Biology subjects

Stehlik, C.

Publications and source records attributed to Stehlik, C..

4 recordsLinked to original sources

bioRxiv2026

IL-17RC signaling connects intestinal microbiota and neuroimmune interactions in atherosclerosis

While dysbiosis and inflammation were previously implicated in cardiovascular diseases, the circuits of how microbiota drives distant perivascular innervation, neuroinflammation and atherosclerosis remains unknown. Here, we report that IL-17RC signaling in intestine protects from atherosclerosis controlling intestinal barrier and microbiota, and loss of IL-17RC in intestinal epithelial cells alters microbiota, enhances perivascular innervation and aortic inflammation, augmenting the disease. Neuronal outgrowth is functionally dependent on microbiota and is essential for neuroinflammation and augmentation of atherosclerosis as chemical denervation reduces inflammation, macrophage activation and disease progression. Microbiota-dependent IL-17A producing {gamma}{delta} T cells accumulate in aorta to promote neuronal outgrowth and activation that can be reversed by {gamma}{delta} T cell blockade. Perivascular neuron activation is further dependent on cell autonomous IL-17 signaling as IL-17RC ablation in sympathetic neurons protected mice from microbiota-driven atherosclerosis. Together, our data illuminate how intestinal cytokine signaling distantly restrains neuroimmune interactions in aorta and uncovers a novel link between IL-17 signaling, microbiota, perivascular innervation and neuroimmune pro-inflammatory crosstalk instrumental for atherosclerosis progression. SummaryIL-17RC signaling regulates intestinal dysbiosis and perivascular neuronal outgrowth that modulates inflammation in atherosclerosis.

immunology↗

bioRxiv2025

cGAS-STING dependent type I IFN protects against Leptospira interrogans renal colonization in mice.

Leptospira interrogans is the major causative agent of leptospirosis. Humans, canines and livestock animals are susceptible to Leptospira species and can develop fulminant disease. Rodents serve as reservoir hosts in which the bacteria colonize the renal tubules and are excreted in the urine. The host immune response to Leptospira spp. remains poorly defined. We show that L. interrogans induces a robust type I interferon (IFN) response in human and murine macrophages that is dependent on the cytosolic dsDNA sensor Cyclic GMP-AMP Synthase (cGAS) and the Stimulator of IFN Genes (STING) signaling pathway. Further, we show that mice deficient in the IFN/{beta} receptor subunit 1 (IFNAR1) or STING had higher bacterial burdens and increased renal colonization following infection in vivo suggesting that cGAS-STING-driven type I IFN is required for the host defense against L. interrogans. These findings demonstrate the significance of cGAS-STING-dependent type I IFN signaling in mammalian innate immune responses to L. interrogans. Author SummaryLeptospirosis is a globally distributed zoonotic disease caused by spirochetes belonging to the genus Leptospira. While humans, livestock, and dogs can develop severe or even fatal illness upon infection, rodents typically serve as asymptomatic reservoir hosts. A defining feature of the leptospiral life cycle is the ability of the pathogen to colonize the kidney in these reservoir host species, leading to prolonged urinary shedding and environmental dissemination. Despite the significant global burden of leptospirosis, the innate immune pathways that detect this pathogen and prevent renal colonization remain poorly understood. In this study we demonstrate that L. interrogans induces a robust type I IFN cytokine response from macrophages. The induction of this type I IFN response is dependent on sensing cytosolic DNA by the cGAS-STING pathway. Using in vivo mouse models of L. interrogans infection we further show that activation of this pathway is required to control bacterial burdens and reduce long-term kidney colonization. This study is the first to demonstrate a critical role for cGAS-STING and type I IFN in controlling L. interrogans infection.

immunology↗

bioRxiv2025

CDDO-Imidazole regulates RBC alloimmunization to the KEL antigen by activating Nrf2

During red blood cell (RBC) transfusion, production of alloantibodies can promote significant hemolytic events. However, most transfusion recipients do not form anti-RBC alloantibodies. Identifying mechanisms that inhibit alloimmunization may lead to prophylactic interventions. One potential regulatory mechanism is activation of the transcription factor, nuclear factor erythroid-derived 2-like 2 (Nrf2), a master regulatory of antioxidant pathways. Pharmacologic Nrf2 activators improve sequelae of sickle cell disease in pre-clinical models. The Nrf2 activator, 1-[2-cyano-3-,12-dioxooleana-1,9(11)-dien-28-oyl]imidazole (CDDO-Im), suppresses production of inflammatory cytokines including type 1 interferons (IFN/{beta}), which have been implicated in promoting RBC alloimmunization in transfusion models. Thus, we tested the hypothesis that the Nrf2 activator, CDDO-Im, regulates RBC alloimmunization. Here, we report that CDDO-Im induced Nrf2 activated gene expression and suppressed poly(I:C)-induced IFN/{beta}-stimulated gene (ISG) expression in human macrophages and murine blood leukocytes. In addition, following transfusion of wildtype mice with RBCs expressing the KEL antigen, CDDO-Im treatment inhibited poly(I:C)-induced anti-KEL IgG production and promoted post-transfusion recovery of KEL+ RBCs, but failed to do so in Nrf2-/- mice. Results indicate that activation of the Nrf2 antioxidant pathway regulates RBC alloimmunization to the KEL antigen in a pre-clinical model. If findings translate to other models and human studies, Nrf2 activators may represent a potential prophylactic intervention to inhibit alloimmunization. Key PointsO_LIThe antioxidant pathway, Nrf2, inhibits anti-RBC alloantibody responses in a pre-clinical transfusion model. C_LIO_LINrf2 activation may represent a prophylactic strategy to inhibit RBC alloimmunization in transfusion recipients. C_LI

immunology↗

bioRxiv2024

Loss of TRIM21 drives UVB-induced systemic inflammation by regulating DNA-sensing pathways

BackgroundExposure of systemic lupus erythematosus (SLE) patients to ultraviolet light B (UVB) triggers local and systemic inflammation, with cytosolic DNA sensing and induction of type I interferons (IFNs) known to play a role. We previously identified TRIM21 as a negative regulator of DNA sensing and IFN expression. Here we explore the role of TRIM21 in regulating local and systemic responses following UVB exposure. MethodsWT (C57BL/6) and Trim21-/- mice were irradiated with UVB (100mJ/cm2) daily for 1 and 3 weeks, and UVB-induced inflammation in skin, blood, and spleen were analyzed by qPCR, histology, RNA sequencing and flow cytometry. Mechanistic studies were performed in bone marrow-derived macrophages (BMDMs) and mouse skin fibroblasts (MDF) from WT and Trim21-/- mice, and TRIM21-/-THP-1 cells. ResultsInfiltration of inflammatory cells and induction of type I IFN developed in UVB-exposed areas in both sets of mice, however Trim21-/-mice developed splenomegaly, enhanced total IgG levels and IFN-stimulated genes (ISG) in the blood and spleen. Enhanced basal and UVB-dependent Ifnb1 expression was observed in Trim21-/- BMDMs and MDFs, which was dependent on the cytosolic DNA sensing cGAS-STING pathway. Mechanistically, we found both degradation of DDX41 and STING levels were impaired in stimulated Trim21-/-BMDMs. ConclusionTaken together, our results indicate that TRIM21 protects against IFN induction at local and systemic levels through restricting STING signaling. Our finding that reduced levels of TRIM21 are observed in SLE patients with cutaneous involvement indicates a potential role for TRIM21 in guarding against systemic flare in SLE patients.

immunology↗