13 research outputs found

    The impact of recent and long-term experience on access to word meanings: Evidence from large-scale internet-based experiments

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    Many word forms map onto multiple meanings (e.g., ‘‘ace”). The current experiments explore the extent to which adults reshape the lexical–semantic representations of such words on the basis of experience, to increase the availability of more recently accessed meanings. A naturalistic web-based experiment in which primes were presented within a radio programme (Experiment 1; N = 1800) and a lab-based experiment (Experiment 2) show that when listeners have encountered one or two disambiguated instances of an ambiguous word, they then retrieve this primed meaning more often (compared with an unprimed control condition). This word-meaning priming lasts up to 40 min after exposure, but decays very rapidly during this interval. Experiments 3 and 4 explore longer term word-meaning priming by measuring the impact of more extended, naturalistic encounters with ambiguous words: recreational rowers (N = 213) retrieved rowing related meanings for words (e.g., ‘‘feather”) more often if they had rowed that day, despite a median delay of 8 hours. The rate of rowing-related interpretations also increased with additional years’ rowing experience. Taken together these experiments show that individuals’ overall meaning preferences reflect experience across a wide range of timescales from minutes to years. In addition, priming was not reduced by a change in speaker identity (Experiment 1), suggesting that the phenomenon occurs at a relatively abstract lexical–semantic level. The impact of experience was reduced for older adults (Experiments 1, 3, 4) suggesting that the lexical–semantic representations of younger listeners may be more malleable to current linguistic experience

    A pilot study on the immunogenicity of dendritic cell vaccination during adjuvant oxaliplatin/capecitabine chemotherapy in colon cancer patients

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    Contains fulltext : 87604.pdf (publisher's version ) (Closed access)BACKGROUND: Dendritic cell (DC) vaccination has been shown to induce anti-tumour immune responses in cancer patients, but so far its clinical efficacy is limited. Recent evidence supports an immunogenic effect of cytotoxic chemotherapy. Pre-clinical data indicate that the combination of chemotherapy and immunotherapy may result in an enhanced anti-cancer activity. Most studies have focused on the immunogenic aspect of chemotherapy-induced cell death, but only few studies have investigated the effect of chemotherapeutic agents on the effector lymphocytes of the immune system. METHODS: Here we investigated the effect of treatment with oxaliplatin and capecitabine on non-specific and specific DC vaccine-induced adaptive immune responses. Stage III colon cancer patients receiving standard adjuvant oxaliplatin/capecitabine chemotherapy were vaccinated at the same time with keyhole limpet haemocyanin (KLH) and carcinoembryonic antigen (CEA)-peptide pulsed DCs. RESULTS: In 4 out of 7 patients, functional CEA-specific T-cell responses were found at delayed type hypersensitivity (DTH) skin testing. In addition, we observed an enhanced non-specific T-cell reactivity upon oxaliplatin administration. KLH-specific T-cell responses remained unaffected by the chemotherapy, whereas B-cell responses were diminished. CONCLUSION: The results strongly support further testing of the combined use of specific anti-tumour vaccination with oxaliplatin-based chemotherapy

    Maturation of monocyte-derived dendritic cells with Toll-like receptor 3 and 7/8 ligands combined with prostaglandin E2 results in high interleukin-12 production and cell migration

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    Dendritic cells (DC) are professional antigen-presenting cells of the immune system that play a key role in regulating T cell-based immunity. In vivo, the capacity of DC to activate T cells depends on their ability to migrate to the T cell areas of lymph nodes as well as on their maturation state. Depending on their cytokine-secreting profile, DC are able to skew the immune response in a specific direction. In particular, IL-12p70 producing DC drive T cells towards a T helper 1 type response. A serious disadvantage of current clinical grade ex vivo generated monocyte-derived DC is the poor IL-12p70 production. We have investigated the effects of Toll-like receptor (TLR)-mediated maturation on ex vivo generated human monocyte-derived DC. We demonstrate that in contrast to cytokine-matured DC, DC matured with poly(I:C) (TLR3 ligand) and/or R848 (TLR7/8 ligand) are able to produce vast amounts of IL-12p70, but exhibit a reduced migratory capacity. The addition of prostaglandin E2 (PGE2) improved the migratory capacity of TLR-ligand matured DC while maintaining their IL-12p70 production upon T cell encounter. We propose a novel clinical grade maturation protocol in which TLR ligands poly(I:C) and R848 are combined with PGE2 to generate DC with both high migratory capacity and IL-12p70 production upon T cell encounter

    Modeling the use of durational information in human spoken-word recognition

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    Contains fulltext : 86168.pdf (author's version ) (Open Access)13 p

    Effective migration of antigen-pulsed dendritic cells to lymph nodes in melanoma patients is determined by their maturation state

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    Dendritic cells are the professional antigen-presenting cells of the immune system. To induce an effective immune response, these cells should not only express high levels of MHC and costimulatory molecules but also migrate into the lymph nodes to interact with naĂŻve T cells. Here, we demonstrate that in vitro-generated mature, but not immature dendritic cells, efficiently migrate into the T-cell areas of lymph nodes of melanoma patients. This difference is confirmed by in vitro studies, in which immature dendritic cells are strongly adherent, whereas mature dendritic cells remain highly motile. Our present findings demonstrate that the ability of dendritic cells to mount a proper immune response correlates with their ability to migrate both in vitro and in viv

    In situ detection of antigen-specific T cells in cryo-sections using MHC class I tetramers after dendritic cell vaccination of melanoma patients.

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    Contains fulltext : 53002.pdf (publisher's version ) (Closed access)Application of tetrameric MHC class I-peptide complexes has significantly improved the monitoring of antigen-specific T cell immune responses in mouse models as well as in clinical studies. Especially MHC class I tetramer analysis of tumor-specific T cells in suspension or on thick vibratome sections from viable tissue has been proven extremely useful. Using the well-characterized mouse tyrosinase-related-protein-2 specific cytotoxic T cell (CTL) clone LP9, we now developed a method that allows for specific identification of T cells with MHC class I tetramers in 8 mum thick, chemically fixed cryosections. The protocol was validated in a murine influenza virus-infection model. Moreover, analysis of delayed type hypersensitivity (DTH) skin biopsies from melanoma patients vaccinated with peptide-loaded mature dendritic cells, revealed the presence and location of anti-tumor CTLs. The specificity of the CTLs detected in situ correlated with both the DTH challenge specificity and reactivity of cell suspensions derived from the same biopsies. Collectively, our data demonstrate that in situ MHC class I tetramer staining provides a valuable tool to reveal the presence and anatomical location of specific CTLs in frozen tissue following immune-based treatment strategies in cancer patients
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