Liver sinusoidal endothelial cells orchestrate NK cell recruitment and activation in acute inflammatory liver injury.

Liver sinusoidal endothelial cells (LSECs) rapidly clear lipopolysaccharide (LPS) from the bloodstream and establish intimate contact with immune cells. However, their role in regulating liver inflammation remains poorly understood. We show that LSECs modify their chemokine expression profile driven by LPS or interferon-γ (IFN-γ), resulting in the production of the myeloid- or lymphoid-attracting chemokines CCL2 and CXCL10, respectively, which accumulate in the serum of LPS-challenged animals. Natural killer (NK) cell exposure to LSECs in vitro primes NK cells for higher production of IFN-γ in response to interleukin-12 (IL-12) and IL-18. In livers of LPS-injected mice, NK cells are the major producers of this cytokine. In turn, LSECs require exposure to IFN-γ for CXCL10 expression, and endothelial-specific Cxcl10 gene deletion curtails NK cell accumulation in the inflamed livers. Thus, LSECs respond to both LPS and immune-derived signals and fuel a positive feedback loop of immune cell attraction and activation in the inflamed liver tissue.

The Dimensionality of Oral Language Ability: Evidence From Young Greek Children.

Purpose This study investigated component skills in oral language development utilizing and validating a new assessment battery in a large (N = 800) and representative sample of Greek students 4-7 years of age. Method All participants enrolled in public schools from four geographical regions (Attica, Thessaly, Macedonia, and Crete) that varied demographically (urban, semiurban, and rural). For the individualized language assessments, we utilized mobile devices (tablet PC) to ensure children's interest and joyful participation as well as reliable administration procedures across sites. Results by confirmatory factor analyses specified and validated five different models in each grade to identify the best conceptualization of language dimensionality in the respective age groups. Results Four-dimensional model provided a slightly better discriminant validity in language data of the preschool group. However, in kindergarten and first grades, the five-dimensional model had the best fit to the data to the four-dimensional. Conclusion These findings support the multidimensionality of oral language ability at this phase of development and increase of factor distinctiveness as children grow. Supplemental Material https://doi.org/10.23641/asha.12649214.