Clinical Reasoning of a Generative Artificial Intelligence Model Compared With Physicians

This cross-sectional study assesses the ability of a large language model to process medical data and display clinical reasoning compared with the ability of attending physicians and residents.

Vitamin D constrains inflammation by modulating the expression of key genes on Chr17q12-21.1

Vitamin D possesses immunomodulatory functions and vitamin D deficiency has been associated with the rise in chronic inflammatory diseases, including asthma (Litonjua and Weiss, 2007). Vitamin D supplementation studies do not provide insight into the molecular genetic mechanisms of vitamin D-mediated immunoregulation. Here, we provide evidence for vitamin D regulation of two human chromosomal loci, Chr17q12-21.1 and Chr17q21.2, reliably associated with autoimmune and chronic inflammatory diseases. We demonstrate increased vitamin D receptor (Vdr) expression in mouse lung CD4+ Th2 cells, differential expression of Chr17q12-21.1 and Chr17q21.2 genes in Th2 cells based on vitamin D status and identify the IL-2/Stat5 pathway as a target of vitamin D signaling. Vitamin D deficiency caused severe lung inflammation after allergen challenge in mice that was prevented by long-term prenatal vitamin D supplementation. Mechanistically, vitamin D induced the expression of the Ikzf3-encoded protein Aiolos to suppress IL-2 signaling and ameliorate cytokine production in Th2 cells. These translational findings demonstrate mechanisms for the immune protective effect of vitamin D in allergic lung inflammation with a strong molecular genetic link to the regulation of both Chr17q12-21.1 and Chr17q21.2 genes and suggest further functional studies and interventional strategies for long-term prevention of asthma and other autoimmune disorders.

Protective Role of Rho Guanosine Diphosphate Dissociation Inhibitor, Ly-GDI, in Pulmonary Alveolitis

Growing evidences indicate that Ly-GDI, an inhibitory protein of Rho GTPases, plays an essential role in regulating actin cytoskeletal alteration which is indispensible for the process such as phagocytosis. However, the role of Ly-GDI in inflammation remains largely unknown. In the current study, we found that Ly-GDI expression was significantly decreased in the IgG immune complex-injured lungs. To determine if Ly-GDI might regulate the lung inflammatory response, we constructed adenovirus vectors that could mediate ectopic expression of Ly-GDI (Adeno-Ly-GDI). In vivo mouse lung expression of Ly-GDI resulted in a significant attenuation of IgG immune complex-induced lung injury, which was due to the decreased pulmonary permeability and lung inflammatory cells, especially neutrophil accumulation. Upon IgG immune complex deposition, mice with Ly-GDI over-expression in the lungs produced significant less inflammatory mediators (TNF-α, IL-6, MCP-1, and MIP-1α) in bronchoalveolar lavage fluid when compared control mice receiving airway injection of Adeno-GFP. Mechanically, IgG immune complex-induced NF-κB activity was markedly suppressed by Ly-GDI in both alveolar macrophages and lungs as measured by luciferase assay and electrophoretic mobility shift assay. These findings suggest that Ly-GDI is a critical regulator of inflammatory injury after deposition of IgG immune complexes and that it negatively regulates the lung NF-κB activity.

Maresin-1 regulates type 2 innate lymphoid cells and promotes generation of regulatory T cells to limit allergic inflammation (HYP2P.336)

Asthma is a chronic inflammatory disease that fails to resolve and is classically considered to be mediated by an overzealous CD4+Th2 immune response. Recently, a key role for type 2 innate lymphoid cells (ILC2s) was shown to have an important role in the initiation and amplification of allergic inflammation; however, mechanisms for ILC2 regulation remain to be determined. In this study, metabololipidomics of murine lungs identified temporal changes in the endogenous levels of docosahexaenoic acid (DHA)-derived pro-resolving mediator, maresin 1, (MaR1) during self-limited allergic inflammation to ovalbumin (OVA). MaR1 decreased after allergen challenge relative to levels found during sensitization, and subsequently increased during the resolution of inflammation. Exogenous administration of MaR1 reduced lung inflammation and ILC2 expression of IL-5 and IL-13 and increased amphiregulin. MaR1 augmented de novo generation of regulatory T cells (Tregs), which interacted with ILC2s to markedly suppress cytokine production in a TGF-β-dependent manner. Antibody-mediated depletion of Tregs interrupted MaR1 control of ILC2 expression of IL-13 in vivo. These results point to a pivotal role for Tregs in the control of ILC2s in a new proresolving mechanism engaged by MaR1.