Generation of a Nur77 reporter mouse is used to demonstrate TCR signal strength during thymic selection and peripheral maintenance of conventional and nonconventional T cell subsets and presents a novel tool for studying antigen receptor activation in vivo.

No abstract

The orphan steroid receptor, Nur77, is thought to be a central participant in events leading to TCR-mediated clonal deletion of immature thymocytes. Interestingly, although both immature and mature murine T cell populations rapidly up-regulate Nur77 after TCR stimulation, immature CD4+CD8+ thymocytes respond by undergoing apoptosis, whereas their mature descendants respond by dividing. To understand these developmental differences in susceptibility to the proapoptotic potential of Nur77, we compared its regulation and compartmentalization and show that mature, but not immature, T cells hyperphosphorylate Nur77 in response to TCR signals. Nur77 resides in the nucleus of immature CD4+CD8+ thymocytes throughout the course of its expression and is not found in either the organellar or cytoplasmic fractions. However, hyperphosphorylation of Nur77 in mature T cells, which is mediated by both the MAPK and PI3K/Akt pathways, shifts its localization from the nucleus to the cytoplasm. The failure of immature CD4+CD8+ thymocytes to hyperphosphorylate Nur77 in response to TCR stimulation may be due in part to decreased Akt activity at this developmental stage.

No abstract

A second screen is defined as a second electronic device used by audience members while watching a television program. While second screen use during sport programming is on the rise, current understanding of second screen use and engagement is lacking. Thus, in an attempt to extend Niche Theory, the current study employs a structural equation model to further understanding of second screen use. Further, to better understand the outcome of second screen use, the current study examines the relationship between team identification, engagement, and self-efficacy with second screen use. Results suggest that engagement and self-efficacy both have a direct influence on attitude, whereas team identification and self-efficacy have a positive impact on engagement. Each of the hypothesized relationships is tested individually as well as in a theoretically constructed model of engagement and use.