trifiro, Mark A

2017-03-01

Almost all biological therapeutic interventions cannot overcome neoplastic heterogeneity. Physical ablation therapy is immune to tumor heterogeneity, but nearby tissue damage is the limiting factor in delivering lethal doses. Multi-walled carbon nanotubes offer a number of unique properties: chemical stability, photonic properties including efficient light absorption, thermal conductivity, and extensive surface area availability for covalent chemical ligation. When combined together with a targeting moiety such as an antibody or small molecule, one can deliver highly localized temperature increases and cause extensive cellular damage. We have functionalized multi-walled carbon nanotubes by conjugating an antibody against prostate-specific membrane antigen. In our in vitro studies using prostate-specific membrane antigen-positive LNCaP prostate cancer cells, we have effectively demonstrated cell ablation of >80% with a single 30-s exposure to a 2.7-W, 532-nm laser for the first time without bulk heating. We also confirmed the specificity and selectivity of prostate-specific membrane antigen targeting by assessing prostate-specific membrane antigen-null PC3 cell lines under the same conditions (<10% cell ablation). This suggests that we can achieve an extreme nearfield cell ablation effect, thus restricting potential tissue damage when transferred to in vivo clinical applications. Developing this new platform will introduce novel approaches toward current therapeutic modalities and will usher in a new age of effective cancer treatment squarely addressing tumoral heterogeneity.

A critical examination of the numerology of antigen-binding cells: evidence for multiple receptor specificities on single cells.

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Miller, A

1977-01-01

The data available from other laboratories as well as our own on the frequency of cells recognizing major histocompatibility antigens or conventional protein and hapten antigens is critically evaluated. The frequency of specific binding for a large number of antigens is sufficiently high to support the idea that at least part of the antigen-binding cell population must have multiple specificities. Our results suggest that these multiple specific cells result from single cells synthesizing and displaying as many as 50-100 species of receptor, each at a frequency of 10(4) per cell. A model involving gene expansion of constant-region genes is suggested and some auxilliary evidence consistent with such C-gene expansion is presented.

Stimulus-specific variability in color working memory with delayed estimation.

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Bae, Gi-Yeul; Olkkonen, Maria; Allred, Sarah R; Wilson, Colin; Flombaum, Jonathan I

2014-04-08

Working memory for color has been the central focus in an ongoing debate concerning the structure and limits of visual working memory. Within this area, the delayed estimation task has played a key role. An implicit assumption in color working memory research generally, and delayed estimation in particular, is that the fidelity of memory does not depend on color value (and, relatedly, that experimental colors have been sampled homogeneously with respect to discriminability). This assumption is reflected in the common practice of collapsing across trials with different target colors when estimating memory precision and other model parameters. Here we investigated whether or not this assumption is secure. To do so, we conducted delayed estimation experiments following standard practice with a memory load of one. We discovered that different target colors evoked response distributions that differed widely in dispersion and that these stimulus-specific response properties were correlated across observers. Subsequent experiments demonstrated that stimulus-specific responses persist under higher memory loads and that at least part of the specificity arises in perception and is eventually propagated to working memory. Posthoc stimulus measurement revealed that rendered stimuli differed from nominal stimuli in both chromaticity and luminance. We discuss the implications of these deviations for both our results and those from other working memory studies.

Chemiluminescence immunoassay for prostate-specific antigen

International Nuclear Information System (INIS)

Zhang Xuefeng; Liu Yibing; Jia Juanjuan; Xu Wenge; Li Ziying; Chen Yongli; Han Shiquan

2008-01-01

The chemiluminescence immunoassay (CLIA) for serum total prostate-specific antigen (T-PSA) was developed. The reaction of luminol with hydrogen peroxide was introduced into this chemiluminescence system. The detection limit is established as 0.12 μg/L (n=10, mean of zero standard + 2SD) and the analytical recovery of PSA is 83.8%-118.7%. The intra-assay and inter-assay CVs vary from 4.4%-5.0% and 6.2%-11.7%, respectively. The experimental correlation coefficient of dilution is found to be 0.999. Compared with immunoradiometric assay (IRMA) kits, the correlative equation is y=1.07x+0.68, and correlation coefficient r=0.97. The standard range for the method is 1.5-80 μg/L, and it presents good linearity. (authors)

Clinical use and primary evaluation of tumor marker-free prostate specific antigen

International Nuclear Information System (INIS)

Wu Junyuan; Gao Xiuying; Kong Linghua; Su Ping; Guo Xinrong

2002-01-01

Free-prostate specific antigen (fPSA)/total prostate specific antigen (tPSA) ratio was evaluated in clinical utility. Serum tPSA and fPSA level were measured by electro-chemo-luminescence (ECL) immunoassay and fPSA/tPSA ratio was calculated. Samples were drawn from 38 patients with Pca, 68 patients with BPH and 43 health men. Results showed serum tPSA > 4.0 μg/L as only cut off for diagnosis Pca, sensitivity and specificity of fPSA/tPSA ratio were 84.2%, 75.0% respectively. But fPSA/tPSA ratio 20.0 μg/L; they were 93.6%, 89.9% when serum tPSA was 2-20 μg/L. fPSA/tPSA ratio may greatly raised accurate rate for diagnosis prostate cancer when tPSA level between 2-20 μg/L and no value to other patients

A novel and effective cancer immunotherapy mouse model using antigen-specific B cells selected in vitro.

Directory of Open Access Journals (Sweden)

Tatsuya Moutai

Full Text Available Immunotherapies such as adoptive transfer of T cells or natural killer cells, or monoclonal antibody (MoAb treatment have recently been recognized as effective means to treat cancer patients. However, adoptive transfer of B cells or plasma cells producing tumor-specific antibodies has not been applied as a therapy because long-term culture and selective expansion of antigen-specific B cells has been technically very difficult. Here, we describe a novel cancer immunotherapy that uses B-cell adoptive transfer. We demonstrate that germinal-center-like B cells (iGB cells induced in vitro from mouse naïve B cells become plasma cells and produce IgG antibodies for more than a month in the bone marrow of non-irradiated recipient mice. When transferred into mice, iGB cells producing antibody against a surrogate tumor antigen suppressed lung metastasis and growth of mouse melanoma cells expressing the same antigen and prolonged survival of the recipients. In addition, we have developed a novel culture system called FAIS to selectively expand antigen-specific iGB cells utilizing the fact that iGB cells are sensitive to Fas-induced cell death unless their antigen receptors are ligated by membrane-bound antigens. The selected iGB cells efficiently suppressed lung metastasis of melanoma cells in the adoptive immunotherapy model. As human blood B cells can be propagated as iGB cells using culture conditions similar to the mouse iGB cell cultures, our data suggest that it will be possible to treat cancer-bearing patients by the adoptive transfer of cancer-antigen-specific iGB cells selected in vitro. This new adoptive immunotherapy should be an alternative to the laborious development of MoAb drugs against cancers for which no effective treatments currently exist.

Short report: Influence of culture and trauma history on autobiographical memory specificity.

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Humphries, Clare; Jobson, Laura

2012-01-01

This study investigated the influence of culture and trauma history on autobiographical memory specificity. Chinese international and British undergraduate university students (N=64) completed the autobiographical memory test, Hopkins symptom checklist-25, twenty statements test, trauma history questionnaire, and impact of events scale-revised. The results indicated that the British group provided significantly more specific memories than the Chinese group. The high trauma exposure group provided significantly fewer specific autobiographical memories than the low trauma exposure group. The interaction was not significant. The findings suggest that even in cultures where specificity is not as evident in autobiographical remembering style, trauma exposure appears to exert similar influence on autobiographical memory specificity.

Tissue concentrations of prostate-specific antigen in prostatic carcinoma and benign prostatic hyperplasia.

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Pretlow, T G; Pretlow, T P; Yang, B; Kaetzel, C S; Delmoro, C M; Kamis, S M; Bodner, D R; Kursh, E; Resnick, M I; Bradley, E L

1991-11-11

Prostate-specific antigen (PSA), as measured in peripheral blood, is currently the most widely used marker for the assessment of tumor burden in the longitudinal study of patients with carcinoma of the prostate (PCA). Studies from other laboratories have led to the conclusion that a given volume of PCA causes a much higher level of PSA in the peripheral circulation of patients than a similar volume of prostate without carcinoma. We have evaluated PSA in the resected tissues immunohistochemically and in extracts of PCA and of prostates resected because of benign prostatic hyperplasia (BPH) with an enzyme-linked immunosorbent assay. Immunohistochemical results were less quantitative than but consistent with the results of the ELISA of tissue extracts. Immunohistochemically, there was considerable heterogeneity in the expression of PSA by both PCA and BPH both within and among prostatic tissues from different patients. While the levels of expression of PSA in these tissues overlap broadly, PSA is expressed at a lower level in PCA than in BPH when PSA is expressed as a function of wet weight of tissue (p = 0.0095), wet weight of tissue/% epithelium (p less than 0.0001), protein extracted from the tissue (p = 0.0039), or protein extracted/% epithelium (p less than 0.0001).

Precision cancer immunotherapy: optimizing dendritic cell-based strategies to induce tumor antigen-specific T-cell responses against individual patient tumors.

Science.gov (United States)

Osada, Takuya; Nagaoka, Koji; Takahara, Masashi; Yang, Xiao Yi; Liu, Cong-Xiao; Guo, Hongtao; Roy Choudhury, Kingshuk; Hobeika, Amy; Hartman, Zachary; Morse, Michael A; Lyerly, H Kim

2015-05-01

Most dendritic cell (DC)-based vaccines have loaded the DC with defined antigens, but loading with autologos tumor-derived antigens would generate DCs that activate personalized tumor-specific T-cell responses. We hypothesized that DC matured with an optimized combination of reagents and loaded with tumor-derived antigens using a clinically feasible electroporation strategy would induce potent antitumor immunity. We first studied the effects on DC maturation and antigen presentation of the addition of picibanil (OK432) to a combination of zoledronic acid, tumor necrosis factor-α, and prostaglandin E2. Using DC matured with the optimized combination, we tested 2 clinically feasible sources of autologous antigen for electroloading, total tumor mRNA or total tumor lysate, to determine which stimulated more potent antigen-specific T cells in vitro and activated more potent antitumor immunity in vivo. The combination of tumor necrosis factor-α/prostaglandin E2/zoledronic acid/OK432 generated DC with high expression of maturation markers and antigen-specific T-cell stimulatory function in vitro. Mature DC electroloaded with tumor-derived mRNA [mRNA electroporated dendritic cell (EPDC)] induced greater expansion of antigen-specific T cells in vitro than DC electroloaded with tumor lysate (lysate EPDC). In a therapeutic model of MC38-carcinoembryonic antigen colon cancer-bearing mice, vaccination with mRNA EPDC induced the most efficient anti-carcinoembryonic antigen cellular immune response, which significantly suppressed tumor growth. In conclusion, mature DC electroloaded with tumor-derived mRNA are a potent cancer vaccine, especially useful when specific tumor antigens for vaccination have not been identified, allowing autologous tumor, and if unavailable, allogeneic cell lines to be used as an unbiased source of antigen. Our data support clinical testing of this strategy.

Sharing specific "We" autobiographical memories in close relationships: the role of contact frequency.

Science.gov (United States)

Beike, Denise R; Cole, Holly E; Merrick, Carmen R

2017-11-01

Sharing memories in conversations with close others is posited to be part of the social function of autobiographical memory. The present research focused on the sharing of a particular type of memory: Specific memories about one-time co-experienced events, which we termed Specific We memories. Two studies with 595 total participants examined the factors that lead to and/or are influenced by the sharing of Specific We memories. In Study 1, participants reported on their most recent conversation. Specific We memories were reportedly discussed most often in conversations with others who were close and with whom the participant had frequent communication. In Study 2, participants were randomly assigned either to increase or to simply record the frequency of communication with a close other (parent). Increases in the frequency of reported sharing of Specific We memories as well as closeness to the parent resulted. Mediation analyses of both studies revealed causal relationships among reported sharing of Specific We memories and closeness. We discuss the relevance of these results for understanding the social function of autobiographical memory.

Microfluidic-integrated patterned ITO immunosensor for rapid detection of prostate-specific membrane antigen biomarker in prostate cancer.

Science.gov (United States)

Seenivasan, Rajesh; Singh, Chandra K; Warrick, Jay W; Ahmad, Nihal; Gunasekaran, Sundaram

2017-09-15

An optically transparent patterned indium tin oxide (ITO) three-electrode sensor integrated with a microfluidic channel was designed for label-free immunosensing of prostate-specific membrane antigen (PSMA), a prostate cancer (PCa) biomarker, expressed on prostate tissue and circulating tumor cells but also found in serum. The sensor relies on cysteamine capped gold nanoparticles (N-AuNPs) covalently linked with anti-PSMA antibody (Ab) for target specificity. A polydimethylsiloxane (PDMS) microfluidic channel is used to efficiently and reproducibly introduce sample containing soluble proteins/cells to the sensor. The PSMA is detected and quantified by measuring the change in differential pulse voltammetry signal of a redox probe ([Fe(CN) 6 ] 3- /[Fe(CN) 6 ] 4- ) that is altered upon binding of PSMA with PSMA-Ab immobilized on N-AuNPs/ITO. Detection of PSMA expressing cells and soluble PSMA was tested. The limit of detection (LOD) of the sensor for PSMA-based PCa cells is 6/40µL (i.e., 150 cells/mL) (n=3) with a linear range of 15-400 cells/40µL (i.e., 375-10,000 cells/mL), and for the soluble PSMA is 0.499ng/40µL (i.e., 12.5ng/mL) (n=3) with the linear range of 0.75-250ng/40µL (i.e., 19-6250ng/mL), both with an incubation time of 10min. The results indicate that the sensor has a suitable sensitivity and dynamic range for routine detection of PCa circulating tumor cells and can be adapted to detect other biomarkers/cancer cells. Copyright © 2017 Elsevier B.V. All rights reserved.

Development and evaluation of tailored specific real-time RT-PCR assays for detection of foot-and-mouth disease virus serotypes circulating in East Africa.

Science.gov (United States)

Bachanek-Bankowska, Katarzyna; Mero, Herieth R; Wadsworth, Jemma; Mioulet, Valerie; Sallu, Raphael; Belsham, Graham J; Kasanga, Christopher J; Knowles, Nick J; King, Donald P

2016-11-01

Rapid, reliable and accurate diagnostic methods provide essential support to programmes that monitor and control foot-and-mouth disease (FMD). While pan-specific molecular tests for FMD virus (FMDV) detection are well established and widely used in endemic and FMD-free countries, current serotyping methods mainly rely either on antigen detection ELISAs or nucleotide sequencing approaches. This report describes the development of a panel of serotype-specific real-time RT-PCR assays (rRT-PCR) tailored to detect FMDV lineages currently circulating in East Africa. These assays target sequences within the VP1-coding region that share high intra-lineage identity, but do not cross-react with FMD viruses from other serotypes that circulate in the region. These serotype-specific assays operate with the same thermal profile as the pan-diagnostic tests making it possible to run them in parallel to produce C T values comparable to the pan-diagnostic test detecting the 3D-coding region. These assays were evaluated alongside the established pan-specific molecular test using field samples and virus isolates collected from Tanzania, Kenya and Ethiopia that had been previously characterised by nucleotide sequencing. Samples (n=71) representing serotype A (topotype AFRICA, lineage G-I), serotype O (topotypes EA-2 and EA-4), serotype SAT 1 (topotype I (NWZ)) and serotype SAT2 (topotype IV) were correctly identified with these rRT-PCR assays. Furthermore, FMDV RNA from samples that did not contain infectious virus could still be serotyped using these assays. These serotype-specific real-time RT-PCR assays can detect and characterise FMDVs currently circulating in East Africa and hence improve disease control in this region. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Unraveling the linguistic nature of specific autobiographical memories using a computerized classification algorithm.

Science.gov (United States)

Takano, Keisuke; Ueno, Mayumi; Moriya, Jun; Mori, Masaki; Nishiguchi, Yuki; Raes, Filip

2017-06-01

In the present study, we explored the linguistic nature of specific memories generated with the Autobiographical Memory Test (AMT) by developing a computerized classifier that distinguishes between specific and nonspecific memories. The AMT is regarded as one of the most important assessment tools to study memory dysfunctions (e.g., difficulty recalling the specific details of memories) in psychopathology. In Study 1, we utilized the Japanese corpus data of 12,400 cue-recalled memories tagged with observer-rated specificity. We extracted linguistic features of particular relevance to memory specificity, such as past tense, negation, and adverbial words and phrases pertaining to time and location. On the basis of these features, a support vector machine (SVM) was trained to classify the memories into specific and nonspecific categories, which achieved an area under the curve (AUC) of .92 in a performance test. In Study 2, the trained SVM was tested in terms of its robustness in classifying novel memories (n = 8,478) that were retrieved in response to cue words that were different from those used in Study 1. The SVM showed an AUC of .89 in classifying the new memories. In Study 3, we extended the binary SVM to a five-class classification of the AMT, which achieved 64%-65% classification accuracy, against the chance level (20%) in the performance tests. Our data suggest that memory specificity can be identified with a relatively small number of words, capturing the universal linguistic features of memory specificity across memories in diverse contents.

Skin-resident memory CD4+ T cells enhance protection against Leishmania major infection.

Science.gov (United States)

Glennie, Nelson D; Yeramilli, Venkata A; Beiting, Daniel P; Volk, Susan W; Weaver, Casey T; Scott, Phillip

2015-08-24

Leishmaniasis causes a significant disease burden worldwide. Although Leishmania-infected patients become refractory to reinfection after disease resolution, effective immune protection has not yet been achieved by human vaccines. Although circulating Leishmania-specific T cells are known to play a critical role in immunity, the role of memory T cells present in peripheral tissues has not been explored. Here, we identify a population of skin-resident Leishmania-specific memory CD4+ T cells. These cells produce IFN-γ and remain resident in the skin when transplanted by skin graft onto naive mice. They function to recruit circulating T cells to the skin in a CXCR3-dependent manner, resulting in better control of the parasites. Our findings are the first to demonstrate that CD4+ TRM cells form in response to a parasitic infection, and indicate that optimal protective immunity to Leishmania, and thus the success of a vaccine, may depend on generating both circulating and skin-resident memory T cells. © 2015 Glennie et al.

Frequency-specific insight into short-term memory capacity.

Science.gov (United States)

Feurra, Matteo; Galli, Giulia; Pavone, Enea Francesco; Rossi, Alessandro; Rossi, Simone

2016-07-01

The digit span is one of the most widely used memory tests in clinical and experimental neuropsychology for reliably measuring short-term memory capacity. In the forward version, sequences of digits of increasing length have to be reproduced in the order in which they are presented, whereas in the backward version items must be reproduced in the reversed order. Here, we assessed whether transcranial alternating current stimulation (tACS) increases the memory span for digits of young and midlife adults. Imperceptibly weak electrical currents in the alpha (10 Hz), beta (20 Hz), theta (5 Hz), and gamma (40 Hz) range, as well as a sham stimulation, were delivered over the left posterior parietal cortex, a cortical region thought to sustain maintenance processes in short-term memory through oscillatory brain activity in the beta range. We showed a frequency-specific effect of beta-tACS that robustly increased the forward memory span of young, but not middle-aged, healthy individuals. The effect correlated with age: the younger the subjects, the greater the benefit arising from parietal beta stimulation. Our results provide evidence of a short-term memory capacity improvement in young adults by online frequency-specific tACS application. Copyright © 2016 the American Physiological Society.

