Search results for "bystander effect"
showing 9 items of 19 documents
A noninflammatory mRNA vaccine for treatment of experimental autoimmune encephalomyelitis.
2019
Precision therapy for immune tolerance Autoimmune diseases, such as multiple sclerosis (MS), result from a breach of immunological self-tolerance and tissue damage by autoreactive T lymphocytes. Current treatments can cause systemic immune suppression and side effects such as increased risk of infections. Krienke et al. designed a messenger RNA vaccine strategy that lacks adjuvant activity and delivers MS autoantigens into lymphoid dendritic cells. This approach expands a distinct type of antigen-specific effector regulatory T cell that suppresses autoreactivity against targeted autoantigens and promotes bystander suppression of autoreactive T cells against other myelin-specific autoantigen…
Novel mechanism for the radiation-induced bystander effect: nitric oxide and ethylene determine the response in sponge cells.
2006
Until now the bystander effect had only been described in vertebrates. In the present study the existence of this effect has been demonstrated for the phylogenetically oldest metazoan phylum, the Porifera. We used the demosponge Suberites domuncula for the experiments in the two-chamber-system. The lower dish contained irradiated "donor" cells (single cells) and the upper dish the primmorphs ("recipient" primmorphs). The "donor" cells were treated with UV-B light (40 mJ/cm2) and 100 microM hydrogen peroxide (H2O2), factors that exist also in the natural marine aquatic environment of sponges; these factors caused a high level of DNA strand breaks followed by a reduced viability of the cells.…
Cytomegalovirus Interleukin-10 Expression in Infected Cells Does Not Impair MHC Class I Restricted Peptide Presentation on Bystanding Antigen-Present…
2006
Human cytomegalovirus (HCMV) has evolved strategies to counteract its surveillance by the immune system. Mitigation of antiviral immune responses is considered critical for establishment of viral latency and for spread. Recently, a gene encoding an interleukin-10 homologue (cmvIL-10) has been discovered in the HCMV genome. Using recombinant cmvIL-10, several mostly immunosuppressive functions of the molecule have been described. However, the role of cmvIL-10 in the context of viral infection was not addressed. To be able to analyze this issue, we generated cmvIL- 10-negative viral mutants. Using these mutants, we tested whether the expression of cmvIL-10 by infected cells would render bysta…
Is It Possible to Measure the Role of the Bystander and the Victim of Bullying in Children? Construct Validity of Two Brief Pictorial Scales With IRT…
2021
The study's objective was to develop and validate the psychometric properties of two brief pictorial scales to evaluate the roles of bystanders and victims of bullying. A sample of 910 students was considered (49.6%, boys; 50.4%, girls) between the ages of 7 and 13 (M = 10, SD = 1.4). Both instruments present nine pictorial items representing two dimensions: physical bullying (items 1 to 4) and psychological bullying (items 5 to 9). An additional measure of anxiety was used to assess convergent validity. The Confirmatory Factorial Analysis shows that the two-dimensional oblique model, physical bullying and psychological bullying, presents a better fit to the bystander scale data (RMSEA = .…
The bone marrow stroma in hematological neoplasms—a guilty bystander
2011
In the setting of hematological neoplasms, changes in the bone marrow (BM) stroma might arise from pressure exerted by the neoplastic clone in shaping a supportive microenvironment, or from chronic perturbation of the BM homeostasis. Under such conditions, alterations in the composition of the BM stroma can be profound, and could emerge as relevant prognostic factors. In this Review, we delineate the multifaceted contribution of the BM stroma to the pathobiology of several hematological neoplasms, and discuss the impact of stromal modifications on the natural course of these diseases. Specifically, we highlight the involvement of BM stromal components in lymphoid and myeloid malignancies, a…
Clusterin: A Role in Cell Survival in the Face of Apoptosis?
1996
Clusterin is a multifunctional glycoprotein complex found in virtually all body fluids and on the surface of cells lining body cavities. Demonstrated and proposed functions include the transport of lipoproteins, the inhibition of complementmediated cell lysis and the modulation of cell-cell interactions. On the basis of its elevated expression in apoptotic tissues, it was originally proposed that the protein might be casually involved in apoptosis. Here, we discuss the recent data that, in contrast to the earlier notion, suggest that clusterin expression is not enhanced, but rather is down-regulated in the cells undergoing apoptosis and that its expression in the apoptotic tissue is restric…
The effect of social norms and the presence of bystanders on altruistic behavior
2016
In this chapter, prosocial behavior will be analyzed from a social psychology point of view, examining the theoretical contributions of the past ten years and highlighting the various interpretations that have been proposed. Specifically, the focus will be on the analysis of the motivations that characterize a person who behaves altruistically. Theoretical models that will be examined include those that consider the possibility of a genuine altruistic motivation, as well as those that hypothesize that true altruism does not exist. In fact, it will be shown how the motivation behind altruistic behavior has been interpreted differently by social psychologists as being either intrinsically ego…
Priming Effects on Commitment to Help and on Real Helping Behavior
2014
Years of research on bystander apathy have demonstrated that the physical presence of others can reduce the tendency to help individuals needing assistance. Recent research on the implicit bystander effect has suggested that simply imagining the presence of others can lead to less helping behavior on a subsequent unrelated task. The present study was designed to contribute to previous findings on the implicit bystander effect by demonstrating these effects on commitment to help and on real helping behavior, rather than simply on intentions to help. Studies 1a and 1b demonstrate that merely priming participants with the construct of being in a group at Time 1 created significantly less commi…
Prosocial priming and bystander effect in an online context.
2022
The present study tested the effect of priming the concept of prosociality on the bystander effect in an online environment. Participants were sent an e-mail requesting a plea for help and randomly assigned to one of four conditions in a 2 (Bystander: 0 vs. 14) × 2 (Priming: present vs. absent) design. The results demonstrated support for the study hypothesis. As expected, the virtual presence of many others significantly reduced e-mail responsiveness except when the request for help is preceded by prosocial priming. Implications of these findings for the literature on the bystander effect and priming are discussed.