Lack of FMRP in the retina: Evidence of a retinal specific transcriptomic profile.

Fragile X Syndrome (FXS), the most common inherited form of human intellectual disability, is a monogenic neurodevelopmental disorder caused by a loss-of-function mutation of the FMR1 gene. FMR1 is encoding the Fragile X Messenger Ribonucleo Protein (FMRP) an RNA-binding protein that regulates the translation of synaptic proteins. The absence of FMRP expression has many important consequences on synaptic plasticity and function, leading to the FXS clinical phenotype. Over the last decade, a visual neurosensorial phenotype had been described in the FXS patients as well as in the murine model (Fmr1-/ymice), characterized by retinal deficits associated to retinal perception alterations. However, although the transcriptomic profile in the absence of FMRP has been studied in the cerebral part of the central nervous system (CNS), there are no actual data for the retina which is an extension of the CNS. Herein, we investigate the transcriptomic profile of mRNA from whole retinas of Fmr1-/ymice. Interestingly, we found a specific signature of Fmrp absence on retinal mRNA expression with few common genes compared to other brain studies. Gene Ontology on these retinal specific genes demonstrated an enrichment in retinal development genes as well as in synaptic genes. These alterations could be linked to the reported retinal phenotype of the FXS condition. In conclusion, we describe for the first time, retinal-specific transcriptomic changes in the absence of FMRP.

NLRP6 negatively regulates type 2 immune responses in mice.

BACKGROUND: Inflammasomes are large protein complexes that assemble in the cytosol in response to danger such as tissue damage or infection. Following activation, inflammasomes trigger cell death and the release of biologically active forms of pro-inflammatory cytokines interleukin (IL)-1ß and IL-18. NOD-like receptor family pyrin domain containing 6 (NLRP6) inflammasome is required for IL-18 secretion by intestinal epithelial cells, macrophages, and T cells, contributing to homeostasis and self-defense against pathogenic microbes. However, the involvement of NLRP6 in type 2 lung inflammation remains elusive. METHODS: Wild-type (WT) and Nlrp6-/- mice were used. Birch pollen extract (BPE)-induced allergic lung inflammation, eosinophil recruitment, Th2-related cytokine and chemokine production, airway hyperresponsiveness, and lung histopathology, Th2 cell differentiation, GATA3, and Th2 cytokines expression, were determined. Nippostrongylus brasiliensis (Nb) infection, worm count in intestine, type 2 innate lymphoid cell (ILC2), and Th2 cells in lungs were evaluated. RESULTS: We demonstrate in Nlrp6-/- mice that a mixed Th2/Th17 immune responses prevailed following birch pollen challenge with increased eosinophils, ILC2, Th2, and Th17 cell induction and reduced IL-18 production. Nippostrongylus brasiliensis infected Nlrp6-/- mice featured enhanced early expulsion of the parasite due to enhanced type 2 immune responses compared to WT hosts. In vitro, NLRP6 repressed Th2 polarization, as shown by increased Th2 cytokines and higher expression of the transcription factor GATA3 in the absence of NLRP6. Exogenous IL-18 administration partially reduced the enhanced airways inflammation in Nlrp6-/- mice. CONCLUSIONS: In summary, our data identify NLRP6 as a negative regulator of type 2 immune responses.

STING agonist diABZI induces PANoptosis and DNA mediated acute respiratory distress syndrome (ARDS).