Development of an epitope panel for consistent identification of antigen-specific T-cells in humans

DEFF Research Database (Denmark)

Fløe, Andreas; Løppke, Caroline; Hilberg, Ole

2017-01-01

Objective We aimed to establish a panel of MHC-peptide multimers suitable as a positive control in detection of HLA A*0201 restricted antigen specific T-cells (ASTC) by flow cytometry. Materials and methods MHC Dextramers were loaded with HLA A*0201 binding peptides from viral antigens and melano...

Activation of nickel-specific CD4+ T lymphocytes in the absence of professional antigen-presenting cells.

Science.gov (United States)

Nasorri, Francesca; Sebastiani, Silvia; Mariani, Valentina; De Pità, Ornella; Puddu, Pietro; Girolomoni, Giampiero; Cavani, Andrea

2002-01-01

Allergic contact dermatitis ensues from exaggerated T cell responses to haptens. Dendritic cells are required for the initiation of hapten sensitization, but they may not be necessary for disease expression. Here we investigated the antigen-presenting cell requirement of nickel-specific CD4+ lymphocytes isolated from the blood of six allergic individuals. A significant proportion (42 out of 121; 35%) of the T cell clones proliferated in vitro to nickel also in the absence of professional antigen-presenting cells, suggesting a direct T-T hapten presentation. Antigen-presenting-cell-independent T cells showed a predominant T helper 1 phenotype. Nickel recognition by these T cells was major histocompatibility complex class II restricted, not influenced by CD28 triggering, independent from their state of activation, and did not require processing. The capacity of this T cell subset to be directly stimulated by nickel was not due to unique antigen-presenting properties, as both antigen-presenting-cell-dependent and antigen-presenting-cell-independent clones displayed comparable levels of HLA-DR, CD80, and CD86, and were equally capable of presenting nickel to antigen-presenting-cell-independent clones. In contrast, neither T cell types activated antigen-presenting-cell-dependent T lymphocytes. T-T presentation induced T cell receptor downregulation, CD25, CD80, CD86, and HLA-DR upregulation, and interferon-gamma release, although to a lesser extent compared to those induced by dendritic cell-T presentation. Following T-T presentation, the clones did not undergo unresponsiveness and maintained the capacity to respond to dendritic cells pulsed with antigen. In aggregate, our data suggest that antigen-presenting-cell-independent T cell activation can effectively amplify hapten- specific immune responses.

Sensitive and Specific Biomimetic Lipid Coated Microfluidics to Isolate Viable Circulating Tumor Cells and Microemboli for Cancer Detection.

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Jia-Yang Chen

Full Text Available Here we presented a simple and effective membrane mimetic microfluidic device with antibody conjugated supported lipid bilayer (SLB "smart coating" to capture viable circulating tumor cells (CTCs and circulating tumor microemboli (CTM directly from whole blood of all stage clinical cancer patients. The non-covalently bound SLB was able to promote dynamic clustering of lipid-tethered antibodies to CTC antigens and minimized non-specific blood cells retention through its non-fouling nature. A gentle flow further flushed away loosely-bound blood cells to achieve high purity of CTCs, and a stream of air foam injected disintegrate the SLB assemblies to release intact and viable CTCs from the chip. Human blood spiked cancer cell line test showed the ~95% overall efficiency to recover both CTCs and CTMs. Live/dead assay showed that at least 86% of recovered cells maintain viability. By using 2 mL of peripheral blood, the CTCs and CTMs counts of 63 healthy and colorectal cancer donors were positively correlated with the cancer progression. In summary, a simple and effective strategy utilizing biomimetic principle was developed to retrieve viable CTCs for enumeration, molecular analysis, as well as ex vivo culture over weeks. Due to the high sensitivity and specificity, it is the first time to show the high detection rates and quantity of CTCs in non-metastatic cancer patients. This work offers the values in both early cancer detection and prognosis of CTC and provides an accurate non-invasive strategy for routine clinical investigation on CTCs.

Sensory memory consolidation observed: Increased specificity of detail over days

Science.gov (United States)

Weinberger, Norman M.; Miasnikov, Alexandre A.; Chen, Jemmy C.

2010-01-01

Memories are usually multidimensional, including contents such as sensory details, motivational state and emotional overtones. Memory contents generally change over time, most often reported as a loss in the specificity of detail. To study the temporal changes in the sensory contents of associative memory without motivational and emotional contents, we induced memory for acoustic frequency by pairing a tone with stimulation of the cholinergic nucleus basalis. Adult male rats were first tested for behavioral responses (disruption of ongoing respiration) to tones (1–15 kHz), yielding pre-training behavioral frequency generalization gradients (BFGG). They next received three days of training consisting of a conditioned stimulus (CS) tone (8.00 kHz, 70 dB, 2 s) either Paired (n = 5) or Unpaired (n = 5) with weak electrical stimulation (~48 μA) of the nucleus basalis (100 Hz, 0.2 s, co-terminating with CS offset). Testing for behavioral memory was performed by obtaining post-training BFGGs at two intervals, 24 and 96 h after training. At 24 h post-training, the Paired group exhibited associative behavioral memory manifested by significantly larger responses to tone than the Unpaired group. However, they exhibited no specificity in memory for the frequency of the tonal CS, as indexed by a flat BFGG. In contrast, after 96 h post-training the Paired group did exhibit specificity of memory as revealed by tuned BFGGs with a peak at the CS-band of frequencies. This increased detail of memory developed due to a loss of response to lower and higher frequency side-bands, without any change in the absolute magnitude of response to CS-band frequencies. These findings indicate that the sensory contents of associative memory can be revealed to become more specific, through temporal consolidation in the absence of non-sensory factors such as motivation and emotion. PMID:19038352

Sensory memory consolidation observed: increased specificity of detail over days.

Science.gov (United States)

Weinberger, Norman M; Miasnikov, Alexandre A; Chen, Jemmy C

2009-03-01

Memories are usually multidimensional, including contents such as sensory details, motivational state and emotional overtones. Memory contents generally change over time, most often reported as a loss in the specificity of detail. To study the temporal changes in the sensory contents of associative memory without motivational and emotional contents, we induced memory for acoustic frequency by pairing a tone with stimulation of the cholinergic nucleus basalis. Adult male rats were first tested for behavioral responses (disruption of ongoing respiration) to tones (1-15 kHz), yielding pre-training behavioral frequency generalization gradients (BFGG). They next received three days of training consisting of a conditioned stimulus (CS) tone (8.00 kHz, 70 dB, 2 s) either Paired (n=5) or Unpaired (n=5) with weak electrical stimulation (approximately 48 microA) of the nucleus basalis (100 Hz, 0.2 s, co-terminating with CS offset). Testing for behavioral memory was performed by obtaining post-training BFGGs at two intervals, 24 and 96 h after training. At 24 h post-training, the Paired group exhibited associative behavioral memory manifested by significantly larger responses to tone than the Unpaired group. However, they exhibited no specificity in memory for the frequency of the tonal CS, as indexed by a flat BFGG. In contrast, after 96 h post-training the Paired group did exhibit specificity of memory as revealed by tuned BFGGs with a peak at the CS-band of frequencies. This increased detail of memory developed due to a loss of response to lower and higher frequency side-bands, without any change in the absolute magnitude of response to CS-band frequencies. These findings indicate that the sensory contents of associative memory can be revealed to become more specific, through temporal consolidation in the absence of non-sensory factors such as motivation and emotion.

Changes in B Cell Populations and Merozoite Surface Protein-1-Specific Memory B Cell Responses after Prolonged Absence of Detectable P. falciparum Infection.

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Cyrus Ayieko

Full Text Available Clinical immunity to malaria declines in the absence of repeated parasite exposure. However, little is known about how B cell populations and antigen-specific memory B cells change in the absence of P. falciparum infection. A successful indoor residual insecticide spraying campaign in a highland area of western Kenya, led to an absence of blood-stage P. falciparum infection between March 2007 and April 2008. We assessed memory B cell responses in 45 adults at the beginning (April 2008 and end (April 2009 of a subsequent 12-month period during which none of the adults had evidence of asymptomatic parasitemia or clinical disease. Antibodies and memory B cells to the 42-kDa portion of the merozoite surface protein-1 (MSP-142 were measured using ELISA and ELISPOT assays, respectively. B cell populations were characterized by flow cytometry. From 2008 to 2009, the prevalence of MSP-142-specific memory B cells (45% vs. 55%, respectively, P = 0.32 or antibodies (91% vs. 82%, respectively, P = 0.32 did not differ significantly, although specific individuals did change from positive to negative and vice versa, particularly for memory B cells, suggesting possible low-level undetected parasitemia may have occurred in some individuals. The magnitude of MSP-142-specific memory B cells and levels of antibodies to MSP-142 also did not differ from 2008 to 2009 (P>0.10 for both. However, from 2008 to 2009 the proportions of both class-switched atypical (CD19+IgD-CD27-CD21-IgM- and class-switched activated (CD19+IgD-CD27+CD21-IgM- memory B cells decreased (both P<0.001. In contrast, class-switched resting classical memory B cells (CD19+IgD-CD27+CD21+IgM- increased (P<0.001. In this area of seasonal malaria transmission, a one- year absence of detectable P. falciparum infection was not associated with changes in the prevalence or level of MSP-142 specific memory B cells, but was associated with major changes in overall memory B cell subsets.

Autoreactive T effector memory differentiation mirrors β-cell function in type 1 diabetes.

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Yeo, Lorraine; Woodwyk, Alyssa; Sood, Sanjana; Lorenc, Anna; Eichmann, Martin; Pujol-Autonell, Irma; Melchiotti, Rossella; Skowera, Ania; Fidanis, Efthymios; Dolton, Garry M; Tungatt, Katie; Sewell, Andrew K; Heck, Susanne; Saxena, Alka; Beam, Craig A; Peakman, Mark

2018-05-31

In type 1 diabetes, cytotoxic CD8 T cells with specificity for β-cell autoantigens are found in the pancreatic islets where they are implicated in the destruction of insulin-secreting β cells. In contrast, the disease relevance of β-cell-reactive CD8 T cells that are detectable in the circulation, and their relationship to β-cell function, are not known. Here, we tracked multiple, circulating β-cell-reactive CD8 T cell subsets and measured β-cell function longitudinally for two years, starting immediately after diagnosis of type 1 diabetes. We found that change in β-cell-specific effector memory CD8 T cells expressing CD57 was positively correlated with C-peptide change in subjects below 12 years of age. Autoreactive CD57+ effector memory CD8 T cells bore the signature of enhanced effector function (higher expression of granzyme B, killer specific protein 37 and CD16, and reduced expression of CD28) compared with their CD57-negative counterparts, and network association modelling indicated that the dynamics of β-cell-reactive CD57+ effector memory CD8 T cell subsets were strongly linked. Thus, coordinated changes in circulating β-cell-specific CD8 T cells within the CD57+ effector memory subset calibrate to functional insulin reserve in type 1 diabetes, providing a tool for immune monitoring and a mechanism-based target for immunotherapy.

Follow-up of neurocysticercosis patients after treatment using an antigen detection ELISA

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Nguekam

2003-03-01

Full Text Available Seven patients with active neurocysticercosis (NCC received an eight days treatment with albendazole and were followed up using computed tomography (CT-scan and a monoclonal antibody based ELISA for the detection of circulating antigen (Ag-ELISA. Only three patients were cured as was shown by CT-scan and by the disappearance of circulating antigens one month after treatment. After a second course of albendazole therapy, two other patients became seronegative. CT-scan showed the disappearance of viable cysts in all persons who became seronegative whereas patients who were not cured remained seropositive. These preliminary results show that this Ag-ELISA is a promising technique for monitoring the success of treatment of NCC patients because of the excellent correlation between the presence of circulating antigens and of viable brain cysts.

Original antigenic sin: A comprehensive review.

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

2017-09-01

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

Mother-child reminiscing and autobiographical memory specificity among preschool-age children.

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Valentino, Kristin; Nuttall, Amy K; Comas, Michelle; McDonnell, Christina G; Piper, Brianna; Thomas, Taylor E; Fanuele, Suzanne

2014-04-01

Overgeneral memory (OGM) refers to difficulty in retrieving specific autobiographical memories. The tendency to be overgeneral in autobiographical memory recall is more commonly observed among individuals with emotional disorders compared with those without. Despite significant advances in theory and identification of mechanisms that underlie the etiology of OGM, there has been little integration between normative research on the development of autobiographical memory and research on OGM. Informed by a developmental psychopathology perspective and drawing on normative developmental research on the social construction of autobiographical memory, the current investigation examined whether the elaborative quantity and elaborative quality of maternal reminiscing are predictive of preschool-age children's autobiographical memory specificity. Additionally, this investigation tested whether children's positive self-representations may explain these hypothesized associations. Participants consisted of 95 mother-child dyads. Children's ages ranged between 3.5 and 6 years, and the sample was predominantly low income and of minority race/ethnicity. Dyads participated in a joint reminiscing task about 4 past events, and children participated in assessments of autobiographical memory specificity and self-representations. Results indicated that the elaborative quality, defined by maternal-sensitive guidance and emotional narrative coherence, but not the elaborative quantity, of maternal reminiscing style was significantly associated with children's autobiographical memory specificity. Additionally, there was support for an indirect pathway between maternal reminiscing quality and child memory specificity through children's positive self-representations. Directions for future research are discussed, and potential clinical implications are addressed. PsycINFO Database Record (c) 2014 APA, all rights reserved.

High affinity antigen recognition of the dual specific variants of herceptin is entropy-driven in spite of structural plasticity.

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Jenny Bostrom

Full Text Available The antigen-binding site of Herceptin, an anti-human Epidermal Growth Factor Receptor 2 (HER2 antibody, was engineered to add a second specificity toward Vascular Endothelial Growth Factor (VEGF to create a high affinity two-in-one antibody bH1. Crystal structures of bH1 in complex with either antigen showed that, in comparison to Herceptin, this antibody exhibited greater conformational variability, also called "structural plasticity". Here, we analyzed the biophysical and thermodynamic properties of the dual specific variants of Herceptin to understand how a single antibody binds two unrelated protein antigens. We showed that while bH1 and the affinity-improved bH1-44, in particular, maintained many properties of Herceptin including binding affinity, kinetics and the use of residues for antigen recognition, they differed in the binding thermodynamics. The interactions of bH1 and its variants with both antigens were characterized by large favorable entropy changes whereas the Herceptin/HER2 interaction involved a large favorable enthalpy change. By dissecting the total entropy change and the energy barrier for dual interaction, we determined that the significant structural plasticity of the bH1 antibodies demanded by the dual specificity did not translate into the expected increase of entropic penalty relative to Herceptin. Clearly, dual antigen recognition of the Herceptin variants involves divergent antibody conformations of nearly equivalent energetic states. Hence, increasing the structural plasticity of an antigen-binding site without increasing the entropic cost may play a role for antibodies to evolve multi-specificity. Our report represents the first comprehensive biophysical analysis of a high affinity dual specific antibody binding two unrelated protein antigens, furthering our understanding of the thermodynamics that drive the vast antigen recognition capacity of the antibody repertoire.

Working, declarative and procedural memory in specific language impairment

DEFF Research Database (Denmark)

Lum, J. A. G.; Conti-Ramsden, G.; Page, D.

2012-01-01

at declarative memory for visual information, and at declarative memory in the verbal domain after controlling for working memory and language. Visuo-spatial short-term memory was intact, whereas verbal working memory was impaired, even when language deficits were held constant. Correlation analyses showed......According to the Procedural Deficit Hypothesis (PDH), abnormalities of brain structures underlying procedural memory largely explain the language deficits in children with specific language impairment (SLI). These abnormalities are posited to result in core deficits of procedural memory, which...... in turn explain the grammar problems in the disorder. The abnormalities are also likely to lead to problems with other, non-procedural functions, such as working memory, that rely at least partly on the affected brain structures. In contrast, declarative memory is expected to remain largely intact...

Co-delivery of antigen and IL-12 by Venezuelan equine encephalitis virus replicon particles enhances antigen-specific immune responses and anti-tumor effects

Science.gov (United States)

Osada, Takuya; Berglund, Peter; Morse, Michael A.; Hubby, Bolyn; Lewis, Whitney; Niedzwiecki, Donna; Hobeika, Amy; Burnett, Bruce; Devi, Gayathri R.; Clay, Timothy M.; Smith, Jonathan; Lyerly, H. Kim

2013-01-01

We recently demonstrated that Venezuelan equine encephalitis (VEE) virus-based replicon particles (VRP) encoding tumor antigens could break tolerance in the immunomodulatory environment of advanced cancer. We hypothesized that local injection of VRP expressing Interleukin-12 (IL-12) at the site of injections of VRP-based cancer vaccines would enhance the tumor-antigen-specific T cell and antibody responses and anti-tumor efficacy. Mice were immunized with VRP encoding the human tumor-associated antigen, carcinoembryonic antigen (CEA) (VRP-CEA(6D)) and VRP-IL-12 was also administered at the same site or at a distant location. CEA-specific T cell and antibody responses were measured. To determine antitumor activity, mice were implanted with MC38-CEA-2 cells and immunized with VRP-CEA with and without VRP-IL-12 and tumor growth and mouse survival were measured. VRP-IL-12 greatly enhanced CEA-specific T cell and antibody responses when combined with VRP-CEA(6D) vaccination. VRP IL-12 was superior to IL-12 protein at enhancing immune responses. Vaccination with VRP-CEA(6D) plus VRP-IL-12 was superior to VRP-CEA(6D) or VRP-IL-12 alone in inducing anti-tumor activity and prolonging survival in tumor-bearing mice. Importantly, local injection of VRP-IL-12 at the VRP-CEA(6D) injection site provided more potent activation of CEA-specific immune responses than VRP-IL-12 injected at a distant site from the VRP-CEA injections. Together, this study shows that VRP-IL-12 enhances vaccination with VRP-CEA(6D) and was more effective at activating CEA-specific T cell responses when locally expressed at the vaccine site. Clinical trials evaluating the adjuvant effect of VRP-IL-12 at enhancing the immunogenicity of cancer vaccines are warranted. PMID:22488274

The end of the road for prostate specific antigen testing? | Nna ...

African Journals Online (AJOL)

Many candidate biomarkers for diagnosis of prostate cancer have been investigated, but prostate‑specific antigen (PSA) testing remains the frontline test for both mass screening and individual clinical testing. Although the PSA test is cost‑effective, analytically reliable, and flexibly high throughput, it has a very weak ...

Clinical implications of free-to-total immunoreactive prostate-specific antigen ratios

NARCIS (Netherlands)

Wymenga, LFA; Duisterwinkel, FJ; Groenier, K; Visser-van Brummen, P; Marrink, J; Mensink, HJA

Objective: A study was performed to evaluate the free-to-total prostate-specific antigen (PSA) ratio for discriminating benign prostatic hyperplasia (BPH) or prostate cancer in the intermediate PSA range (2.0-10.0 mu g/l) in patients referred for prostate evaluation. In addition, the relationship of

PROSTATE-SPECIFIC ANTIGEN A Clue for the Prostatic Origin of Metastasis

OpenAIRE

MANABE, Toshiaki; TSUKAYAMA, Chotatsu; YAMAGUCHI, Masae; YAMASHITA, Koshi

1983-01-01

The prostate-specific antigen is a recently purified glycoprotein which is present only in the prostatic gland. In order to confirm the usefulness of this protein in isolating prostatic carcinomas from socalled metastatic carcinomas of unknown primary site, we immunohistochemically studied 19 non-neoplastic prostatic tissue, 18 primary carcinomas of the prostate, and 32 non-prostatic adenocarcinomas. From our study, we concluded that PSA is highly specific for the prostatic carcinomas. The ab...

