15 research outputs found
Intergroup relations, racism and attribution of natural and cultural traits
This paper is framed by the general hypothesis according to which racism and xenophobia are today expressed not only in direct ways but also in indirect ways, in ways that protect people from being seen as transgressors of the anti-racist norm. From this general hypothesis we derived specific hypotheses on ingroup favouritism and outgroup derogation at the level of the attribution of natural and cultural traits. We tested the hypothesis that the groups that are object of racialization (black Africans) or etnhicization (people classified as ‘from eastern countries’ and as Muslims) can also be object of ontologisation. Our results show an ingroup favouritism and outgroup derogation of devalued outgroups or of outgroups with inferior social status. Results also show that an out group with a status equal to the one of the ingroup and with common imagined roots is not object of discrimination. Moreover, black Africans are the only group object of ontologisation
Cost of adaptation to a metalliferous environment for Thlaspi caerulescens: a field reciprocal transplantation approach.
• Field reciprocal transplantations of two metallicolous populations (Mpops) and two nonmetallicolous populations (NMpops) of Thlaspi caerulescens were performed here to determine the pattern of local adaptation and to assess the cost of adaptation of Mpops to a metalliferous environment (Menv). The role of herbivores as an important selective pressure in the nonmetalliferous environment (NMenv) was also examined. • Growth, survival, fitness, life cycle and herbivore consumption were monitored for each transplant for 2 yr. • Local adaptation of Mpops to their own environment was clearly demonstrated, as Mpops consistently outperformed NMpops in Menv. In NMenv, no advantage of NMpops over Mpops was detected. However, the fitness of Mpops was generally lower in NMenv than in Menv. Herbivore consumption appeared to be a significant selective pressure for Mpops in NMenv. • An imbalance of selective forces between Menv and NMenv probably explains the greater local adaptation of Mpops. Therefore, colonization of NMenv by Mpops appears possible. Although Mpops were able to survive and reproduce in NMenv, they nevertheless expressed a cost attributable in part to their higher susceptibility to herbivores. © The Authors (2007).FLWINinfo:eu-repo/semantics/publishe
HELIOS-expressing human CD8 T cells exhibit limited effector functions
Introduction: The transcription factor HELIOS is primarily known for its expression in CD4 regulatory T cells, both in humans and mice. In mice, HELIOS is found in exhausted CD8 T cells. However, information on human HELIOS+ CD8 T cells is limited and conflicting. Methods: In this study, we characterized by flow cytometry and transcriptomic analyses human HELIOS+ CD8 T cells. Results: These T cells primarily consist of memory cells and constitute approximately 21% of blood CD8 T cells. In comparison with memory HELIOS- T-BEThigh CD8 T cells that displayed robust effector functions, the memory HELIOS+ T-BEThigh CD8 T cells produce lower amounts of IFN-γ and TNF-α and have a lower cytotoxic potential. We wondered if these cells participate in the immune response against viral antigens, but did not find HELIOS+ cells among CD8 T cells recognizing CMV peptides presented by HLA-A2 and HLA-B7. However, we found HELIOS+ CD8 T cells that recognize a CMV peptide presented by MHC class Ib molecule HLA-E. Additionally, a portion of HELIOS+ CD8 T cells is characterized by the expression of CD161, often used as a surface marker for identifying TC17 cells. These CD8 T cells express TH17/TC17-related genes encoding RORgt, RORa, PLZF, and CCL20. Discussion: Our findings emphasize that HELIOS is expressed across various CD8 T cell populations, highlighting its significance beyond its role as a transcription factor for Treg or exhausted murine CD8 T cells. The significance of the connection between HELIOS and HLA-E restriction is yet to be understood