Search results for "priming"
showing 10 items of 280 documents
In vivo γδ T Cell Priming to Mycobacterial Antigens by Primary Mycobacterium tuberculosis Infection and Exposure to Nonpeptidic Ligands
1999
The recognition of phosphorylated nonpeptidic microbial metabolites by Vγ9Vδ2 T cells does not appear to require the presence of MHC molecules or antigen processing, permitting rapid responses against microbial pathogens. These may constitute an important area of natural anti-infectious immunity. To provide evidence of their involvement in immune reactivities against mycobacteria, we measured the responsiveness of peripheral blood Vγ9Vδ2 T cells in children with primary Mycobacterium tuberculosis (MTB) infections. Peripheral blood mononuclear cells from 22 children with MTB infections and 16 positivity of tuberculin (PPD)-negative healthy children were exposed to nonpeptidic antigens in vit…
Induction of cytokine production in naive CD4+ T cells by antigen-presenting murine liver sinusoidal endothelial cells but failure to induce differen…
1999
Abstract Background & Aims: Murine liver sinusoidal endothelial cells (LSECs) constitutively express accessory molecules and can present antigen to memory Th1 CD4+ T cells. Using a T-cell receptor transgenic mouse line, we addressed the question whether LSECs can prime naive CD4+ T cells. Methods: Purified LSECs were investigated for their ability to induce activation and differentiation of naive CD4+ T cells in comparison with bone marrow–derived antigen-presenting cells and macrovascular endothelial cells. Activation of T cells was determined by cytokine production. LSECs were further studied for expression of interleukin (IL)-12 by reverse-transcription polymerase chain reaction, and the…
Uptake and presentation of exogenous antigen and presentation of endogenously produced antigen by skin dendritic cells represent equivalent pathways …
2008
Gene gun-mediated biolistic DNA vaccination with beta-galactosidase (betaGal)-encoding plasmid vectors efficiently modulated antigen-induced immune responses in an animal model of type I allergy, including the inhibition of immunoglobulin E (IgE) production. Here we show that CD4(+) as well as CD8(+) T cells from mice biolistically transfected with a plasmid encoding betaGal under the control of the fascin promoter (pFascin-betaGal) are capable of inhibiting betaGal-specific IgE production after adoptive transfer into naïve recipients. Moreover, suppression of IgE production was dependent on interferon (IFN)-gamma. To analyse the modalities of activation of CD4(+) and CD8(+) T cells regardi…
A CD40/CD40L feedback loop drives the breakdown of CD8+T-cell tolerance following depletion of suppressive CD4+T cells
2014
Dendritic cells (DCs) are the key APCs not only for the priming of naive T cells, but also for the induction and maintenance of peripheral T-cell tolerance. We have recently shown that cognate interactions between Foxp3(+) Tregs and steady-state DCs are crucial to maintain the tolerogenic potential of DCs. Using DIETER mice, which allow the induction of antigen presentation selectively on DCs without altering their maturation status, we show here that breakdown of CD8(+) T-cell tolerance, which ensues after depletion of suppressive CD4(+) T cells, is driven by a positive feedback loop in which autoreactive CD8(+) T cells activate DCs via CD40. These data identify ligation of CD40 on DCs as …
Endothelial Progenitor Cells: A Real Hope or an Unrealizable Dream? Which Measures or Strategies Are Necessary for making EPCs a clinical reality? Fo…
2017
It is the time to re-examine with new eyes the findings obtained to date on endothelial progenitor cells (EPCs), in order to eliminate the limitations and to shed light on such findings. This revision might be of help for reordering them and consequently to create a clear puzzle. This last might provide evidence relating to important aspects, including defining, isolating and characterizing EPCs by establishing standardized criteria for EPC research; discriminating between appropriate sub-populations for cell therapy; timing; dosing; priming of cells; and the delivery mode for different applications. Furthermore, influencing factors might also be identified, with the aim of focusing resourc…
Circulating specific antibodies enhance systemic cross-priming by delivery of complexed antigen to dendritic cells in vivo
2012
Increasing evidence suggests that antibodies can have stimulatory effects on T-cell immunity. However, the contribution of circulating antigen-specific antibodies on MHC class I cross-priming in vivo has not been conclusively established. Here, we defined the role of circulating antibodies in cross-presentation of antigen to CD8(+) T cells. Mice with hapten-specific circulating antibodies, but naϊve for the T-cell antigen, were infused with haptenated antigen and CD8(+) T-cell induction was measured. Mice with circulating hapten-specific antibodies showed significantly enhanced cross-presentation of the injected antigen compared with mice that lacked these antibodies. The enhanced cross-pre…
NF-κB inducing kinase (NIK) is an essential post-transcriptional regulator of T-cell activation affecting F-actin dynamics and TCR signaling
2018
NF-κB inducing kinase (NIK) is the key protein of the non-canonical NF-κB pathway and is important for the development of lymph nodes and other secondary immune organs. We elucidated the specific role of NIK in T cells using T-cell specific NIK-deficient (NIKΔT) mice. Despite showing normal development of lymphoid organs, NIKΔT mice were resistant to induction of CNS autoimmunity. T cells from NIKΔT mice were deficient in late priming, failed to up-regulate T-bet and to transmigrate into the CNS. Proteomic analysis of activated NIK-/- T cells showed de-regulated expression of proteins involved in the formation of the immunological synapse: in particular, proteins involved in cytoskeleton dy…
Implicit Interpersonal Attraction in Small Groups
2014
The present research investigated the nature and behavioral consequences of interpersonal attraction in small groups. In line with dual-process models of information processing, we studied the influence of implicit and explicit evaluations of interaction partners on actual friendly behavior in two social contexts. In two studies, 247 unacquainted same-sex participants ( N1 = 139; N2 = 108)—assigned to groups of four to six members—rated each other by completing a variant of the affective priming task to assess implicit interpersonal attraction and a self-report to measure explicit interpersonal attraction. Social relations analyses indicated that implicit and explicit interpersonal attract…
Beyond decomposition: Processing zero-derivations in English visual word recognition
2019
Four experiments investigate the effects of covert morphological complexity during visual word recognition. Zero-derivations occur in English in which a change of word class occurs without any change in surface form (e.g., a boat-to boat; to soak-a soak). Boat is object-derived and is a basic noun (N), whereas soak is action-derived and is a basic verb (V). As the suffix {-ing} is only attached to verbs, deriving boating from its base, requires two steps, boat(N) > boat(V) > boating(V), while soaking can be derived in one step from soak(V). Experiments 1 to 3 used masked priming at different prime durations to test matched sets of one- and two-step verbs for morphological (soaking-SOA…
Towards a methodological toolset for the psycholinguistics of translation
2021
Abstract The manuscript provides readers with a basic methodological toolset for experimental psycholinguistic studies on translation. Following a description of key methodological concepts and the rationale behind experimental designs in psycholinguistics, we discuss experimental paradigms adopted from bilingualism research, which potentially constitute a methodological foundation for studies investigating the psycholinguistics of translation. Specifically, we show that priming paradigms possess several inherent advantages which make them particularly suitable for research on translation. The manuscript critically discusses key methodological problems associated with such paradigms and ill…