Urinary prostate-specific antigen: predictor of benign prostatic hyperplasia progression?

Science.gov (United States)

Pejcic, Tomislav P; Tulic, Cane Dz; Lalic, Natasa V; Glisic, Biljana D; Ignjatovic, Svetlana D; Markovic, Biljana B; Hadzi-Djokic, Jovan B

2013-04-01

Urinary prostate-specific antigen (uPSA) can be used as additional parameter of benign prostatic hyperplasia (BPH) progression. From January 2001 to December 2011, uPSA was determined in 265 patients with benign prostate. Based on total prostate volume (TPV), the patients with benign prostate were divided in two groups: TPV specificity of 0.83 and sensitivity of 0.67. The level of uPSA reflects prostatic hormonal activity and correlates with TPV, PSA and age. UPSA level ≥ 150 ng/mL can be used as additional predictive parameter of BPH progression.

The role of cytokines in T-cell memory in health and disease.

Science.gov (United States)

Raeber, Miro E; Zurbuchen, Yves; Impellizzieri, Daniela; Boyman, Onur

2018-05-01

Upon stimulation with their cognate antigen, naive T cells undergo proliferation and differentiation into effector cells, followed by apoptosis or survival as precursors of long-lived memory cells. These phases of a T-cell response and the ensuing maintenance of memory T cells are shaped by cytokines, most notably interleukin-2 (IL-2), IL-7, and IL-15 that share the common γ chain (γ c ) cytokine receptor. Steady-state production of IL-7 and IL-15 is necessary for background proliferation and homeostatic survival of CD4 + and CD8 + memory T cells. During immune responses, augmented levels of IL-2, IL-15, IL-21, IL-12, IL-18, and type-I interferons determine the memory potential of antigen-specific effector CD8 + cells, while increased IL-2 and IL-15 cause bystander proliferation of heterologous CD4 + and CD8 + memory T cells. Limiting availability of γ c cytokines, reduction in regulatory T cells or IL-10, and persistence of inflammation or cognate antigen can result in memory T cells, which fail to become cytokine-dependent long-lived cells. Conversely, increased IL-7 and IL-15 can expand memory T cells, including pathogenic tissue-resident memory T cells, as seen in lymphopenia and certain chronic-inflammatory disorders and malignancies. These abovementioned factors impact immunotherapy and vaccines directed at memory T cells in cancer and chronic infection. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Medial prefrontal-hippocampal connectivity during emotional memory encoding predicts individual differences in the loss of associative memory specificity

NARCIS (Netherlands)

Berkers, R.M.W.J.; Klumpers, F.; Fernandez, G.S.E.

2016-01-01

Emotionally charged items are often remembered better, whereas a paradoxical loss of specificity is found for associative emotional information (specific memory). The balance between specific and generalized emotional memories appears to show large individual differences, potentially related to

Medial prefrontal–hippocampal connectivity during emotional memory encoding predicts individual differences in the loss of associative memory specificity

NARCIS (Netherlands)

Berkers, R.M.W.J.; Klumpers, F.; Fernandez, G.S.E.

2016-01-01

Emotionally charged items are often remembered better, whereas a paradoxical loss of specificity is found for associative emotional information (specific memory). The balance between specific and generalized emotional memories appears to show large individual differences, potentially related to

Mycobacterium tuberculosis-specific memory NKT cells in patients with tuberculous pleurisy.

Science.gov (United States)

Li, Zitao; Yang, Binyan; Zhang, Yannan; Ma, Jiangjun; Chen, Xinchun; Lao, Suihua; Li, Baiqing; Wu, Changyou

2014-11-01

Natural killer T (NKT) cells from mouse and human play a protective role in the immune responses against the infection of Mycobacterium tuberculosis. However, the characteristic of CD3(+)TCRvβ11(+) NKT cells at the local site of M. tuberculosis infection remains poorly defined. In the present study, we found that the numbers of CD3(+)TCRvβ11(+) NKT cells in pleural fluid mononuclear cells (PFMCs) were significantly lower than those in peripheral blood mononuclear cells (PBMCs). However, CD3(+)TCRvβ11(+) NKT cells from PFMCs spontaneously expressed high levels of CD69 and CD25 and effector memory phenotypes of CD45RO(high)CD62L(low)CCR7(low). After stimulation with the antigens of M. tuberculosis, CD3(+)TCRvβ11(+) NKT cells from PFMCs produced high levels of IFN-γ. Sorted CD3(+)TCRvβ11(+) NKT cells from PFMCs cultured with antigen presenting cells (APCs) produced IFN-γ protein and mRNA. The production of IFN-γ could be completely inhibited by AG490 and Wortmannin. In addition, CD3(+)TCRvβ11(+) NKT cells from PFMCs expressed higher levels of Fas (CD95), FasL (CD178) and perforin but lower levels of granzyme B compared with those from PBMCs. Taken together, our data demonstrated for the first time that M. tuberculosis-specific CD3(+)TCRvβ11(+) NKT cells participated in the local immune responses against M. tuberculosis through the production of IFN-γ and the secretion of cytolytic molecules.

Serum androgens and prostate-specific antigen levels in androgenetic alopecia: is there a difference between frontal and vertex baldness?

Science.gov (United States)

Lis-Święty, A; Arasiewicz, H; Ranosz-Janicka, I; Brzezińska-Wcisło, L

2017-12-13

Androgenetic alopecia (AGA) seems to be a marker of increased risk of prostate cancer (PCa). We sought to investigate potential pathophysiological differences between frontal and vertex balding that might have the impact on the incidence of PCa. Serum concentrations of testosterone (T), dihydrotestosterone (DHT) and prostate-specific antigen (PSA) were measured in 88 subjects with AGA. We have examined sixty patients with frontal baldness and 28 patients with vertex baldness. The subgroups did not differ significantly in age, BMI and as regards age of AGA onset, duration of AGA and comorbidities. The mean value of DHT in serum of the men with vertex baldness was higher than those in the men with frontal baldness with statistical significance (P baldness may signal higher exposures to circulating DHT. Serum PSA level cannot serve as surrogate diagnostic marker of increased androgenic activity in men with AGA. © 2017 European Academy of Dermatology and Venereology.

Anti-IL-5 attenuates activation and surface density of β2-integrins on circulating eosinophils after segmental antigen challenge

Science.gov (United States)

Johansson, Mats W.; Gunderson, Kristin A.; Kelly, Elizabeth A. B.; Denlinger, Loren C.; Jarjour, Nizar N.; Mosher, Deane F.

2013-01-01

Background IL-5 activates αMβ2 integrin on blood eosinophils in vitro. Eosinophils in bronchoalveolar lavage (BAL) following segmental antigen challenge have activated β2-integrins. Objective To identify roles for IL-5 in regulating human eosinophil integrins in vivo. Methods Blood and BAL eosinophils were analyzed by flow cytometry in ten subjects with allergic asthma who underwent a segmental antigen challenge protocol before and after anti-IL-5 administration. Results Blood eosinophil reactivity with monoclonal antibody (mAb) KIM-127, which recognizes partially activated β2-integrins, was decreased after anti-IL-5. Before anti-IL-5, surface densities of blood eosinophil β2, αM, and αL integrin subunits increased modestly post-challenge. After anti-IL-5, such increases did not occur. Before or after anti-IL-5, surface densities of β2,αM, αL, and αD and reactivity with KIM-127 and mAb CBRM1/5, which recognizes high-activity αMβ2, were similarly high on BAL eosinophils 48 h post-challenge. Density and activation state of β1-integrins on blood and BAL eosinophils were not impacted by anti-IL-5, even though anti-IL-5 ablated a modest post-challenge increase on blood or BAL eosinophils of P-selectin glycoprotein ligand-1 (PSGL-1), a receptor for P-selectin that causes activation of β1-integrins. Forward scatter of blood eosinophils post-challenge was less heterogeneous and on the average decreased after anti-IL-5; however, anti-IL-5 had no effect on the decreased forward scatter of eosinophils in post-challenge BAL compared to eosinophils in blood. Blood eosinophil KIM-127 reactivity at the time of challenge correlated with the percentage of eosinophils in BAL post-challenge. Conclusion and Clinical Relevance IL-5 supports a heterogeneous population of circulating eosinophils with partially activated β2-integrins and is responsible for upregulation of β2-integrins and PSGL-1 on circulating eosinophils following segmental antigen challenge but has

Visualization of antigen-specific human cytotoxic T lymphocytes labeled with superparamagnetic iron-oxide particles

Energy Technology Data Exchange (ETDEWEB)

Beer, Ambros J. [Technical University of Munich (TUM), Department of Nuclear Medicine, Klinikum rechts der Isar, Munich (Germany); Holzapfel, Konstantin; Settles, Marcus; Rummeny, Ernst J. [Technical University of Munich, Department of Radiology, Klinikum rechts der Isar, Munich (Germany); Neudorfer, Juliana; Kroenig, Holger; Peschel, Christian; Bernhard, Helga [TUM, Munich, Department of Hematology/Oncology, Klinikum rechts der Isar, Munich (Germany); Piontek, Guido; Schlegel, Juergen [TUM, Munich, Division of Neuropathology, Institute of Pathology, Klinikum rechts der Isar, Munich (Germany)

2008-06-15

New technologies are needed to characterize the migration and survival of antigen-specific T cells in vivo. In this study, we developed a novel technique for the labeling of human cytotoxic T lymphocytes with superparamagnetic iron-oxide particles and the subsequent depiction with a conventional 1.5-T magnetic resonance scanner. Antigen-specific CD8{sup +} T lymphocytes were labeled with ferucarbotran by lipofection. The uptake of ferucarbotran was confirmed by immunofluorescence microscopy using a dextran-specific antibody, and the intracellular enrichment of iron was measured by atomic absorption spectrometry. The imaging of T cells was performed by magnetic resonance on day 0, 2, 7 and 14 after the labeling procedure. On day 0 and 2 post labeling, a pronounced shortening of T2*-relaxation times was observed, which diminished after 7 days and was not detectable anymore after 14 days, probably due to the retained mitotic activity of the labeled T cells. Of importance, the antigen-specific cytolytic activity of the T cells was preserved following ferucarbotran labeling. Efficient ferucarbotran labeling of functionally active T lymphocytes and their detection by magnetic resonance imaging allows the in vivo monitoring of T cells and, subsequently, will impact the further development of T cell-based therapies. (orig.)

Visualization of antigen-specific human cytotoxic T lymphocytes labeled with superparamagnetic iron-oxide particles

International Nuclear Information System (INIS)

Beer, Ambros J.; Holzapfel, Konstantin; Settles, Marcus; Rummeny, Ernst J.; Neudorfer, Juliana; Kroenig, Holger; Peschel, Christian; Bernhard, Helga; Piontek, Guido; Schlegel, Juergen

2008-01-01

New technologies are needed to characterize the migration and survival of antigen-specific T cells in vivo. In this study, we developed a novel technique for the labeling of human cytotoxic T lymphocytes with superparamagnetic iron-oxide particles and the subsequent depiction with a conventional 1.5-T magnetic resonance scanner. Antigen-specific CD8 + T lymphocytes were labeled with ferucarbotran by lipofection. The uptake of ferucarbotran was confirmed by immunofluorescence microscopy using a dextran-specific antibody, and the intracellular enrichment of iron was measured by atomic absorption spectrometry. The imaging of T cells was performed by magnetic resonance on day 0, 2, 7 and 14 after the labeling procedure. On day 0 and 2 post labeling, a pronounced shortening of T2*-relaxation times was observed, which diminished after 7 days and was not detectable anymore after 14 days, probably due to the retained mitotic activity of the labeled T cells. Of importance, the antigen-specific cytolytic activity of the T cells was preserved following ferucarbotran labeling. Efficient ferucarbotran labeling of functionally active T lymphocytes and their detection by magnetic resonance imaging allows the in vivo monitoring of T cells and, subsequently, will impact the further development of T cell-based therapies. (orig.)

Acquired transcriptional programming in functional and exhausted virus-specific CD8 T cells.

Science.gov (United States)

Youngblood, Ben; Wherry, E John; Ahmed, Rafi

2012-01-01

Failure to control viral infections such as HIV results in T-cell receptor (TCR) and inhibitory receptor driven exhaustion of antigen-specific T cells. Persistent signaling by these receptors during chronic viral infection sculpts the transcriptional regulatory programs of virus-specific T cells. The resulting gene expression profile is tailored to temper the potentially damaging effector functions of cytotoxic T cells and adapt them to an antigen-rich and inflammation-rich environment. Here we review recent studies investigating mechanisms of transcriptional regulation of effector, functional memory, and exhausted T-cell functions during acute versus chronic infections. Patterns of gene expression in virus-specific CD8 T cells are a result of a combination of pro and inhibitory signals from antigen presentation (TCR-mediated) and co-inhibitory receptor ligation (PD-1, 2B4). Further, memory-specific transcriptional regulation of 2B4 expression and signaling impose a self-limiting secondary effector response to a prolonged viral infection. Additionally, differentiation of functional memory CD8 T cells is coupled with acquisition of a repressive epigenetic program for PD-1 expression. However, chronic infection provides a signal that blocks the acquisition of these epigenetic modifications reinforcing the suppression of cytotoxic lymphocyte (CTL) functions in exhausted cells. Current findings suggest that the mechanism(s) that delineate functional memory versus exhaustion are coupled with acquisition of transcriptional programs at the effector stage of differentiation, reinforced by cessation or persistence of TCR signaling.

Identification of Low- and High-Impact Hemagglutinin Amino Acid Substitutions That Drive Antigenic Drift of Influenza A(H1N1 Viruses.

Directory of Open Access Journals (Sweden)

William T Harvey

2016-04-01

Full Text Available Determining phenotype from genetic data is a fundamental challenge. Identification of emerging antigenic variants among circulating influenza viruses is critical to the vaccine virus selection process, with vaccine effectiveness maximized when constituents are antigenically similar to circulating viruses. Hemagglutination inhibition (HI assay data are commonly used to assess influenza antigenicity. Here, sequence and 3-D structural information of hemagglutinin (HA glycoproteins were analyzed together with corresponding HI assay data for former seasonal influenza A(H1N1 virus isolates (1997-2009 and reference viruses. The models developed identify and quantify the impact of eighteen amino acid substitutions on the antigenicity of HA, two of which were responsible for major transitions in antigenic phenotype. We used reverse genetics to demonstrate the causal effect on antigenicity for a subset of these substitutions. Information on the impact of substitutions allowed us to predict antigenic phenotypes of emerging viruses directly from HA gene sequence data and accuracy was doubled by including all substitutions causing antigenic changes over a model incorporating only the substitutions with the largest impact. The ability to quantify the phenotypic impact of specific amino acid substitutions should help refine emerging techniques that predict the evolution of virus populations from one year to the next, leading to stronger theoretical foundations for selection of candidate vaccine viruses. These techniques have great potential to be extended to other antigenically variable pathogens.

Identification of Low- and High-Impact Hemagglutinin Amino Acid Substitutions That Drive Antigenic Drift of Influenza A(H1N1) Viruses

Science.gov (United States)

Harvey, William T.; Benton, Donald J.; Gregory, Victoria; Hall, James P. J.; Daniels, Rodney S.; Bedford, Trevor; Haydon, Daniel T.; Hay, Alan J.; McCauley, John W.; Reeve, Richard

2016-01-01

Determining phenotype from genetic data is a fundamental challenge. Identification of emerging antigenic variants among circulating influenza viruses is critical to the vaccine virus selection process, with vaccine effectiveness maximized when constituents are antigenically similar to circulating viruses. Hemagglutination inhibition (HI) assay data are commonly used to assess influenza antigenicity. Here, sequence and 3-D structural information of hemagglutinin (HA) glycoproteins were analyzed together with corresponding HI assay data for former seasonal influenza A(H1N1) virus isolates (1997–2009) and reference viruses. The models developed identify and quantify the impact of eighteen amino acid substitutions on the antigenicity of HA, two of which were responsible for major transitions in antigenic phenotype. We used reverse genetics to demonstrate the causal effect on antigenicity for a subset of these substitutions. Information on the impact of substitutions allowed us to predict antigenic phenotypes of emerging viruses directly from HA gene sequence data and accuracy was doubled by including all substitutions causing antigenic changes over a model incorporating only the substitutions with the largest impact. The ability to quantify the phenotypic impact of specific amino acid substitutions should help refine emerging techniques that predict the evolution of virus populations from one year to the next, leading to stronger theoretical foundations for selection of candidate vaccine viruses. These techniques have great potential to be extended to other antigenically variable pathogens. PMID:27057693

Meta-analysis of the association between rumination and reduced autobiographical memory specificity.

Science.gov (United States)

Chiu, Connie P Y; Griffith, James W; Lenaert, Bert; Raes, Filip; Hermans, Dirk; Barry, Tom J

2018-05-16

The CaRFAX model, proposed by Williams J. M. G. (2006. Capture and rumination, functional avoidance, and executive control (CaRFAX): Three processes that underlie overgeneral memory. Cognition and Emotion, 20, 548-568. doi: 10.1080/02699930500450465 ; Williams, J. M. G., Barnhofer, T., Crane, C., Herman, D., Raes, F., Watkins, E., & Dalgleish, T. (2007). Autobiographical memory specificity and emotional disorder. Psychological Bulletin, 133(1), 122-148. doi: 10.1037/0033-2909.133.1.122 ) posits that reduced autobiographical memory specificity, a key factor associated with the emergence and maintenance of emotional disorders, may result from heightened rumination. We provide the first meta-analysis of the relation between autobiographical memory specificity and trait rumination. PsycINFO, PsycARTICLES and MEDLINE databases were searched and the following were extracted: the correlation between the number of specific memories recalled in the Autobiographical Memory Test and self-reported trait rumination scores, and its sub-factors - brooding and reflection. The pooled effect size for the correlation between memory specificity and trait rumination was small (d = -.05) and did not differ significantly from zero (p = .09). The effect sizes for the correlation with brooding and reflection were not significantly different from zero. There is limited support for the association between trait rumination and memory specificity suggested in CaRFAX.

Prostate-specific antigen and long-term prediction of prostate cancer incidence and mortality in the general population

DEFF Research Database (Denmark)

Ørsted, David Dynnes; Nordestgaard, Børge G; Jensen, Gorm B

2012-01-01

It is largely unknown whether prostate-specific antigen (PSA) level at first date of testing predicts long-term risk of prostate cancer (PCa) incidence and mortality in the general population.......It is largely unknown whether prostate-specific antigen (PSA) level at first date of testing predicts long-term risk of prostate cancer (PCa) incidence and mortality in the general population....

