Neuropsychiatric complications of coronavirus disease 2019: Mount Sinai Health System cohort study.

Objective: To describe the frequency of neuropsychiatric complications among hospitalized patients with coronavirus disease 2019 (COVID-19) and their association with pre-existing comorbidities and clinical outcomes.

Methods: We retrospectively identified all patients hospitalized with COVID-19 within a large multicenter New York City health system between March 15, 2020 and May 17, 2021 and randomly selected a representative cohort for detailed chart review. Clinical data, including the occurrence of neuropsychiatric complications (categorized as either altered mental status [AMS] or other neuropsychiatric complications) and in-hospital mortality, were extracted using an electronic medical record database and individual chart review.

Chemokine receptor CCR9 suppresses the differentiation of CD4CD8αα intraepithelial T cells in the gut.

The chemokine receptor CCR9 equips T cells with the ability to respond to CCL25, a chemokine that is highly expressed in the thymus and the small intestine (SI). Notably, CCR9 is mostly expressed on CD8 but not on CD4 lineage T cells, thus imposing distinct tissue tropism on CD4 and CD8 T cells. The molecular basis and the consequences for such a dichotomy, however, have not been fully examined and explained.

The molecular basis and cellular effects of distinct CD103 expression on CD4 and CD8 T cells.

Integrin CD103 mediates the adhesion and tissue retention of T cells by binding to E-cadherin which is abundant on epithelial cells. Notably, CD103 is highly expressed on CD8 T cells but conspicuously absent on most CD4 T cells. The mechanism controlling such lineage-specific expression of CD103 remains unclear.

The Cytokine Receptor IL-7Rα Impairs IL-2 Receptor Signaling and Constrains the In Vitro Differentiation of Foxp3 Treg Cells.

IL-7 receptor signaling is essential for the generation and maintenance of conventional T cells. Immunosuppressive Foxp3 Treg cells, however, express uniquely low amounts of the IL-7-proprietary IL-7Rα so that they are impaired in IL-7 signaling. Because Treg cells depend on IL-2, the loss of IL-7Rα has been considered irrelevant for Treg cells.

SOCS3 is a suppressor of γc cytokine signaling and constrains generation of murine Foxp3 regulatory T cells.

SOCS3 is a cytosolic inhibitor of cytokine signaling that suppresses the activation of cytokine receptor-associated JAK kinases. Mechanistically, SOCS3 is recruited to a site in the cytokine receptors known as the SOCS3-interaction motif, and then binds JAK molecules to inhibit their kinase activity. The SOCS3-interaction motif is found in receptors of the gp130 cytokine family but mostly absent from other cytokine receptors, including γc.