Specific and common antigens of Clonorchis sinensis and Opisthorchis viverrini (Opisthorchidae, Trematoda)

Science.gov (United States)

Choi, Min-Ho; Ryu, Jin-Sook; Lee, Mejeong; Li, Shunyu; Chung, Byung-Suk; Chai, Jong-Yil; Sithithaworn, Paiboon; Tesana, Smarn

2003-01-01

The antigenic characterizations and serological reactions of human liver flukes, Clonorchis sinensis and Opisthorchis viverrini, were analyzed by immunoblot. The antigenic profiles of the crude extract of Clonorchis contained major proteins of 8, 26-28, 34-37, 43, and 70 kDa, and those of Opisthorchis 34-37, 43, 70, and 100 kDa. Of these, the 8, 26-28 and 34-37 kDa bands of Clonorchis and the 100 kDa of Opisthorchis were major components of each excretory-secretory antigen. The 8 and 26-28 kDa bands were specific to Clonorchis but the 100 kDa of Opisthorchis cross-reacted with the sera of clonorchiasis, and the 34-37, 70 and 100 kDa bands cross-reacted with sera of other helminthiases. The frequency and intensity of the immunoblot reactions were positively correlated with the intensity of the liver fluke infection. PMID:12972729

Enhanced dimension-specific visual working memory in grapheme–color synesthesia☆

Science.gov (United States)

Terhune, Devin Blair; Wudarczyk, Olga Anna; Kochuparampil, Priya; Cohen Kadosh, Roi

2013-01-01

There is emerging evidence that the encoding of visual information and the maintenance of this information in a temporarily accessible state in working memory rely on the same neural mechanisms. A consequence of this overlap is that atypical forms of perception should influence working memory. We examined this by investigating whether having grapheme–color synesthesia, a condition characterized by the involuntary experience of color photisms when reading or representing graphemes, would confer benefits on working memory. Two competing hypotheses propose that superior memory in synesthesia results from information being coded in two information channels (dual-coding) or from superior dimension-specific visual processing (enhanced processing). We discriminated between these hypotheses in three n-back experiments in which controls and synesthetes viewed inducer and non-inducer graphemes and maintained color or grapheme information in working memory. Synesthetes displayed superior color working memory than controls for both grapheme types, whereas the two groups did not differ in grapheme working memory. Further analyses excluded the possibilities of enhanced working memory among synesthetes being due to greater color discrimination, stimulus color familiarity, or bidirectionality. These results reveal enhanced dimension-specific visual working memory in this population and supply further evidence for a close relationship between sensory processing and the maintenance of sensory information in working memory. PMID:23892185

Rapidly boosted Plasma IL-5 induced by treatment of human Schistosomiasis haematobium is dependent on antigen dose, IgE and eosinophils

DEFF Research Database (Denmark)

Wilson, Shona; Jones, Frances M.; Fofana, Hassan K. M.

2013-01-01

IgE specific to worm antigen (SWA) and pre-treatment eosinophil number, are associated with human immunity to re-infection with schistosomes after chemotherapeutic treatment. Treatment significantly elevates circulating IL-5 24-hr post-treatment of Schistosoma mansoni. Here we investigate...

Circulating Estradiol Regulates Brain-Derived Estradiol via Actions at GnRH Receptors to Impact Memory in Ovariectomized Rats.

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Nelson, Britta S; Black, Katelyn L; Daniel, Jill M

2016-01-01

Systemic estradiol treatment enhances hippocampus-dependent memory in ovariectomized rats. Although these enhancements are traditionally thought to be due to circulating estradiol, recent data suggest these changes are brought on by hippocampus-derived estradiol, the synthesis of which depends on gonadotropin-releasing hormone (GnRH) activity. The goal of the current work is to test the hypothesis that peripheral estradiol affects hippocampus-dependent memory through brain-derived estradiol regulated via hippocampal GnRH receptor activity. In the first experiment, intracerebroventricular infusion of letrozole, which prevents the synthesis of estradiol, blocked the ability of peripheral estradiol administration in ovariectomized rats to enhance hippocampus-dependent memory in a radial-maze task. In the second experiment, hippocampal infusion of antide, a long-lasting GnRH receptor antagonist, blocked the ability of peripheral estradiol administration in ovariectomized rats to enhance hippocampus-dependent memory. In the third experiment, hippocampal infusion of GnRH enhanced hippocampus-dependent memory, the effects of which were blocked by letrozole infusion. Results indicate that peripheral estradiol-induced enhancement of cognition is mediated by brain-derived estradiol via hippocampal GnRH receptor activity.

Protein structure of fetal antigen 1 (FA1). A novel circulating human epidermal-growth-factor-like protein expressed in neuroendocrine tumors and its relation to the gene products of dlk and pG2

DEFF Research Database (Denmark)

Jensen, Charlotte Harken; Krogh, Thomas N; Højrup, Peter

1994-01-01

The present paper describes the primary structure, glycosylation and tissue localization of fetal antigen 1 (FA1) isolated from second-trimester human amniotic fluid. FA1 is a single-chained, heterogeneous glycoprotein of 225-262 amino acid residues. FA1 has six well conserved epidermal...... extends with minor corrections to the human adrenal-specific mRNA, pG2 as well. Immunohistochemical analysis demonstrated the presence of FA1 in 10 out of 14 lung tumors containing neuroendocrine elements, and in the placental villi where FA1 was exclusively seen in stromal cells in close contact...... to the vascular structure. In the pancreas, FA1 co-localized with insulin in the insulin secretory granules of the beta cells within the islets of Langerhans. Our findings suggest that FA1 is synthesized as a membrane anchored protein and released into the circulation after enzymic cleavage, and that circulating...

Use of Digital Rectal Examination as an Adjunct to Prostate Specific Antigen in the Detection of Clinically Significant Prostate Cancer.

Science.gov (United States)

Halpern, Joshua A; Oromendia, Clara; Shoag, Jonathan E; Mittal, Sameer; Cosiano, Michael F; Ballman, Karla V; Vickers, Andrew J; Hu, Jim C

2018-04-01

Guidelines from the NCCN ® (National Comprehensive Cancer Network®) advocate digital rectal examination screening only in men with elevated prostate specific antigen. We investigated the effect of prostate specific antigen on the association of digital rectal examination and clinically significant prostate cancer in a large American cohort. We evaluated the records of the 35,350 men who underwent digital rectal examination in the screening arm of the Prostate, Lung, Colorectal and Ovarian Cancer Screening trial for the development of clinically significant prostate cancer (Gleason 7 or greater). Followup was 343,273 person-years. The primary outcome was the rate of clinically significant prostate cancer among men with vs without suspicious digital rectal examination. We performed competing risks regression to evaluate the interaction between time varying suspicious digital rectal examination and prostate specific antigen. A total of 1,713 clinically significant prostate cancers were detected with a 10-year cumulative incidence of 5.9% (95% CI 5.6-6.2). Higher risk was seen for suspicious vs nonsuspicious digital rectal examination. Increases in absolute risk were small and clinically irrelevant for normal (less than 2 ng/ml) prostate specific antigen (1.5% vs 0.7% risk of clinically significant prostate cancer at 10 years), clinically relevant for elevated (3 ng/ml or greater) prostate specific antigen (23.0% vs 13.7%) and modestly clinically relevant for equivocal (2 to 3 ng/ml) prostate specific antigen (6.5% vs 3.5%). Digital rectal examination demonstrated prognostic usefulness when prostate specific antigen was greater than 3 ng/ml, limited usefulness for less than 2 ng/ml and marginal usefulness for 2 to 3 ng/ml. These findings support the restriction of digital rectal examination to men with higher prostate specific antigen as a reflex test to improve specificity. It should not be used as a primary screening modality to improve sensitivity. Copyright �

Development and evaluation of tailored specific real-time RT-PCR assays for detection of foot-and-mouth disease virus serotypes circulating in East Africa

DEFF Research Database (Denmark)

Bachanek-Bankowska, Katarzyna; Mero, Herieth R.; Wadsworth, Jemma

2016-01-01

Rapid, reliable and accurate diagnostic methods provide essential support to programmes that monitor and control foot-and-mouth disease (FMD). While pan-specific molecular tests for FMD virus (FMDV) detection are well established and widely used in endemic and FMD-free countries, current serotyping...... methods mainly rely either on antigen detection ELISAs or nucleotide sequencing approaches. This report describes the development of a panel of serotype-specific real-time RT-PCR assays (rRT-PCR) tailored to detect FMDV lineages currently circulating in East Africa. These assays target sequences within...... sequencing. Samples (n = 71) representing serotype A (topotype AFRICA, lineage G-I), serotype O (topotypes EA-2 and EA-4), serotype SAT 1 (topotype I (NWZ)) and serotype SAT2 (topotype IV) were correctly identified with these rRT-PCR assays. Furthermore, FMDV RNA from samples that did not contain infectious...

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

DEFF Research Database (Denmark)

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

2016-01-01

-major histocompatibility complex (MHC) multimers labeled with individual DNA barcodes to screen >1,000 peptide specificities in a single sample, and detect low-frequency CD8 T cells specific for virus- or cancer-restricted antigens. When analyzing T-cell recognition of shared melanoma antigens before and after adoptive...... cell therapy in melanoma patients, we observe a greater number of melanoma-specific T-cell populations compared with cytometry-based approaches. Furthermore, we detect neoepitope-specific T cells in tumor-infiltrating lymphocytes and peripheral blood from patients with non-small cell lung cancer...

Stimulus-specific suppression preserves information in auditory short-term memory.

Science.gov (United States)

Linke, Annika C; Vicente-Grabovetsky, Alejandro; Cusack, Rhodri

2011-08-02

Philosophers and scientists have puzzled for millennia over how perceptual information is stored in short-term memory. Some have suggested that early sensory representations are involved, but their precise role has remained unclear. The current study asks whether auditory cortex shows sustained frequency-specific activation while sounds are maintained in short-term memory using high-resolution functional MRI (fMRI). Investigating short-term memory representations within regions of human auditory cortex with fMRI has been difficult because of their small size and high anatomical variability between subjects. However, we overcame these constraints by using multivoxel pattern analysis. It clearly revealed frequency-specific activity during the encoding phase of a change detection task, and the degree of this frequency-specific activation was positively related to performance in the task. Although the sounds had to be maintained in memory, activity in auditory cortex was significantly suppressed. Strikingly, patterns of activity in this maintenance period correlated negatively with the patterns evoked by the same frequencies during encoding. Furthermore, individuals who used a rehearsal strategy to remember the sounds showed reduced frequency-specific suppression during the maintenance period. Although negative activations are often disregarded in fMRI research, our findings imply that decreases in blood oxygenation level-dependent response carry important stimulus-specific information and can be related to cognitive processes. We hypothesize that, during auditory change detection, frequency-specific suppression protects short-term memory representations from being overwritten by inhibiting the encoding of interfering sounds.

Outcome of limbic encephalitis with VGKC-complex antibodies: relation to antigenic specificity.

Science.gov (United States)

Malter, M P; Frisch, C; Schoene-Bake, J C; Helmstaedter, C; Wandinger, K P; Stoecker, W; Urbach, H; Surges, R; Elger, C E; Vincent, A V; Bien, C G

2014-09-01

In limbic encephalitis (LE) with antibodies (Abs) to the voltage-gated potassium channel complex (VGKC), the Abs are mainly directed to the VGKC-complex proteins, leucine-rich, glioma inactivated 1 protein (LGI1) or contactin-associated protein-like 2 (CASPR-2) or neither. Here, we relate the outcomes of VGKC-LE patients to the presence of Abs to LGI1, CASPR-2 or neither antigen (LGI1/CASPR-2-Ab(-)). Clinical, neuropsychology and MRI data were obtained from patient records for all LE patients from the Bonn Epilepsy Centre positive for VGKC-Abs by radioimmunoprecipitation assay between 2002 and 2011. Eighteen VGKC-LE patients were identified: nine patients (50 %) had LGI1-Abs, three (16 %) had CASPR-2-Abs; and six (33 %) were negative for both LGI1- and CASPR-2-Abs. At first assessment, the groups did not differ clinically or radiologically, but faciobrachial dystonic seizures were only observed in two LGI1-Ab(+) patients. All patients received monthly intravenous methylprednisolone (MP) pulses. At the most recent follow up (median 26 months), thirteen (72 %) were seizure-free, and seizure-freedom rates did not differ between the Ab groups. Hippocampal atrophy had developed in 7/9 LGI1-Ab(+) patients, but in none of the CASPR-2-Ab(+) or LGI/CASPR-2-Ab(-) patients (p = 0.003). While all subgroups improved, memory scores only normalized in six patients (33 %) and LGI1-Ab(+) patients were left with significantly poorer memory than the other two subgroups. Most VGKC-LE patients become seizure-free with pulsed monthly MP, but memory outcome is less favourable. Hippocampal atrophy and poor memory recovery is common in patients with LGI1-Abs and suggests permanent functional damage. More intense immunotherapies could improve outcomes in LGI1-Ab(+)-LE.

Early transduction produces highly functional chimeric antigen receptor-modified virus-specific T-cells with central memory markers: a Production Assistant for Cell Therapy (PACT) translational application

OpenAIRE

Sun, Jiali; Huye, Leslie E; Lapteva, Natalia; Mamonkin, Maksim; Hiregange, Manasa; Ballard, Brandon; Dakhova, Olga; Raghavan, Darshana; Durett, April G; Perna, Serena K; Omer, Bilal; Rollins, Lisa A; Leen, Ann M; Vera, Juan F; Dotti, Gianpietro

2015-01-01

Background Virus-specific T-cells (VSTs) proliferate exponentially after adoptive transfer into hematopoietic stem cell transplant (HSCT) recipients, eliminate virus infections, then persist and provide long-term protection from viral disease. If VSTs behaved similarly when modified with tumor-specific chimeric antigen receptors (CARs), they should have potent anti-tumor activity. This theory was evaluated by Cruz et al. in a previous clinical trial with CD19.CAR-modified VSTs, but there was ...

Poly-functional and long-lasting anticancer immune response elicited by a safe attenuated Pseudomonas aeruginosa vector for antigens delivery

Directory of Open Access Journals (Sweden)

Xavier Chauchet

2016-01-01

Full Text Available Live-attenuated bacterial vectors for antigens delivery have aroused growing interest in the field of cancer immunotherapy. Their potency to stimulate innate immunity and to promote intracellular antigen delivery into antigen-presenting cells could be exploited to elicit a strong and specific cellular immune response against tumor cells. We previously described genetically-modified and attenuated Pseudomonas aeruginosa vectors able to deliver in vivo protein antigens into antigen-presenting cells, through Type 3 secretion system of the bacteria. Using this approach, we managed to protect immunized mice against aggressive B16 melanoma development in both a prophylactic and therapeutic setting. In this study, we further investigated the antigen-specific CD8+ T cell response, in terms of phenotypic and functional aspects, obtained after immunizations with a killed but metabolically active P. aeruginosa attenuated vector. We demonstrated that P. aeruginosa vaccine induces a highly functional pool of antigen-specific CD8+ T cell able to infiltrate the tumor. Furthermore, multiple immunizations allowed the development of a long-lasting immune response, represented by a pool of predominantly effector memory cells which protected mice against late tumor challenge. Overall, killed but metabolically active P. aeruginosa vector is a safe and promising approach for active and specific antitumor immunotherapy.

Prolonged antigen presentation is required for optimal CD8+ T cell responses against malaria liver stage parasites.

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Ian A Cockburn

2010-05-01

Full Text Available Immunization with irradiated sporozoites is currently the most effective vaccination strategy against liver stages of malaria parasites, yet the mechanisms underpinning the success of this approach are unknown. Here we show that the complete development of protective CD8+ T cell responses requires prolonged antigen presentation. Using TCR transgenic cells specific for the malaria circumsporozoite protein, a leading vaccine candidate, we found that sporozoite antigen persists for over 8 weeks after immunization--a remarkable finding since irradiated sporozoites are incapable of replication and do not differentiate beyond early liver stages. Persisting antigen was detected in lymphoid organs and depends on the presence of CD11c+ cells. Prolonged antigen presentation enhanced the magnitude of the CD8+ T cell response in a number of ways. Firstly, reducing the time primed CD8+ T cells were exposed to antigen in vivo severely reduced the final size of the developing memory population. Secondly, fully developed memory cells expanded in previously immunized mice but not when transferred to naïve animals. Finally, persisting antigen was able to prime naïve cells, including recent thymic emigrants, to become functional effector cells capable of eliminating parasites in the liver. Together these data show that the optimal development of protective CD8+ T cell immunity against malaria liver stages is dependent upon the prolonged presentation of sporozoite-derived antigen.

Application of Adoptive T-Cell Therapy Using Tumor Antigen-Specific T-Cell Receptor Gene Transfer for the Treatment of Human Leukemia

Directory of Open Access Journals (Sweden)

Toshiki Ochi

2010-01-01

Full Text Available The last decade has seen great strides in the field of cancer immunotherapy, especially the treatment of melanoma. Beginning with the identification of cancer antigens, followed by the clinical application of anti-cancer peptide vaccination, it has now been proven that adoptive T-cell therapy (ACT using cancer antigen-specific T cells is the most effective option. Despite the apparent clinical efficacy of ACT, the timely preparation of a sufficient number of cancer antigen-specific T cells for each patient has been recognized as its biggest limitation. Currently, therefore, attention is being focused on ACT with engineered T cells produced using cancer antigen-specific T-cell receptor (TCR gene transfer. With regard to human leukemia, ACT using engineered T cells bearing the leukemia antigen-specific TCR gene still remains in its infancy. However, several reports have provided preclinical data on TCR gene transfer using Wilms' tumor gene product 1 (WT1, and also preclinical and clinical data on TCR gene transfer involving minor histocompatibility antigen, both of which have been suggested to provide additional clinical benefit. In this review, we examine the current status of anti-leukemia ACT with engineered T cells carrying the leukemia antigen-specific TCR gene, and discuss the existing barriers to progress in this area.

Marked differences in human melanoma antigen-specific T cell responsiveness after vaccination using a functional microarray.

Directory of Open Access Journals (Sweden)

Daniel S Chen

2005-10-01

Full Text Available In contrast to many animal model studies, immunotherapeutic trials in humans suffering from cancer invariably result in a broad range of outcomes, from long-lasting remissions to no discernable effect.In order to study the T cell responses in patients undergoing a melanoma-associated peptide vaccine trial, we have developed a high-throughput method using arrays of peptide-major histocompatibility complexes (pMHC together with antibodies against secreted factors. T cells were specifically immobilized and activated by binding to particular pMHCs. The antibodies, spotted together with the pMHC, specifically capture cytokines secreted by the T cells. This technique allows rapid, simultaneous isolation and multiparametric functional characterization of antigen-specific T cells present in clinical samples. Analysis of CD8+ lymphocytes from ten melanoma patients after peptide vaccination revealed a diverse set of patient- and antigen-specific profiles of cytokine secretion, indicating surprising differences in their responsiveness. Four out of four patients who showed moderate or greater secretion of both interferon-gamma (IFNgamma and tumor necrosis factor-alpha (TNFalpha in response to a gp100 antigen remained free of melanoma recurrence, whereas only two of six patients who showed discordant secretion of IFNgamma and TNFalpha did so.Such multiparametric analysis of T cell antigen specificity and function provides a valuable tool with which to dissect the molecular underpinnings of immune responsiveness and how this information correlates with clinical outcome.

Autobiographical memory specificity in response to verbal and pictorial cues in clinical depression.

Science.gov (United States)

Ridout, Nathan; Dritschel, Barbara; Matthews, Keith; O'Carroll, Ronan

2016-06-01

Depressed individuals have been consistently shown to exhibit problems in accessing specific memories of events from their past and instead tend to retrieve categorical summaries of events. The majority of studies examining autobiographical memory changes associated with psychopathology have tended to use word cues, but only one study to date has used images (with PTSD patients). to determine if using images to cue autobiographical memories would reduce the memory specificity deficit exhibited by patients with depression in comparison to healthy controls. Twenty-five clinically depressed patients and twenty-five healthy controls were assessed on two versions of the autobiographical memory test; cued with emotional words and images. Depressed patients retrieved significantly fewer specific memories, and a greater number of categorical, than did the controls. Controls retrieved a greater proportion of specific memories to images compared to words, whereas depressed patients retrieved a similar proportion of specific memories to both images and words. no information about the presence and severity of past trauma was collected. results suggest that the overgeneral memory style in depression generalises from verbal to pictorial cues. This is important because retrieval to images may provide a more ecologically valid test of everyday memory experiences than word-cued retrieval.. Copyright © 2016 Elsevier Ltd. All rights reserved.

A specific role for the human amygdala in olfactory memory.

Science.gov (United States)

Buchanan, Tony W; Tranel, Daniel; Adolphs, Ralph

2003-01-01

The medial temporal lobe is known to play a role in the processing of olfaction and memory. The specific contribution of the human amygdala to memory for odors has not been addressed, however. The role of this region in memory for odors was assessed in patients with unilateral amygdala damage due to temporal lobectomy (n = 20; 11 left, 9 right), one patient with selective bilateral amygdala damage, and in 20 age-matched normal controls. Fifteen odors were presented, followed 1 h later by an odor-name matching test and an odor-odor recognition test. Signal detection analyses showed that both unilateral groups were impaired in their memory for matching odors with names, these patients were not significantly impaired on odor-odor recognition. Bilateral amygdala damage resulted in severe impairment in both odor-name matching as well as in odor-odor recognition memory. Importantly, none of the patients were impaired on an auditory verbal learning task, suggesting that these findings reflect a specific impairment in olfactory memory, and not merely a more general memory deficit. Taken together, the data provide neuropsychological evidence that the human amygdala is essential for olfactory memory.

Pathological Outcome following Radical Prostatectomy in Men with Prostate Specific Antigen Greater than 10 ng/ml and Histologically Favorable Risk Prostate Cancer.

Science.gov (United States)

Yu, Jiwoong; Kwon, Young Suk; Kim, Sinae; Han, Christopher Sejong; Farber, Nicholas; Kim, Jongmyung; Byun, Seok Soo; Kim, Wun-Jae; Jeon, Seong Soo; Kim, Isaac Yi

2016-05-01

Active surveillance is now the treatment of choice in men with low risk prostate cancer. Although there is no consensus on which patients are eligible for active surveillance, prostate specific antigen above 10 ng/ml is generally excluded. In an attempt to determine the validity of using a prostate specific antigen cutoff of 10 ng/ml to counsel men considering active surveillance we analyzed a multi-institution database to determine the pathological outcome in men with prostate specific antigen greater than 10 ng/ml but histologically favorable risk prostate cancer. We queried a prospectively maintained database of men with histologically favorable risk prostate cancer who underwent radical prostatectomy between 2003 and 2015. The cohort was categorized into 3 groups based on prostate specific antigen level, including low-less than 10 ng/ml, intermediate-10 or greater to less than 20 and high-20 or greater. Associations of prostate specific antigen group with adverse pathological and oncologic outcomes were analyzed. Of 2,125 patients 1,327 were categorized with histologically favorable risk disease. However on multivariate analyses the rates of up staging and upgrading were similar between the intermediate and low prostate specific antigen groups. In contrast compared to the intermediate prostate specific antigen group the high group had higher incidences of up staging (p = 0.02) and upgrading to 4 + 3 or greater disease (p = 0.046). Biochemical recurrence-free survival rates revealed no pairwise intergroup differences except between the low and high groups. Patients with preoperatively elevated prostate specific antigen between 10 and less than 20 ng/ml who otherwise had histologically favorable risk prostate cancer were not at higher risk for adverse pathological outcomes than men with prostate specific antigen less than 10 ng/ml. Copyright © 2016 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Synthetic oligonucleotide antigens modified with locked nucleic acids detect disease specific antibodies

DEFF Research Database (Denmark)

Samuelsen, Simone V; Solov'yov, Ilia A.; Balboni, Imelda M.

2016-01-01

New techniques to detect and quantify antibodies to nucleic acids would provide a significant advance over current methods, which often lack specificity. We investigate the potential of novel antigens containing locked nucleic acids (LNAs) as targets for antibodies. Particularly, employing...... molecular dynamics we predict optimal nucleotide composition for targeting DNA-binding antibodies. As a proof of concept, we address a problem of detecting anti-DNA antibodies that are characteristic of systemic lupus erythematosus, a chronic autoimmune disease with multiple manifestations. We test the best...... that the novel method is a promising tool to create antigens for research and point-of-care monitoring of anti-DNA antibodies....

Preschoolers' Autobiographical Memory Specificity Relates to Their Emotional Adjustment

Science.gov (United States)

Valentino, Kristin; McDonnell, Christina G.; Comas, Michelle; Nuttall, Amy K.

2018-01-01

Reduced autobiographical memory specificity (AMS) has robust associations with psychopathology. As such, understanding the development of AMS (or its inverse, overgeneral autobiographical memory) and how it may be unique from other aspects of memory performance is important. In particular, it is unclear whether child AMS is distinct from…

Carcinoma-associated antigens

International Nuclear Information System (INIS)

Bartorelli, A.; Accinni, R.

1981-01-01

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

Enhanced dimension-specific visual working memory in grapheme-color synesthesia.

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Terhune, Devin Blair; Wudarczyk, Olga Anna; Kochuparampil, Priya; Cohen Kadosh, Roi

2013-10-01

There is emerging evidence that the encoding of visual information and the maintenance of this information in a temporarily accessible state in working memory rely on the same neural mechanisms. A consequence of this overlap is that atypical forms of perception should influence working memory. We examined this by investigating whether having grapheme-color synesthesia, a condition characterized by the involuntary experience of color photisms when reading or representing graphemes, would confer benefits on working memory. Two competing hypotheses propose that superior memory in synesthesia results from information being coded in two information channels (dual-coding) or from superior dimension-specific visual processing (enhanced processing). We discriminated between these hypotheses in three n-back experiments in which controls and synesthetes viewed inducer and non-inducer graphemes and maintained color or grapheme information in working memory. Synesthetes displayed superior color working memory than controls for both grapheme types, whereas the two groups did not differ in grapheme working memory. Further analyses excluded the possibilities of enhanced working memory among synesthetes being due to greater color discrimination, stimulus color familiarity, or bidirectionality. These results reveal enhanced dimension-specific visual working memory in this population and supply further evidence for a close relationship between sensory processing and the maintenance of sensory information in working memory. Copyright © 2013 The Authors. Published by Elsevier B.V. All rights reserved.

Sensitivity, Specificity, and Positivity Predictors of the Pneumococcal Urinary Antigen Test in Community-Acquired Pneumonia.

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Molinos, Luis; Zalacain, Rafael; Menéndez, Rosario; Reyes, Soledad; Capelastegui, Alberto; Cillóniz, Catia; Rajas, Olga; Borderías, Luis; Martín-Villasclaras, Juan J; Bello, Salvador; Alfageme, Inmaculada; Rodríguez de Castro, Felipe; Rello, Jordi; Ruiz-Manzano, Juan; Gabarrús, Albert; Musher, Daniel M; Torres, Antoni

2015-10-01

Detection of the C-polysaccharide of Streptococcus pneumoniae in urine by an immune-chromatographic test is increasingly used to evaluate patients with community-acquired pneumonia. We assessed the sensitivity and specificity of this test in the largest series of cases to date and used logistic regression models to determine predictors of positivity in patients hospitalized with community-acquired pneumonia. We performed a multicenter, prospective, observational study of 4,374 patients hospitalized with community-acquired pneumonia. The urinary antigen test was done in 3,874 cases. Pneumococcal infection was diagnosed in 916 cases (21%); 653 (71%) of these cases were diagnosed exclusively by the urinary antigen test. Sensitivity and specificity were 60 and 99.7%, respectively. Predictors of urinary antigen positivity were female sex; heart rate≥125 bpm, systolic blood pressureantibiotic treatment; pleuritic chest pain; chills; pleural effusion; and blood urea nitrogen≥30 mg/dl. With at least six of all these predictors present, the probability of positivity was 52%. With only one factor present, the probability was only 12%. The urinary antigen test is a method with good sensitivity and excellent specificity in diagnosing pneumococcal pneumonia, and its use greatly increased the recognition of community-acquired pneumonia due to S. pneumoniae. With a specificity of 99.7%, this test could be used to direct simplified antibiotic therapy, thereby avoiding excess costs and risk for bacterial resistance that result from broad-spectrum antibiotics. We also identified predictors of positivity that could increase suspicion for pneumococcal infection or avoid the unnecessary use of this test.

Advances in prostate-specific membrane antigen PET of prostate cancer.

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Bouchelouche, Kirsten; Choyke, Peter L

2018-05-01

In recent years, a large number of reports have been published on prostate-specific membrane antigen (PSMA)/PET in prostate cancer (PCa). This review highlights advances in PSMA PET in PCa during the past year. PSMA PET/computed tomography (CT) is useful in detection of biochemical recurrence, especially at low prostate-specific antigen (PSA) values. The detection rate of PSMA PET is influenced by PSA level. For primary PCa, PSMA PET/CT shows promise for tumour localization in the prostate, especially in combination with multiparametric MRI (mpMRI). For primary staging, PSMA PET/CT can be used in intermediate and high-risk PCa. Intraoperative PSMA radioligand guidance seems promising for detection of malignant lymph nodes. While the use of PSMA PET/MRI in primary localized disease is limited to high and intermediate-risk patients and localized staging, in the recurrence setting, PET/MRI can be particularly helpful when the lesions are subtle. PSMA PET/CT is superior to choline PET/CT and other conventional imaging modalities. Molecular imaging with PSMA PET continues to pave the way for personalized medicine in PCa.However, large prospective clinical studies are still needed to fully evaluate the role of PSMA PET/CT and PET/MRI in the clinical workflow of PCa.

Prostate-Specific Antigen Mass and Free Prostate-Specific Antigen Mass for Predicting the Prostate Volume of Korean Men With Biopsy-Proven Benign Prostatic Hyperplasia

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Park, Tae Yong; Chae, Ji Yun; Kim, Jong Wook; Kim, Jin Wook; Oh, Mi Mi; Yoon, Cheol Yong; Moon, Du Geon

2013-01-01

Purpose It has been reported that prostate-specific antigen (PSA) correlates with prostate volume. Recently, some studies have reported that PSA mass (PSA adjusted for plasma volume) is more accurate than PSA at predicting prostate volume. In this study, we analyzed the accuracy of PSA and the related parameters of PSA mass, free PSA (fPSA), and fPSA mass in predicting prostate volume. Materials and Methods We retrospectively investigated 658 patients who underwent prostate biopsy from 2006 t...

Antigen processing of glycoconjugate vaccines; the polysaccharide portion of the pneumococcal CRM(197) conjugate vaccine co-localizes with MHC II on the antigen processing cell surface.

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Lai, Zengzu; Schreiber, John R

2009-05-21

Pneumococcal (Pn) polysaccharides (PS) are T-independent (TI) antigens and do not induce immunological memory or antibodies in infants. Conjugation of PnPS to the carrier protein CRM(197) induces PS-specific antibody in infants, and memory similar to T-dependent (Td) antigens. Conjugates have improved immunogenicity via antigen processing and presentation of carrier protein with MHC II and recruitment of T cell help, but the fate of the PS attached to the carrier is unknown. To determine the location of the PS component of PnPS-CRM(197) in the APC, we separately labeled PS and protein and tracked their location. The PS of types 14-CRM(197) and 19F-CRM(197) was specifically labeled by Alexa Fluor 594 hydrazide (red). The CRM(197) was separately labeled red in a reaction that did not label PS. Labeled antigens were incubated with APC which were fixed, permeabilized and incubated with anti-MHC II antibody labeled green by Alexa Fluor 488, followed by confocal microscopy. Labeled CRM(197) was presented on APC surface and co-localized with MHC II (yellow). Labeled unconjugated 14 or 19F PS did not go to the APC surface, but PS labeled 14-CRM(197) and 19F-CRM(197) was internalized and co-localized with MHC II. Monoclonal antibody to type 14 PS bound to intracellular type 14 PS and PS-CRM(197). Brefeldin A and chloroquine blocked both CRM(197) and PS labeled 14-CRM(197) and 19F-CRM(197) from co-localizing with MHC II. These data suggest that the PS component of the CRM(197) glycoconjugate enters the endosome, travels with CRM(197) peptides to the APC surface and co-localizes with MHC II.

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

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Hao Hong

Full Text Available 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.

Immune memory in invertebrates.

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Milutinović, Barbara; Kurtz, Joachim

2016-08-01

Evidence for innate immune memory (or 'priming') in invertebrates has been accumulating over the last years. We here provide an in-depth review of the current state of evidence for immune memory in invertebrates, and in particular take a phylogenetic viewpoint. Invertebrates are a very heterogeneous group of animals and accordingly, evidence for the phenomenon of immune memory as well as the hypothesized molecular underpinnings differ largely for the diverse invertebrate taxa. The majority of research currently focuses on Arthropods, while evidence from many other groups of invertebrates is fragmentary or even lacking. We here concentrate on immune memory that is induced by pathogenic challenges, but also extent our view to a non-pathogenic context, i.e. allograft rejection, which can also show forms of memory and can inform us about general principles of specific self-nonself recognition. We discuss definitions of immune memory and a number of relevant aspects such as the type of antigens used, the route of exposure, and the kinetics of reactions following priming. Copyright © 2016 Elsevier Ltd. All rights reserved.

Specificity in autobiographical memory narratives correlates with performance on the Autobiographical Memory Test and prospectively predicts depressive symptoms

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Sumner, Jennifer A.; Mineka, Susan; McAdams, Dan P.

2012-01-01

Reduced autobiographical memory specificity (AMS) is an important cognitive marker in depression that is typically measured with the Autobiographical Memory Test (AMT; Williams & Broadbent, 1986). The AMT is widely used, but the overreliance on a single methodology for assessing AMS is a limitation in the field. The current study investigated memory narratives as an alternative measure of AMS in an undergraduate student sample selected for being high or low on a measure of depressive symptoms (N = 55). We employed a multi-method design to compare narrative- and AMT-based measures of AMS. Participants generated personally significant self-defining memory narratives, and also completed two versions of the AMT (with and without instructions to retrieve specific memories). Greater AMS in self-defining memory narratives correlated with greater AMS in performance on both versions of the AMT in the full sample, and the patterns of relationships between the different AMS measures were generally similar in low and high dysphoric participants. Furthermore, AMS in self-defining memory narratives was prospectively associated with depressive symptom levels. Specifically, greater AMS in self-defining memory narratives predicted fewer depressive symptoms at a 10-week follow-up over and above baseline symptom levels. Implications for future research and clinical applications are discussed. PMID:23240988

Role of prostate specific antigen and immediate confirmatory biopsy in predicting progression during active surveillance for low risk prostate cancer.

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Adamy, Ari; Yee, David S; Matsushita, Kazuhito; Maschino, Alexandra; Cronin, Angel; Vickers, Andrew; Guillonneau, Bertrand; Scardino, Peter T; Eastham, James A

2011-02-01

We evaluated predictors of progression after starting active surveillance, especially the role of prostate specific antigen and immediate confirmatory prostate biopsy. A total of 238 men with prostate cancer met active surveillance eligibility criteria and were analyzed for progression with time. Cox proportional hazards regression was used to evaluate predictors of progression. Progression was evaluated using 2 definitions, including no longer meeting 1) full and 2) modified criteria, excluding prostate specific antigen greater than 10 ng/ml as a criterion. Using full criteria 61 patients progressed during followup. The 2 and 5-year progression-free probability was 80% and 60%, respectively. With prostate specific antigen included in progression criteria prostate specific antigen at confirmatory biopsy (HR 1.29, 95% CI 1.14-1.46, p <0.0005) and positive confirmatory biopsy (HR 1.75, 95% CI 1.01-3.04, p = 0.047) were independent predictors of progression. Of the 61 cases 34 failed due to increased prostate specific antigen, including only 5 with subsequent progression by biopsy criteria. When prostate specific antigen was excluded from progression criteria, only 32 cases progressed, and 2 and 5-year progression-free probability was 91% and 76%, respectively. Using modified criteria as an end point positive confirmatory biopsy was the only independent predictor of progression (HR 3.16, 95% CI 1.41-7.09, p = 0.005). Active surveillance is feasible in patients with low risk prostate cancer and most patients show little evidence of progression within 5 years. There is no clear justification for treating patients in whom prostate specific antigen increases above 10 ng/ml in the absence of other indications of tumor progression. Patients considering active surveillance should undergo confirmatory biopsy to better assess the risk of progression. Copyright © 2011 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Specific memory impairment following neonatal encephalopathy in term-born children.

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van Handel, Mariëlle; de Sonneville, Leo; de Vries, Linda S; Jongmans, Marian J; Swaab, Hanna

2012-01-01

This study examines short-term memory, verbal working memory, episodic long-term memory, and intelligence in 32 children with mild neonatal encephalopathy (NE), 39 children with moderate NE, 10 children with NE who developed cerebral palsy (CP), and 53 comparison children, at the age of 9 to 10 years. in addition to a global effect on intelligence, NE had a specific effect on verbal working memory, verbal and visuo-spatial long-term memory, and learning, which was associated with degree of NE. Although these memory problems occurred in children without CP, they were more pronounced when children had also developed CP.

Phenotype of Antigen Unexperienced TH Cells in the Inflamed Central Nervous System in Experimental Autoimmune Encephalomyelitis.

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Franck, Sophia; Paterka, Magdalena; Birkenstock, Jerome; Zipp, Frauke; Siffrin, Volker; Witsch, Esther

2017-06-01

Multiple sclerosis is a chronic, disseminated inflammation of the central nervous system which is thought to be driven by autoimmune T cells. Genetic association studies in multiple sclerosis and a large number of studies in the animal model of the disease support a role for effector/memory T helper cells. However, the mechanisms underlying relapses, remission and chronic progression in multiple sclerosis or the animal model experimental autoimmune encephalomyelitis, are not clear. In particular, there is only scarce information on the role of central nervous system-invading naive T helper cells in these processes. By applying two-photon laser scanning microscopy we could show in vivo that antigen unexperienced T helper cells migrated into the deep parenchyma of the inflamed central nervous system in experimental autoimmune encephalomyelitis, independent of their antigen specificity. Using flow cytometric analyses of central nervous system-derived lymphocytes we found that only antigen-specific, formerly naive T helper cells became activated during inflammation of the central nervous system encountering their corresponding antigen.

Working, declarative and procedural memory in specific language impairment

OpenAIRE

Lum, Jarrad A.G.; Conti-Ramsden, Gina; Page, Debra; Ullman, Michael T.

2012-01-01

According to the Procedural Deficit Hypothesis (PDH), abnormalities of brain structures underlying procedural memory largely explain the language deficits in children with specific language impairment (SLI). These abnormalities are posited to result in core deficits of procedural memory, which in turn explain the grammar problems in the disorder. The abnormalities are also likely to lead to problems with other, non-procedural functions, such as working memory, that rely at least partly on the...

Sleep deprivation specifically impairs short-term olfactory memory in Drosophila.

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Li, Xinjian; Yu, Feng; Guo, Aike

2009-11-01

Sleep is crucial to memory consolidation in humans and other animals; however, the effect of insufficient sleep on subsequent learning and memory remains largely elusive. Learning and memory after 1-day sleep deprivation (slpD) was evaluated using Pavlovian olfactory conditioning in Drosophila, and locomotor activity was measured using the Drosophila Activity Monitoring System in a 12:12 light-dark cycle. We found that slpD specifically impaired 1-h memory in wild type Canton-S flies, and this effect could persist for at least 2 h. However, alternative stresses (heat stress, oxidative stress, starvation, and rotation stress) did not result in a similar effect and left the flies' memory intact. Mechanistic studies demonstrated that flies with either silenced transmission of the mushroom body (MB) during slpD or down-regulated cAMP levels in the MB demonstrated no slpD-induced 1-h memory impairment. We found that slpD specifically impaired 1-h memory in Drosophila, and either silencing of MB transmission during slpD or down-regulation of the cAMP level in the MB protected the flies from slpD-induced impairment.

Limited transplantation of antigen-expressing hematopoietic stem cells induces long-lasting cytotoxic T cell responses.

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Warren L Denning

2011-02-01

Full Text Available Harnessing the ability of cytotoxic T lymphocytes (CTLs to recognize and eradicate tumor or pathogen-infected cells is a critical goal of modern immune-based therapies. Although multiple immunization strategies efficiently induce high levels of antigen-specific CTLs, the initial increase is typically followed by a rapid contraction phase resulting in a sharp decline in the frequency of functional CTLs. We describe a novel approach to immunotherapy based on a transplantation of low numbers of antigen-expressing hematopoietic stem cells (HSCs following nonmyeloablative or partially myeloablative conditioning. Continuous antigen presentation by a limited number of differentiated transgenic hematopoietic cells results in an induction and prolonged maintenance of fully functional effector T cell responses in a mouse model. Recipient animals display high levels of antigen-specific CTLs four months following transplantation in contrast to dendritic cell-immunized animals in which the response typically declines at 4-6 weeks post-immunization. Majority of HSC-induced antigen-specific CD8+ T cells display central memory phenotype, efficiently kill target cells in vivo, and protect recipients against tumor growth in a preventive setting. Furthermore, we confirm previously published observation that high level engraftment of antigen-expressing HSCs following myeloablative conditioning results in tolerance and an absence of specific cytotoxic activity in vivo. In conclusion, the data presented here supports potential application of immunization by limited transplantation of antigen-expressing HSCs for the prevention and treatment of cancer and therapeutic immunization of chronic infectious diseases such as HIV-1/AIDS.

Simultaneous targeting of prostate stem cell antigen and prostate-specific membrane antigen improves the killing of prostate cancer cells using a novel modular T cell-retargeting system.

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Arndt, Claudia; Feldmann, Anja; Koristka, Stefanie; Cartellieri, Marc; Dimmel, Maria; Ehninger, Armin; Ehninger, Gerhard; Bachmann, Michael

2014-09-01

Recently, we described a novel modular platform technology in which T cell-recruitment and tumor-targeting domains of conventional bispecific antibodies are split to independent components, a universal effector module (EM) and replaceable monospecific/monovalent target modules (TMs) that form highly efficient T cell-retargeting complexes. Theoretically, our unique strategy should allow us to simultaneously retarget T cells to different tumor antigens by combining the EM with two or more different monovalent/monospecific TMs or even with bivalent/bispecific TMs, thereby overcoming limitations of a monospecific treatment such as the selection of target-negative tumor escape variants. In order to advance our recently introduced prostate stem cell antigen (PSCA)-specific modular system for a dual-targeting of prostate cancer cells, two additional TMs were constructed: a monovalent/monospecific TM directed against the prostate-specific membrane antigen (PSMA) and a bivalent/bispecific TM (bsTM) with specificity for PSMA and PSCA. The functionality of the novel dual-targeting strategies was analyzed by performing T cell activation and chromium release assays. Similar to the PSCA-specific modular system, the novel PSMA-specific modular system mediates an efficient target-dependent and -specific tumor cell lysis at low E:T ratios and picomolar Ab concentrations. Moreover, by combination of the EM with either the bispecific TM directed to PSMA and PSCA or both monospecifc TMs directed to either PSCA or PSMA, dual-specific targeting complexes were formed which allowed us to kill potential escape variants expressing only one or the other target antigen. Overall, the novel modular system represents a promising tool for multiple tumor targeting. © 2014 Wiley Periodicals, Inc.

Circulating CXCR5+CD4+ T Follicular-Like Helper Cell and Memory B Cell Responses to Human Papillomavirus Vaccines

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Matsui, Ken; Adelsberger, Joseph W.; Kemp, Troy J.; Baseler, Michael W.; Ledgerwood, Julie E.; Pinto, Ligia A.

2015-01-01

Through the interaction of T follicular helper (Tfh) cells and B cells, efficacious vaccines can generate high-affinity, pathogen-neutralizing antibodies, and memory B cells. Using CXCR5, CXCR3, CCR6, CCR7, PD1, and ICOS as markers, Tfh-like cells can be identified in the circulation and be classified into three functionally distinct subsets that are PD1+ICOS+, PD1+ ICOS-, or PD1-ICOS-. We used these markers to identify different subsets of CXCR5+CD4+ Tfh-like cells in response to highly immunogenic and efficacious vaccines for human papillomaviruses (HPV): Cervarix and Gardasil. In this small study, we used PBMC samples from 11 Gardasil recipients, and 8 Cervarix recipients from the Vaccine Research Center 902 Study to examine the induction of circulating Tfh-like cells and IgD-CD38HiCD27+ memory B cells by flow cytometry. PD1+ICOS+ CXCR3+CCR6-CXCR5+CD4+ (Tfh1-like) cells were induced and peaked on Day (D) 7 post-first vaccination, but not as much on D7 post-third vaccination. We also observed a trend toward increase in PD1+ICOS+ CXCR3-CCR6-CXCR5+CD4+ (Tfh2-like) cells for both vaccines, and PD1+ICOS+ CXCR3-CCR6+CXCR5+CD4+ (Tfh17-like) subset was induced by Cervarix post-first vaccination. There were also minimal changes in the other cellular subsets. In addition, Cervarix recipients had more memory B cells post-first vaccination than did Gardasil recipients at D14 and D30. We found frequencies of memory B cells at D30 correlated with anti-HPV16 and 18 antibody titers from D30, and the induction levels of memory B cells at D30 and PD1+ICOS+Tfh1-like cells at D7 post-first vaccination correlated for Cervarix. Our study showed that induction of circulating CXCR5+CD4+ Tfh-like subsets can be detected following immunization with HPV vaccines, and potentially be useful as a marker of immunogenicity of vaccines. However, further investigations should be extended to different cohorts with larger sample size to better understand the functions of these T cells, as well as

Specificity and overlap of attention and memory biases in depression.

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Marchetti, Igor; Everaert, Jonas; Dainer-Best, Justin; Loeys, Tom; Beevers, Christopher G; Koster, Ernst H W

2018-01-01

Attentional and memory biases are viewed as crucial cognitive processes underlying symptoms of depression. However, it is still unclear whether these two biases are uniquely related to depression or whether they show substantial overlap. We investigated the degree of specificity and overlap of attentional and memory biases for depressotypic stimuli in relation to depression and anxiety by means of meta-analytic commonality analysis. By including four published studies, we considered a pool of 463 healthy and subclinically depressed individuals, different experimental paradigms, and different psychological measures. Memory bias is reliably and strongly related to depression and, specifically, to symptoms of negative mood, worthlessness, feelings of failure, and pessimism. Memory bias for negative information was minimally related to anxiety. Moreover, neither attentional bias nor the overlap between attentional and memory biases were significantly related to depression. Limitations include cross-sectional nature of the study. Our study showed that, across different paradigms and psychological measures, memory bias (and not attentional bias) represents a primary mechanism in depression. Copyright © 2017 Elsevier B.V. All rights reserved.

Frequency-specific insight into short-term memory capacity

OpenAIRE

Feurra, Matteo; Galli, Giulia; Pavone, Enea Francesco; Rossi, Alessandro; Rossi, Simone

2016-01-01

We provided novel evidence of a frequency-specific effect by transcranial alternating current stimulation (tACS) of the left posterior parietal cortex on short-term memory, during a digit span task. the effect was prominent with stimulation at beta frequency for young and not for middle-aged adults and correlated with age. Our findings highlighted a short-term memory capacity improvement by tACS application.

Effects of Task Instruction on Autobiographical Memory Specificity in Young and Older Adults

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Ford, Jaclyn Hennessey; Rubin, David C.; Giovanello, Kelly S.

2013-01-01

Older adults tend to retrieve autobiographical information that is overly general (i.e. not restricted to a single event, termed the overgenerality effect) relative to young adults’ specific memories. A vast majority of studies that have reported overgenerality effects explicitly instruct participants to retrieve specific memories, thereby requiring participants to maintain task goals, inhibit inappropriate responses, and control their memory search. Since these processes are impaired in healthy aging, it is important to determine whether such task instructions influence the magnitude of the overgenerality effect in older adults. In the current study, participants retrieved autobiographical memories during presentation of musical clips. Task instructions were manipulated to separate age-related differences in the specificity of underlying memory representations from age-related differences in following task instructions. Whereas young adults modulated memory specificity based on task demands, older adults did not. These findings suggest that reported rates of overgenerality in older adults’ memories may include age-related differences in memory representation, as well as differences in task compliance. Such findings provide a better understanding of the underlying cognitive mechanisms involved in age-related changes in autobiographical memory and may also be valuable for future research examining effects of overgeneral memory on general well-being. PMID:23915176

Effects of task instruction on autobiographical memory specificity in young and older adults.

Science.gov (United States)

Ford, Jaclyn Hennessey; Rubin, David C; Giovanello, Kelly S

2014-01-01

Older adults tend to retrieve autobiographical information that is overly general (i.e., not restricted to a single event, termed the overgenerality effect) relative to young adults' specific memories. A vast majority of studies that have reported overgenerality effects explicitly instruct participants to retrieve specific memories, thereby requiring participants to maintain task goals, inhibit inappropriate responses, and control their memory search. Since these processes are impaired in healthy ageing, it is important to determine whether such task instructions influence the magnitude of the overgenerality effect in older adults. In the current study participants retrieved autobiographical memories during presentation of musical clips. Task instructions were manipulated to separate age-related differences in the specificity of underlying memory representations from age-related differences in following task instructions. Whereas young adults modulated memory specificity based on task demands, older adults did not. These findings suggest that reported rates of overgenerality in older adults' memories might include age-related differences in memory representation, as well as differences in task compliance. Such findings provide a better understanding of the underlying cognitive mechanisms involved in age-related changes in autobiographical memory and may also be valuable for future research examining effects of overgeneral memory on general well-being.

Autobiographical memory specificity after manipulating retrieval cues in adults reporting childhood sexual abuse

NARCIS (Netherlands)

Hauer, Beatrijs J. A.; Wessel, Ineke; Geraerts, Elke; Merckelbach, Harald; Dalgleish, Tim

Traumatized samples have relative difficulty in generating specific autobiographical memories on a cue word task, compared to nonexposed controls. Simultaneously, trauma is associated with highly specific intrusive trauma memories in day-to-day life. Possibly, day-to-day intrusions and memories

Evaluation of twenty rapid antigen tests for the detection of human influenza A H5N1, H3N2, H1N1, and B viruses.

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Taylor, Janette; McPhie, Kenneth; Druce, Julian; Birch, Chris; Dwyer, Dominic E

2009-11-01

Twenty rapid antigen assays were compared for their ability to detect influenza using dilutions of virus culture supernatants from human isolates of influenza A H5N1 (clade 1 and 2 strains), H3N2 and H1N1 viruses, and influenza B. There was variation amongst the rapid antigen assays in their ability to detect different influenza viruses. Six of the 12 assays labeled as distinguishing between influenza A and B had comparable analytical sensitivities for detecting both influenza A H5N1 strains, although their ability to detect influenza A H3N2 and H1N1 strains varied. The two assays claiming H5 specificity did not detect either influenza A H5N1 strains, and the two avian influenza-specific assays detected influenza A H5N1, but missed some influenza A H3N2 virus supernatants. Clinical trials of rapid antigen tests for influenza A H5N1 are limited. For use in a pandemic where novel influenza strains are circulating (such as the current novel influenza A H1N1 09 virus), rapid antigen tests should ideally have comparable sensitivity and specificity for the new strains as for co-circulating seasonal influenza strains.

Characterization of antigen-specific, Ia-restricted, L3T4+ cytolytic T lymphocytes and assessment of thymic influence on their self specificity

International Nuclear Information System (INIS)

Golding, H.; Munitz, T.I.; Singer, A.

1985-01-01

The goals of the present study were: (a) to generate antigen-specific L3T4+ cytolytic T lymphocytes (CTL), (b) to determine their major histocompatibility complex (MHC) restriction specificity, and (c) to assess the influence of thymic MHC determinants on their self specificity. The authors found that L3T4+ CTL specific for either trinitrophenyl (TNP)-modified self determinants or minor histocompatibility antigens could be generated from Lyt-2- responder T cells provided that the response cultures were supplemented with supernatants rich in helper factors. Such antigen-specific L3T4+ CTL were Ia-restricted by the criteria that they lysed only Ia+ target cells and that their lysis of Ia+ target cells was specifically inhibited by anti-Ia monoclonal antibodies. The relative frequency of L3T4+ pCTL was found to be only 5-10% of the total anti-TNP pCTL present in the spleens of normal mice. Finally, the authors utilized radiation bone marrow chimeras to assess the influence of the thymic haplotype on the self-Ia specificity of L3T4+ CTL. Both bulk culture and limiting dilution experiments revealed that the self-Ia specificity of L3T4+ anti-TNP CTL from F1----parent and A----B allogeneic chimeras was not markedly skewed toward the haplotype of the chimeric thymus. These results contrast with those obtained previously for L3T4+ anti-TNP Th cells and demonstrate that in the radiation bone marrow chimera model of T cell differentiation, the self specificity of Th cells but not pCTL is markedly influenced by the haplotype of the chimeric thymus

Profiling Humoral Immune Responses to Clostridium difficile-Specific Antigens by Protein Microarray Analysis.

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Negm, Ola H; Hamed, Mohamed R; Dilnot, Elizabeth M; Shone, Clifford C; Marszalowska, Izabela; Lynch, Mark; Loscher, Christine E; Edwards, Laura J; Tighe, Patrick J; Wilcox, Mark H; Monaghan, Tanya M

2015-09-01

Clostridium difficile is an anaerobic, Gram-positive, and spore-forming bacterium that is the leading worldwide infective cause of hospital-acquired and antibiotic-associated diarrhea. Several studies have reported associations between humoral immunity and the clinical course of C. difficile infection (CDI). Host humoral immune responses are determined using conventional enzyme-linked immunosorbent assay (ELISA) techniques. Herein, we report the first use of a novel protein microarray assay to determine systemic IgG antibody responses against a panel of highly purified C. difficile-specific antigens, including native toxins A and B (TcdA and TcdB, respectively), recombinant fragments of toxins A and B (TxA4 and TxB4, respectively), ribotype-specific surface layer proteins (SLPs; 001, 002, 027), and control proteins (tetanus toxoid and Candida albicans). Microarrays were probed with sera from a total of 327 individuals with CDI, cystic fibrosis without diarrhea, and healthy controls. For all antigens, precision profiles demonstrated ELISA in the quantification of antitoxin A and antitoxin B IgG. These results indicate that microarray is a suitable assay for defining humoral immune responses to C. difficile protein antigens and may have potential advantages in throughput, convenience, and cost. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

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.

The association of heavy and light chain variable domains in antibodies: implications for antigen specificity.

KAUST Repository

Chailyan, Anna

2011-06-28

The antigen-binding site of immunoglobulins is formed by six regions, three from the light and three from the heavy chain variable domains, which, on association of the two chains, form the conventional antigen-binding site of the antibody. The mode of interaction between the heavy and light chain variable domains affects the relative position of the antigen-binding loops and therefore has an effect on the overall conformation of the binding site. In this article, we analyze the structure of the interface between the heavy and light chain variable domains and show that there are essentially two different modes for their interaction that can be identified by the presence of key amino acids in specific positions of the antibody sequences. We also show that the different packing modes are related to the type of recognized antigen.

Anvendelse af prostataspecifikt antigen. En oversigt

DEFF Research Database (Denmark)

Brasso, K; Skaarup, P; Roosen, Jens Ulrik

1998-01-01

Since it was first introduced, measurement of prostate specific antigen has gained increasing interest, and prostate specific antigen is regarded as being the best tumour marker available. The antigen lacks cancer specificity, limiting the usefulness in early diagnosis, The use of prostate specific...... antigen in early diagnosis, staging, and in monitoring patients with prostate cancer is reviewed....

Epstein-Barr virus nuclear antigen 2 specifically induces expression of the B-cell activation antigen CD23

International Nuclear Information System (INIS)

Wang, F.; Gregory, C.D.; Rowe, M.; Rickinson, A.B.; Wang, D.; Birkenbach, M.; Kikutani, H.; Kishimoto, T.; Kieff, E.

1987-01-01

Epstein-Barr virus (EBV) infection of EBV-negative Burkitt lymphoma (BL) cells includes some changes similar to those seen in normal B lymphocytes that have been growth transformed by EBV. The role of individual EBV genes in this process was evaluated by introducing each of the viral genes that are normally expressed in EBV growth-transformed and latently infected lymphoblasts into an EBV-negative BL cell line, using recombinant retrovirus-mediated transfer. Clones of cells were derived that stably express the EBV nuclear antigen 1 (EBNA-1), EBNA-2, EBNA-3, EBNA-leader protein, or EBV latent membrane protein (LMP). These were compared with control clones infected with the retrovirus vector. All 10 clones converted to EBNA-2 expression differed from control clones or clones expressing other EBV proteins by growth in tight clumps and by markedly increased expression of one particular surface marker of B-cell activation, CD23. Other activation antigens were unaffected by EBNA-2 expression, as were markers already expressed on the parent BL cell line. The results indicate that EBNA-2 is a specific direct or indirect trans-activator of CD23. This establishes a link between an EBV gene and cell gene expression. Since CD23 has been implicated in the transduction of B-cell growth signals, its specific induction by EBNA-2 could be important in EBV induction of B-lymphocyte transformation

Isolation and characterization of antigen-specific alpaca (Lama pacos) VHH antibodies by biopanning followed by high-throughput sequencing.

Science.gov (United States)

Miyazaki, Nobuo; Kiyose, Norihiko; Akazawa, Yoko; Takashima, Mizuki; Hagihara, Yosihisa; Inoue, Naokazu; Matsuda, Tomonari; Ogawa, Ryu; Inoue, Seiya; Ito, Yuji

2015-09-01

The antigen-binding domain of camelid dimeric heavy chain antibodies, known as VHH or Nanobody, has much potential in pharmaceutical and industrial applications. To establish the isolation process of antigen-specific VHH, a VHH phage library was constructed with a diversity of 8.4 × 10(7) from cDNA of peripheral blood mononuclear cells of an alpaca (Lama pacos) immunized with a fragment of IZUMO1 (IZUMO1PFF) as a model antigen. By conventional biopanning, 13 antigen-specific VHHs were isolated. The amino acid sequences of these VHHs, designated as N-group VHHs, were very similar to each other (>93% identity). To find more diverse antibodies, we performed high-throughput sequencing (HTS) of VHH genes. By comparing the frequencies of each sequence between before and after biopanning, we found the sequences whose frequencies were increased by biopanning. The top 100 sequences of them were supplied for phylogenic tree analysis. In total 75% of them belonged to N-group VHHs, but the other were phylogenically apart from N-group VHHs (Non N-group). Two of three VHHs selected from non N-group VHHs showed sufficient antigen binding ability. These results suggested that biopanning followed by HTS provided a useful method for finding minor and diverse antigen-specific clones that could not be identified by conventional biopanning. © The Authors 2015. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved.

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

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...... 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...

Working, declarative and procedural memory in specific language impairment

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Lum, Jarrad A.G.; Conti-Ramsden, Gina; Page, Debra; Ullman, Michael T.

2012-01-01

According to the Procedural Deficit Hypothesis (PDH), abnormalities of brain structures underlying procedural memory largely explain the language deficits in children with specific language impairment (SLI). These abnormalities are posited to result in core deficits of procedural memory, which in turn explain the grammar problems in the disorder. The abnormalities are also likely to lead to problems with other, non-procedural functions, such as working memory, that rely at least partly on the affected brain structures. In contrast, declarative memory is expected to remain largely intact, and should play an important compensatory role for grammar. These claims were tested by examining measures of working, declarative and procedural memory in 51 children with SLI and 51 matched typically-developing (TD) children (mean age 10). Working memory was assessed with the Working Memory Test Battery for Children, declarative memory with the Children’s Memory Scale, and procedural memory with a visuo-spatial Serial Reaction Time task. As compared to the TD children, the children with SLI were impaired at procedural memory, even when holding working memory constant. In contrast, they were spared at declarative memory for visual information, and at declarative memory in the verbal domain after controlling for working memory and language. Visuo-spatial short-term memory was intact, whereas verbal working memory was impaired, even when language deficits were held constant. Correlation analyses showed neither visuo-spatial nor verbal working memory was associated with either lexical or grammatical abilities in either the SLI or TD children. Declarative memory correlated with lexical abilities in both groups of children. Finally, grammatical abilities were associated with procedural memory in the TD children, but with declarative memory in the children with SLI. These findings replicate and extend previous studies of working, declarative and procedural memory in SLI. Overall, we

Circulating Prostate-Specific Antigen and Telomere Length in a Nationally Representative Sample of Men Without History of Prostate Cancer.

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Wulaningsih, Wahyu; Astuti, Yuliana; Matsuguchi, Tetsuya; Anggrandariyanny, Putri; Watkins, Johnathan

2017-01-01

We investigated the association of prostate-specific antigen (PSA) with leukocyte telomere length, which may be altered in preclinical prostate malignancies. This study was based on the 2001-2002 U.S. National Health and Nutrition Examination Survey (NHANES). A subsample of 1,127 men aged 40-85 years without prior history of prostate cancer who provided informed consent and blood samples were selected. Leukocyte telomere length (LTL) relative to standard DNA reference (T/S ratio) was quantified by polymerase chain reaction (PCR). Survey-weighted multivariable linear regression was performed to examine T/S ratio across quintiles of total and free PSA and free-to-total PSA ratio (%fPSA). A sensitivity analysis was performed by excluding men dying from prostate cancer during follow-up through to December 31, 2006. Stratification analyses were carried out to assess any effect modification by age group, race, body mass index (BMI), and levels of C-reactive protein (CRP), a marker of inflammation. Higher total PSA levels were associated to longer LTL, with approximately 8% increase in log-transformed T/S ratio (95% confidence interval [CI]: 2-13%) among men in the highest quintile of total PSA compared to the lowest in the fully adjusted model (P trend  = 0.01). No significant association was found for free PSA or %fPSA, although nonlinearity between all PSA measures and T/S ratio was indicated. Similar results were found after excluding men who died from prostate cancer during follow-up. We also found the associations between total PSA and T/S ratio to be strongest among non-Hispanic blacks, non-obese men (BMI specific mechanisms contributing to prostate cancer development. Prostate 77:22-32, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Mother-Child Reminiscing and Autobiographical Memory Specificity among Preschool-Age Children

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Valentino, Kristin; Nuttall, Amy K.; Comas, Michelle; McDonnell, Christina G.; Piper, Brianna; Thomas, Taylor E.; Fanuele, Suzanne

2014-01-01

Overgeneral memory (OGM) refers to difficulty in retrieving specific autobiographical memories. The tendency to be overgeneral in autobiographical memory recall is more commonly observed among individuals with emotional disorders compared with those without. Despite significant advances in theory and identification of mechanisms that underlie the…

Mucosal immunization in macaques upregulates the innate APOBEC 3G anti-viral factor in CD4(+) memory T cells.

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Wang, Yufei; Bergmeier, Lesley A; Stebbings, Richard; Seidl, Thomas; Whittall, Trevor; Singh, Mahavir; Berry, Neil; Almond, Neil; Lehner, Thomas

2009-02-05

APOBEC3G is an innate intracellular anti-viral factor which deaminates retroviral cytidine to uridine. In vivo studies of APOBEC3G (A3G) were carried out in rhesus macaques, following mucosal immunization with SIV antigens and CCR5 peptides, linked to the 70kDa heat shock protein. A progressive increase in A3G mRNA was elicited in PBMC after each immunization (p<0.0002 to p< or =0.02), which was maintained for at least 17 weeks. Analysis of memory T cells showed a significant increase in A3G mRNA and protein in CD4(+)CCR5(+) memory T cells in circulating (p=0.0001), splenic (p=0.0001), iliac lymph nodes (p=0.002) and rectal (p=0.01) cells of the immunized compared with unimmunized macaques. Mucosal challenge with SIVmac 251 showed a significant increase in A3G mRNA in the CD4(+)CCR5(+) circulating cells (p<0.01) and the draining iliac lymph node cells (p<0.05) in the immunized uninfected macaques, consistent with a protective effect exerted by A3G. The results suggest that mucosal immunization in a non-human primate can induce features of a memory response to an innate anti-viral factor in CCR5(+)CD4(+) memory and CD4(+)CD95(+)CCR7(-) effector memory T cells.

Phonological working memory and auditory processing speed in children with specific language impairment

Directory of Open Access Journals (Sweden)

Fatemeh Haresabadi

2015-02-01

Full Text Available Background and Aim: Specific language impairment (SLI, one variety of developmental language disorder, has attracted much interest in recent decades. Much research has been conducted to discover why some children have a specific language impairment. So far, research has failed to identify a reason for this linguistic deficiency. Some researchers believe language disorder causes defects in phonological working memory and affects auditory processing speed. Therefore, this study reviews the results of research investigating these two factors in children with specific language impairment.Recent Findings: Studies have shown that children with specific language impairment face constraints in phonological working memory capacity. Memory deficit is one possible cause of linguistic disorder in children with specific language impairment. However, in these children, disorder in information processing speed is observed, especially regarding the auditory aspect.Conclusion: Much more research is required to adequately explain the relationship between phonological working memory and auditory processing speed with language. However, given the role of phonological working memory and auditory processing speed in language acquisition, a focus should be placed on phonological working memory capacity and auditory processing speed in the assessment and treatment of children with a specific language impairment.

Spatial specificity of working memory representations in the early visual cortex.

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Pratte, Michael S; Tong, Frank

2014-03-19

Recent fMRI decoding studies have demonstrated that early retinotopic visual areas exhibit similar patterns of activity during the perception of a stimulus and during the maintenance of that stimulus in working memory. These findings provide support for the sensory recruitment hypothesis that the mechanisms underlying perception serve as a foundation for visual working memory. However, a recent study by Ester, Serences, and Awh (2009) found that the orientation of a peripheral grating maintained in working memory could be classified from both the contralateral and ipsilateral regions of the primary visual cortex (V1), implying that, unlike perception, feature-specific information was maintained in a nonretinotopic manner. Here, we evaluated the hypothesis that early visual areas can maintain information in a spatially specific manner and will do so if the task encourages the binding of feature information to a specific location. To encourage reliance on spatially specific memory, our experiment required observers to retain the orientations of two laterally presented gratings. Multivariate pattern analysis revealed that the orientation of each remembered grating was classified more accurately based on activity patterns in the contralateral than in the ipsilateral regions of V1 and V2. In contrast, higher extrastriate areas exhibited similar levels of performance across the two hemispheres. A time-resolved analysis further indicated that the retinotopic specificity of the working memory representation in V1 and V2 was maintained throughout the retention interval. Our results suggest that early visual areas provide a cortical basis for actively maintaining information about the features and locations of stimuli in visual working memory.

Antigen-Specific Th17 Cells Are Primed by Distinct and Complementary Dendritic Cell Subsets in Oropharyngeal Candidiasis.

Directory of Open Access Journals (Sweden)

Kerstin Trautwein-Weidner

2015-10-01

Full Text Available Candida spp. can cause severe and chronic mucocutaneous and systemic infections in immunocompromised individuals. Protection from mucocutaneous candidiasis depends on T helper cells, in particular those secreting IL-17. The events regulating T cell activation and differentiation toward effector fates in response to fungal invasion in different tissues are poorly understood. Here we generated a Candida-specific TCR transgenic mouse reactive to a novel endogenous antigen that is conserved in multiple distant species of Candida, including the clinically highly relevant C. albicans and C. glabrata. Using TCR transgenic T cells in combination with an experimental model of oropharyngeal candidiasis (OPC we investigated antigen presentation and Th17 priming by different subsets of dendritic cells (DCs present in the infected oral mucosa. Candida-derived endogenous antigen accesses the draining lymph nodes and is directly presented by migratory DCs. Tissue-resident Flt3L-dependent DCs and CCR2-dependent monocyte-derived DCs collaborate in antigen presentation and T cell priming during OPC. In contrast, Langerhans cells, which are also present in the oral mucosa and have been shown to prime Th17 cells in the skin, are not required for induction of the Candida-specific T cell response upon oral challenge. This highlights the functional compartmentalization of specific DC subsets in different tissues. These data provide important new insights to our understanding of tissue-specific antifungal immunity.

Placental restriction of fetal growth reduces cutaneous responses to antigen after sensitization in sheep.

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Wooldridge, Amy L; Bischof, Robert J; Meeusen, Els N; Liu, Hong; Heinemann, Gary K; Hunter, Damien S; Giles, Lynne C; Kind, Karen L; Owens, Julie A; Clifton, Vicki L; Gatford, Kathryn L

2014-04-01

Prenatal and early childhood exposures are implicated as causes of allergy, but the effects of intrauterine growth restriction on immune function and allergy are poorly defined. We therefore evaluated effects of experimental restriction of fetal growth on immune function and allergic sensitization in adolescent sheep. Immune function (circulating total red and white blood cells, neutrophils, lymphocytes, monocytes, eosinophils, and basophils, and the antibody response to Clostridial vaccination) and responses to house dust mite (HDM) allergen and ovalbumin (OVA) antigen sensitization (specific total Ig, IgG1, and IgE antibodies, and cutaneous hypersensitivity) were investigated in adolescent sheep from placentally restricted (PR, n = 23) and control (n = 40) pregnancies. Increases in circulating HDM-specific IgE (P = 0.007) and OVA-specific IgE (P = 0.038) were greater in PR than control progeny. PR did not alter total Ig, IgG1, or IgM responses to either antigen. PR increased OVA-specific but not HDM-specific IgA responses in females only (P = 0.023). Multiple birth increased Ig responses to OVA in a sex-specific manner. PR decreased the proportion of positive cutaneous hypersensitivity responders to OVA at 24 h (P = 0.030) but had no effect on cutaneous responses to HDM. Acute wheal responses to intradermal histamine correlated positively with birth weight in singletons (P = 0.023). Intrauterine growth restriction may suppress inflammatory responses in skin downstream of IgE induction, without impairment in antibody responses to a nonpolysaccharide vaccine. Discord between cutaneous and IgE responses following sensitization suggests new mechanisms for prenatal allergy programming.

Regulatory role for the memory B cell as suppressor-inducer of feedback control

International Nuclear Information System (INIS)

Kennedy, M.W.; Thomas, D.B.

1983-01-01

A regulatory role is proposed for the antigen-responsive B cell, as suppressor-inducer of feedback control during the secondary response in vivo. In a double adoptive transfer of memory cells primed to a thymus-dependent antigen from one irradiated host to another, antigen-specific suppressors are generated after a critical time in the primary recipient, able to entirely ablate a secondary anti-hapten response. Positive cell selection in the fluorescence-activated cell sorter confirmed that suppression was mediated by an Lyt-2+ T cell; however, positively selected B cells were also inhibitory and able to induce suppressors in a carrier-specific manner: B hapten induced suppressors in a carrier-primed population, and B carrier induced suppressors in a hapten-carrier population. At the peak of the antibody response in the primary host, memory B cells and their progeny were unable to differentiate further to plasma cells due to their intrinsic suppressor-inducer activity, but this autoregulatory circuit could be severed by adoptive transfer to carrier-primed, X-irradiated recipients

[Prostate specific antigen and NF-kB in prostatic disease: relation with malignancy].

Science.gov (United States)

Cansino, J R; Vera, R; Rodríguez de Bethencourt, F; Bouraoui, Y; Rodríguez, G; Prieto, A; de la Peña, J; Paniagua, R; Royuela, M

2011-01-01

NF-kB (p50/p65) is a transcription factor involved in TNF-α-induced cell death resistance by promoting several antiapoptotic genes. We intend to relate the expression of NF-kB (p50 and p65) with serum levels of prostate-specific antigen (PSA), both in normal males and in those with pathologic conditions of the prostate. this study was carried out in 5 normal, 24 benign prostatic hyperplastic (BPH) and 19 patients with prostate cancer (PC). Immunohistochemical and Western blot analyses were performed on tissue and serum PSA was assayed by PSA DPC Immulite assays (Diagnostics Products Corporation, Los Angeles, CA). in controls, p65 NF-kB was not found and p50 was scantly detected in 60% normal samples in the cytoplasm of epithelial cells. Both p50 and p65 were expressed in 62.5% of the samples with BPH and in 63.2% of those with PC. Both increased its frequency of expression with higher PSA serum levels. Activation of NF-kB revealed by its nuclear translocation in prostate cancer could be related to cancer progression and elevated seric PSA levels. A better understanding of the biologic mechanism by which circulating PSA levels increase and its relation with NF-kB expression is needed. Possibly, NF-kB blockage could be used as a therapeutic target to counteract proliferation in prostate cancer. Copyright © 2010 AEU. Published by Elsevier Espana. All rights reserved.

Dynamic imaging of experimental Leishmania donovani-induced hepatic granulomas detects Kupffer cell-restricted antigen presentation to antigen-specific CD8 T cells.

Directory of Open Access Journals (Sweden)

Lynette Beattie

2010-03-01

Full Text Available Kupffer cells (KCs represent the major phagocytic population within the liver and provide an intracellular niche for the survival of a number of important human pathogens. Although KCs have been extensively studied in vitro, little is known of their in vivo response to infection and their capacity to directly interact with antigen-specific CD8(+ T cells. Here, using a combination of approaches including whole mount and thin section confocal microscopy, adoptive cell transfer and intra-vital 2-photon microscopy, we demonstrate that KCs represent the only detectable population of mononuclear phagocytes within granulomas induced by Leishmania donovani infection that are capable of presenting parasite-derived peptide to effector CD8(+ T cells. This restriction of antigen presentation to KCs within the Leishmania granuloma has important implications for the identification of new candidate vaccine antigens and for the design of novel immuno-therapeutic interventions.

Prostate-specific antigen testing accuracy in community practice

Directory of Open Access Journals (Sweden)

Adams-Cameron Meg

2002-10-01

Full Text Available Abstract Background Most data on prostate-specific antigen (PSA testing come from urologic cohorts comprised of volunteers for screening programs. We evaluated the diagnostic accuracy of PSA testing for detecting prostate cancer in community practice. Methods PSA testing results were compared with a reference standard of prostate biopsy. Subjects were 2,620 men 40 years and older undergoing (PSA testing and biopsy from 1/1/95 through 12/31/98 in the Albuquerque, New Mexico metropolitan area. Diagnostic measures included the area under the receiver-operating characteristic curve, sensitivity, specificity, and likelihood ratios. Results Cancer was detected in 930 subjects (35%. The area under the ROC curve was 0.67 and the PSA cutpoint of 4 ng/ml had a sensitivity of 86% and a specificity of 33%. The likelihood ratio for a positive test (LR+ was 1.28 and 0.42 for a negative test (LR-. PSA testing was most sensitive (90% but least specific (27% in older men. Age-specific reference ranges improved specificity in older men (49% but decreased sensitivity (70%, with an LR+ of 1.38. Lowering the PSA cutpoint to 2 ng/ml resulted in a sensitivity of 95%, a specificity of 20%, and an LR+ of 1.19. Conclusions PSA testing had fair discriminating power for detecting prostate cancer in community practice. The PSA cutpoint of 4 ng/ml was sensitive but relatively non-specific and associated likelihood ratios only moderately revised probabilities for cancer. Using age-specific reference ranges and a PSA cutpoint below 4 ng/ml improved test specificity and sensitivity, respectively, but did not improve the overall accuracy of PSA testing.

Differential Patterns of Large Tumor Antigen-Specific Immune Responsiveness in Patients with BK Polyomavirus-Positive Prostate Cancer or Benign Prostatic Hyperplasia

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Sais, Giovanni; Wyler, Stephen; Hudolin, Tvrtko; Banzola, Irina; Mengus, Chantal; Bubendorf, Lukas; Wild, Peter J.; Hirsch, Hans H.; Sulser, Tullio; Spagnoli, Giulio C.

2012-01-01

The role of the polyomavirus BK (BKV) large tumor antigen (L-Tag) as a target of immune response in patients with prostate cancer (PCa) has not been investigated thus far. In this study, we comparatively analyzed humoral and cellular L-Tag-specific responsiveness in age-matched patients bearing PCa or benign prostatic hyperplasia, expressing or not expressing BKV L-Tag-specific sequences in their tissue specimens, and in non-age-matched healthy individuals. Furthermore, results from patients with PCa were correlated to 5-year follow-up clinical data focusing on evidence of biochemical recurrence (BR) after surgery (prostate specific antigen level of ≥0.2 ng/ml). In peripheral blood mononuclear cells (PBMC) from patients with PCa with evidence of BR and BKV L-Tag-positive tumors, stimulation with peptides derived from the BKV L-Tag but not those derived from Epstein-Barr virus, influenza virus, or cytomegalovirus induced a peculiar cytokine gene expression profile, characterized by high expression of interleukin-10 (IL-10) and transforming growth factor β1 and low expression of gamma interferon genes. This pattern was confirmed by protein secretion data and correlated with high levels of anti-BKV L-Tag IgG. Furthermore, in PBMC from these PCa-bearing patients, L-Tag-derived peptides significantly expanded an IL-10-secreting CD4+ CD25+(high) CD127− FoxP3+ T cell population with an effector memory phenotype (CD103+) capable of inhibiting proliferation of autologous anti-CD3/CD28-triggered CD4+ CD25− T cells. Collectively, our findings indicate that potentially tolerogenic features of L-Tag-specific immune response are significantly associated with tumor progression in patients with BKV+ PCa. PMID:22647697

Comparative evaluation of the diagnostic potential of recombinant envelope proteins and native cell culture purified viral antigens of Chikungunya virus.

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Khan, Mohsin; Dhanwani, Rekha; Kumar, Jyoti S; Rao, P V Lakshmana; Parida, Manmohan

2014-07-01

Despite the fact that Chikungunya resurgence is associated with epidemic of unprecedented magnitude, there are challenges in the field of its clinical diagnosis. However, serological tests in an ELISA format provide a rapid tool for the diagnosis of Chikungunya infection. Indeed, ELISAs based on recombinant proteins hold a great promise as these methods are cost effective and are free from the risk of handling biohazardous material. In this study, the performance of recombinant CHIKV antigens was compared in various ELISA formats for the diagnosis of Chikungunya. Two recombinant antigens derived from the envelope proteins of Chikungunya virus were prepared and evaluated by comparing their competence for detecting circulating antibodies in serum samples of patients infected with CHIKV using MAC-ELISA and indirect IgM-ELISA. The efficacy of the recombinant antigens was also compared with the native antigen. The indirect antibody capture IgM microplate ELISA revealed ≥90% concordance with the native antigen in detecting the CHIKV specific IgM antibodies whereas the recombinant antigen based MAC-ELISA showed 100% specificity. The recombinant antigens used in this study were effective and reliable targets for the diagnosis of CHIKV infection and also provide an alternative for native antigen use which is potentially biohazardous. © 2013 Wiley Periodicals, Inc.

The effect of increasing doses of saw palmetto fruit extract on serum prostate specific antigen: analysis of the CAMUS randomized trial.

Science.gov (United States)

Andriole, Gerald L; McCullum-Hill, Christie; Sandhu, Gurdarshan S; Crawford, E David; Barry, Michael J; Cantor, Alan

2013-02-01

Saw palmetto extracts are used to treat lower urinary tract symptoms in men despite level I evidence that saw palmetto is ineffective in reducing these lower urinary tract symptoms. We determined whether higher doses of saw palmetto as studied in the CAMUS (Complementary and Alternative Medicine for Urologic Symptoms) trial affect serum prostate specific antigen levels. The CAMUS trial was a randomized, placebo controlled, double-blind, multicenter, North American trial conducted between June 5, 2008 and October 10, 2012, in which 369 men older than 45 years with an AUA symptom score of 8 to 24 were randomly assigned to placebo or dose escalation of saw palmetto, which consisted of 320 mg for the first 24 weeks, 640 mg for the next 24 weeks and 960 mg for the last 24 weeks of this 72-week trial. Serum prostate specific antigen levels were obtained at baseline and at weeks 24, 48 and 72, and were compared between treatment groups using the pooled t test and Fisher's exact test. Serum prostate specific antigen was similar at baseline for the placebo (mean ± SD 1.93 ± 1.59 ng/ml) and saw palmetto groups (2.20 ± 1.95, p = 0.16). Changes in prostate specific antigen during the study were similar, with a mean change in the placebo group of 0.16 ± 1.08 ng/ml and 0.23 ± 0.83 ng/ml in the saw palmetto group (p = 0.50). In addition, no differential effect on serum prostate specific antigen was observed between treatment arms when the groups were stratified by baseline prostate specific antigen. Saw palmetto extract does not affect serum prostate specific antigen more than placebo, even at relatively high doses. Copyright © 2013 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

The simultaneous ex vivo detection of low-frequency antigen-specific CD4+ and CD8+ T-cell responses using overlapping peptide pools.

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Singh, Satwinder Kaur; Meyering, Maaike; Ramwadhdoebe, Tamara H; Stynenbosch, Linda F M; Redeker, Anke; Kuppen, Peter J K; Melief, Cornelis J M; Welters, Marij J P; van der Burg, Sjoerd H

2012-11-01

The ability to measure antigen-specific T cells at the single-cell level by intracellular cytokine staining (ICS) is a promising immunomonitoring tool and is extensively applied in the evaluation of immunotherapy of cancer. The protocols used to detect antigen-specific CD8+ T-cell responses generally work for the detection of antigen-specific T cells in samples that have undergone at least one round of in vitro pre-stimulation. Application of a common protocol but now using long peptides as antigens was not suitable to simultaneously detect antigen-specific CD8+ and CD4+ T cells directly ex vivo in cryopreserved samples. CD8 T-cell reactivity to monocytes pulsed with long peptides as antigens ranged between 5 and 25 % of that observed against monocytes pulsed with a direct HLA class I fitting minimal CTL peptide epitope. Therefore, we adapted our ICS protocol and show that the use of tenfold higher concentration of long peptides to load APC, the use of IFN-α and poly(I:C) to promote antigen processing and improve T-cell stimulation, does allow for the ex vivo detection of low-frequency antigen-specific CD8+ and CD4+ T cells in an HLA-independent setting. While most of the improvements were related to increasing the ability to measure CD8+ T-cell reactivity following stimulation with long peptides to at least 50 % of the response detected when using a minimal peptide epitope, the final analysis of blood samples from vaccinated patients successfully showed that the adapted ICS protocol also increases the ability to ex vivo detect low-frequency p53-specific CD4+ T-cell responses in cryopreserved PBMC samples.

Validation of a urine circulating cathodic antigen cassette test for detection of Schistosoma haematobiumin uMkhanyakude district of South Africa.

Science.gov (United States)

Rubaba, O; Chimbari, M J; Soko, W; Manyangadze, T; Mukaratirwa, S

2018-06-01

Circulating cathodic antigen (CCA) tests for schistosomiasis are fast and less complicated allowing making them good candidates for routine qualitative screening for schistosomiasis at point of care. The urine-CCA has been evaluated for detection of S. mansoni with promising results. Its specificity and consistency in detecting S. haematobium infection in different endemic regions has been variable. This study validated a rapid urine-CCA cassette test for qualitative detection of S. haematobium infection in an S. haematobium endemic area with low S. mansoni prevalence. Microscopic examination for the standard urine filtration technique was used to validate the commercially available urine-CCA cassette test (rapid medical diagnostics ® ). The validation was done in a sample of primary school pupils (n = 420) aged 10-15 years in schools in the Jozini Municipality, KZN. There was a relationship between infection intensity and a positive urine-CCA test. Using the urine filtration method as the gold standard, the prevalence for S. haematobium was 40%, the accuracy of the CCA kit was 54.8%, sensitivity was 68.1% while the specificity was 45.8%. The positive predictive value was 45.82% while the negative predictive value was 68.05%. Both the urine filtration and the urine-CCA methods detected heavy (≥50 eggs/10 mL urine) and light infections at statistically significant levels. The overall accuracy, sensitivity and specificity of the urine-CCA cassette test were low. The urine-CCA cassette test performed much better for heavy infections than low infections (p < 0.05) implying that the kit may not be suitable for low endemic areas. Copyright © 2018 Elsevier B.V. All rights reserved.

[Production, specificity and structure of immunoglobulins].

Science.gov (United States)

Goujard, C; Delfraissy, J F

1991-03-21

Immunoglobulin is a key factor of the immune response resulting from B-cell activation and associated with T-cell stimulation. Because of its structure, this antibody has a dual function: it specifically recognizes the inducer antigen in the variable region and eliminates it by a constant portion which is responsible for effector properties. Surface immunoglobulin, therefore, is the B-cell antigen receptor; it differs from the T-cell receptor in that it recognizes the antigen unbound to the major istocompatibility complex; binding the antigen results in direct signal transduction first in the cytoplasm, then in the nucleus. This receptor can be secreted in the body: it is made up of circulating immunoglobulins. Human immunoglobulins are divided into 5 classes, each of them with its own response kinetics, distribution and functions. The variability of the antibody response accounts for a genetic organization involving numerous genes which may be associated with each other, or mutate, or recombine during maturation of the lymphocytes. Altogether, this system has a theoretical capacity of response to three hundred million different antigens.

Prepartum autobiographical memory specificity predicts post-traumatic stress symptoms following complicated pregnancy

NARCIS (Netherlands)

Hauer, Beatrijs J. A.; Wessel, Ineke; Engelhard, Iris M.; Peeters, Louis L.; Dalgleish, Tim

2009-01-01

Prior research has shown that reduced autobiographical memory specificity predicts an increase in post-traumatic stress severity in traumatised individuals. Studies have also demonstrated that reduced memory specificity predicts later symptoms of depression after pregnancy-related life stress. So

Refining the LPS-Antigen in Salmonella Antibody Elisa for Poultry Enhanced Specificity without Impairing Sensitivity

DEFF Research Database (Denmark)

Lauritsen, Klara Tølbøl; Lind, Peter; Klausen, Joan

2014-01-01

In the Danish serological surveillance for Salmonella in poultry (serum and egg yolk) a mix-ELISA is used, based on S. typhimurium and S. enteritidis antigens (Feld et al., 2000). When we evaluated results of the test retrospectively, over the years an unacceptably large fraction of seropositive...... findings could not be confirmed by the subsequent confirmatory bacteriological sampling in the herd. Therefore we tried to enhance specificity of the ELISA, without losing sensitivity, by refining the antigens used....

Biological variation of total prostate-specific antigen

DEFF Research Database (Denmark)

Söletormos, Georg; Semjonow, Axel; Sibley, Paul E C

2005-01-01

BACKGROUND: The objectives of this study were to determine whether a single result for total prostate-specific antigen (tPSA) can be used confidently to guide the need for prostate biopsy and by how much serial tPSA measurements must differ to be significant. tPSA measurements include both...... analytical and biological components of variation. The European Group on Tumor Markers conducted a literature survey to determine both the magnitude and impact of biological variation on single, the mean of replicate, and serial tPSA measurements. METHODS: The survey yielded 27 studies addressing the topic......, and estimates for the biological variation of tPSA could be derived from 12 of these studies. RESULTS: The mean biological variation was 20% in the concentration range 0.1-20 microg/L for men over 50 years. The biological variation means that the one-sided 95% confidence interval (CI) of the dispersion...

Specific Nongluten Proteins of Wheat Are Novel Target Antigens in Celiac Disease Humoral Response

Science.gov (United States)

2014-01-01

While the antigenic specificity and pathogenic relevance of immunologic reactivity to gluten in celiac disease have been extensively researched, the immune response to nongluten proteins of wheat has not been characterized. We aimed to investigate the level and molecular specificity of antibody response to wheat nongluten proteins in celiac disease. Serum samples from patients and controls were screened for IgG and IgA antibody reactivity to a nongluten protein extract from the wheat cultivar Triticum aestivum Butte 86. Antibodies were further analyzed for reactivity to specific nongluten proteins by two-dimensional gel electrophoresis and immunoblotting. Immunoreactive molecules were identified by tandem mass spectrometry. Compared with healthy controls, patients exhibited significantly higher levels of antibody reactivity to nongluten proteins. The main immunoreactive nongluten antibody target proteins were identified as serpins, purinins, α-amylase/protease inhibitors, globulins, and farinins. Assessment of reactivity toward purified recombinant proteins further confirmed the presence of antibody response to specific antigens. The results demonstrate that, in addition to the well-recognized immune reaction to gluten, celiac disease is associated with a robust humoral response directed at a specific subset of the nongluten proteins of wheat. PMID:25329597

[Detection of fps tumor antigen with mono-specific anti-fps serum in tumors induced by acute transforming ALV].

Science.gov (United States)

Wang, Yixin; Chen, Hao; Zhao, Peng; Li, Jianliang; Cui, Zhizhong

2013-03-04

To prepare anti-fps mono-specific serum, and detect the fps antigen in tumors induced by acute transforming avian leukosis/sarcoma virus containing v-fps oncogene. Two part of v-fps gene was amplified by RT-PCR using the Fu-J viral RNA as the template. Mono-specific serum was prepared by immuning Kunming white mouse with both two recombinant infusion proteins expressed by the prokaryotic expression system. Indirect immunofluorescent assay was used to detect fps antigen in tumor tissue suspension cells and CEF infected by sarcoma supernatant. Immunohistochemical method was used to detect fps antigen in tumor tissue. The mouse mono-specific serum was specific as it had no cross reaction with classical ALV-J strains. The result reveals that the tumor tissue suspension cells, the CEF infected by sarcoma supernatant, and the slice immunohistochemistry of the sarcoma showed positive results. The anti-fps mono-specific serum was prepared, and the detection method was established, which laid the foundation for the study of viral biological characteristics and mechanism of tumourgenesis of acute transforming avian leukosis/sarcoma virus containing v-fps oncogene.

The use of antigen ELISA to monitor the effectiveness of a tsetse control campaign in the upper Didessa valley, Western Ethiopia

International Nuclear Information System (INIS)

Tewelde, N.; Kebede, A.; Tsegaye, A.

1997-01-01

Blood and serum samples were collected from a tsetse free zone in the central highlands of Ethiopia. The samples were collected to determine the specificity and establish percentage positivity cut-off points of the antigen ELISA. Blood samples collected from these areas were negative for trypanosomosis using Standard Trypanosome Detection Methods (STDM). Ag-ELISA, in contrast, detected circulating trypanosomal antigens in 7.6% of the serum samples collected. Similarly, samples were collected from a tsetse infested zone in the upper Didessa valley, western Ethiopia, to assess the sensitivity of the Ag-ELISA. STDM detected trypanosomal infections in the range of 15.8 and 16.7% of blood samples from this zone. On the other hand, Ag-ELISA, indicated the presence of circulating trypanosomal antigens in 38.6% of serum samples tested. Moreover, Ag-ELISA was used to monitor the effectiveness of a tsetse control campaign in the upper Didessa valley. There were great differences in the prevalence rates of trypanosomosis, as revealed by the STDM and Ag-ELISA, between the tsetse controlled and tsetse infested zones of the upper Didessa valley. Generally, the Ag-ELISA revealed the presence of circulating trypanosomal antigens in only 43.7% of patent infections. Nevertheless, the test detected 318 more cases which were not diagnosed by any one of the STDM used. More interestingly, Ag-ELISA indicated the widespread presence of T. brucei in the cattle sampled in all zones. (author). 11 refs, 4 tabs

The use of antigen ELISA to monitor the effectiveness of a tsetse control campaign in the upper Didessa valley, Western Ethiopia

Energy Technology Data Exchange (ETDEWEB)

Tewelde, N; Kebede, A; Tsegaye, A [National Tsetse and Trypanosomiasis Investigation and Control Centre (NTTICC), Bedelle (Ethiopia)

1997-02-01

Blood and serum samples were collected from a tsetse free zone in the central highlands of Ethiopia. The samples were collected to determine the specificity and establish percentage positivity cut-off points of the antigen ELISA. Blood samples collected from these areas were negative for trypanosomosis using Standard Trypanosome Detection Methods (STDM). Ag-ELISA, in contrast, detected circulating trypanosomal antigens in 7.6% of the serum samples collected. Similarly, samples were collected from a tsetse infested zone in the upper Didessa valley, western Ethiopia, to assess the sensitivity of the Ag-ELISA. STDM detected trypanosomal infections in the range of 15.8 and 16.7% of blood samples from this zone. On the other hand, Ag-ELISA, indicated the presence of circulating trypanosomal antigens in 38.6% of serum samples tested. Moreover, Ag-ELISA was used to monitor the effectiveness of a tsetse control campaign in the upper Didessa valley. There were great differences in the prevalence rates of trypanosomosis, as revealed by the STDM and Ag-ELISA, between the tsetse controlled and tsetse infested zones of the upper Didessa valley. Generally, the Ag-ELISA revealed the presence of circulating trypanosomal antigens in only 43.7% of patent infections. Nevertheless, the test detected 318 more cases which were not diagnosed by any one of the STDM used. More interestingly, Ag-ELISA indicated the widespread presence of T. brucei in the cattle sampled in all zones. (author). 11 refs, 4 tabs.

Procedural and Declarative Memory in Children with and without Specific Language Impairment

Science.gov (United States)

Lum, Jarrad A. G.; Gelgic, Celin; Conti-Ramsden, Gina

2010-01-01

Background: Much evidence has accumulated to indicate memory deficits in children with specific language impairment. However, most research has focused on working memory impairments in these children. Less is known about the functioning of other memory systems in this population. Aims: This study examined procedural and declarative memory in young…

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

International Nuclear Information System (INIS)

Han, Hui; Peng, Ji-Run; Chen, Peng-Cheng; Gong, Lei; Qiao, Shi-Shi; Wang, Wen-Zhen; Cui, Zhu-Qingqing; Yu, Xin; Wei, Yu-Hua; Leng, Xi-Sheng

2011-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2011-08-05

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

Specificity of the bilingual advantage for memory: Examining cued recall, generalization, and working memory in monolingual, bilingual, and trilingual toddlers

Directory of Open Access Journals (Sweden)

Natalie Hiromi Brito

2014-12-01

Full Text Available The specificity of the bilingual advantage in memory was examined by testing groups of monolingual, bilingual, and trilingual 24-month-olds on tasks tapping cued recall, memory generalization and working memory. For the cued recall and memory generalization conditions, there was a 24-hour delay between time of encoding and time of retrieval. In addition to the memory tasks, parent-toddler dyads completed a picture-book reading task, in order to observe emotional responsiveness, and a parental report of productive vocabulary. Results indicated no difference between language groups on cued recall, working memory, emotional responsiveness, or productive vocabulary, but a significant difference was found in the memory generalization condition with only the bilingual group outperforming the baseline control group. These results replicate and extend results from past studies (Brito and Barr, 2012; 2014; Brito et al., in press and suggest a bilingual advantage specific to memory generalization.

Specificity of the bilingual advantage for memory: examining cued recall, generalization, and working memory in monolingual, bilingual, and trilingual toddlers.

Science.gov (United States)

Brito, Natalie H; Grenell, Amanda; Barr, Rachel

2014-01-01

The specificity of the bilingual advantage in memory was examined by testing groups of monolingual, bilingual, and trilingual 24-month-olds on tasks tapping cued recall, memory generalization and working memory. For the cued recall and memory generalization conditions, there was a 24-h delay between time of encoding and time of retrieval. In addition to the memory tasks, parent-toddler dyads completed a picture-book reading task, in order to observe emotional responsiveness, and a parental report of productive vocabulary. Results indicated no difference between language groups on cued recall, working memory, emotional responsiveness, or productive vocabulary, but a significant difference was found in the memory generalization condition with only the bilingual group outperforming the baseline control group. These results replicate and extend results from past studies (Brito and Barr, 2012, 2014; Brito et al., 2014) and suggest a bilingual advantage specific to memory generalization.

Local sleep spindle modulations in relation to specific memory cues

NARCIS (Netherlands)

Cox, R.; Hofman, W.F.; de Boer, M.; Talamini, L.M.

2014-01-01

Sleep spindles have been connected to memory processes in various ways. In addition, spindles appear to be modulated at the local cortical network level. We investigated whether cueing specific memories during sleep leads to localized spindle modulations in humans. During learning of word-location

Autobiographical Memory Specificity in Dissociative Identity Disorder

NARCIS (Netherlands)

Huntjens, R.J.C.; Wessel, I.; Hermans, D.; Minnen, A. van

2014-01-01

A lack of adequate access to autobiographical knowledge has been related to psychopathology. More specifically, patients suffering from depression or a history of trauma have been found to be characterized by overgeneral memory, in other words, they show a relative difficulty in retrieving a

Autobiographical memory specificity in dissociative identity disorder

NARCIS (Netherlands)

Huntjens, Rafaële J. C.; Wessel, Ineke; Hermans, Dirk; van Minnen, Agnes

A lack of adequate access to autobiographical knowledge has been related to psychopathology. More specifically, patients suffering from depression or a history of trauma have been found to be characterized by overgeneral memory, in other words, they show a relative difficulty in retrieving a

Antigen-specific tolerance of human alpha1-antitrypsin induced by helper-dependent adenovirus.

Science.gov (United States)

Cerullo, V; McCormack, W; Seiler, M; Mane, V; Cela, R; Clarke, C; Rodgers, J R; Lee, B

2007-12-01

As efficient and less toxic virus-derived gene therapy vectors are developed, a pressing problem is to avoid immune response to the therapeutic gene product. Secreted therapeutic proteins potentially represent a special problem, as they are readily available to professional antigen-presenting cells throughout the body. Some studies suggest that immunity to serum proteins can be avoided in some mouse strains by using tissue-specific promoters. Here we show that expression of human alpha1-antitrypsin (AAT) was nonimmunogenic in the immune-responsive strain C3H/HeJ, when expressed from helper-dependent (HD) vectors using ubiquitous as well as tissue-specific promoters. Coadministration of less immunogenic HD vectors with an immunogenic first-generation vector failed to immunize, suggesting immune suppression rather than immune stealth. Indeed, mice primed with HD vectors were tolerant to immune challenge with hAAT emulsified in complete Freund's adjuvant. Such animals developed high-titer antibodies to coemulsified human serum albumin, showing that tolerance was antigen specific. AAT-specific T cell responses were depressed in tolerized animals, suggesting that tolerance affects both T and B cells. These results are consistent with models of high-dose tolerance of B cells and certain other suppressive mechanisms, and suggest that a high level of expression from HD vectors can be sufficient to induce specific immune tolerance to serum proteins.

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.