Stimulator of interferon genes (STING) contributes to immune responses against tumors and may control viral infection including SARS-CoV-2 infection. However, activation of the STING pathway by airway silica or smoke exposure leads to cell death, self-dsDNA release, and STING/type I IFN dependent acute lung inflammation/ARDS. The inflammatory response induced by a synthetic non-nucleotide-based diABZI STING agonist, in comparison to the natural cyclic dinucleotide cGAMP, is unknown. A low dose of diABZI (1 µg by endotracheal route for 3 consecutive days) triggered an acute neutrophilic inflammation, disruption of the respiratory barrier, DNA release with NET formation, PANoptosis cell death, and inflammatory cytokines with type I IFN dependent acute lung inflammation. Downstream upregulation of DNA sensors including cGAS, DDX41, IFI204, as well as NLRP3 and AIM2 inflammasomes, suggested a secondary inflammatory response to dsDNA as a danger signal. DNase I treatment, inhibition of NET formation together with an investigation in gene-deficient mice highlighted extracellular DNA and TLR9, but not cGAS, as central to diABZI-induced neutrophilic response. Therefore, activation of acute cell death with DNA release may lead to ARDS which may be modeled by diABZI. These results show that airway targeting by STING activator as a therapeutic strategy for infection may enhance lung inflammation with severe ARDS. STING agonist diABZI induces neutrophilic lung inflammation and PANoptosis A, Airway STING priming induce a neutrophilic lung inflammation with epithelial barrier damage, double-stranded DNA release in the bronchoalvelolar space, cell death, NETosis and type I interferon release. B, 1. The diamidobenzimidazole (diABZI), a STING agonist is internalized into the cytoplasm through unknown receptor and induce the activation and dimerization of STING followed by TBK1/IRF3 phosporylation leading to type I IFN response. STING activation also leads to NF-kB activation and the production of pro-inflammatory cytokines TNFα and IL-6. 2. The activation of TNFR1 and IFNAR1 signaling pathway results in ZBP1 and RIPK3/ASC/CASP8 activation leading to MLKL phosphorylation and necroptosis induction. 3. This can also leads to Caspase-3 cleavage and apoptosis induction. 4. Self-dsDNA or mtDNA sensing by NLRP3 or AIM2 induces inflammsome formation leading to Gasdermin D cleavage enabling Gasdermin D pore formation and the release mature IL-1ß and pyroptosis. NLRP3 inflammasome formation can be enhanced by the ZBP1/RIPK3/CASP8 complex. 5. A second signal of STING activation with diABZI induces cell death and the release of self-DNA which is sensed by cGAS and form 2'3'-cGAMP leading to STING hyper activation, the amplification of TBK1/IRF3 and NF-kB pathway and the subsequent production of IFN-I and inflammatory TNFα and IL-6. This also leads to IFI204 and DDX41 upregulation thus, amplifying the inflammatory loop. The upregulation of apoptosis, pyroptosis and necroptosis is indicative of STING-dependent PANoptosis.

The Dual Targeting of FcRn and FcγRs via Monomeric Fc Fragments Results in Strong Inhibition of IgG-Dependent Autoimmune Pathologies.

Novel molecules that directly target the neonatal Fc receptor (FcRn) and/or Fc gamma receptors (FcγRs) are emerging as promising treatments for immunoglobulin G (IgG)-dependent autoimmune pathologies. Mutated Fc regions and monoclonal antibodies that target FcRn are currently in clinical development and hold promise for reducing the levels of circulating IgG. Additionally, engineered structures containing multimeric Fc regions allow the dual targeting of FcRn and FcγRs; however, their tolerance needs to first be validated in phase I clinical studies. Here, for the first time, we have developed a modified monomeric recombinant Fc optimized for binding to all FcRns and FcγRs without the drawback of possible tolerance associated with FcγR cross-linking. A rational approach using Fc engineering allowed the selection of LFBD192, an Fc with a combination of six mutations that exhibits improved binding to human FcRn and FcγR as well as mouse FcRn and FcγRIV. The potency of LFBD192 was compared with that of intravenous immunoglobulin (IVIg), an FcRn blocker (Fc-MST-HN), and a trimeric Fc that blocks FcRn and/or immune complex-mediated cell activation through FcγR without triggering an immune reaction in several in vitro tests and validated in three mouse models of autoimmune disease.

Bromodomain and extraterminal (BET) protein inhibition of IgG/IgE production in murine B cells is counter-balanced by a strong Th2 bias.

OBJECTIVES: Inhibitors of bromodomain and extra terminal domain (BET) proteins are a new and growing class of anti-cancer drugs, which decrease oncogene expression by targeting superenhancers. Antibody production is another physiological process relying on superenhancers, and it remains to be clarified whether potential immunomodulatory properties of BET inhibitors might impact humoral immunity and allergy. METHODS: We thus evaluated humoral immune responses and their Th2 context in vitro and in vivo in mice following treatment with the classical BET-inhibitor JQ1. We quantified immunoglobulin (Ig) and antibody production by B cells either stimulated in vitro or obtained from immunised mice. JQ1 effects on class switching and activation-induced deaminase loading were determined, together with modifications of B, T follicular helper (Tfh) and T helper 2 (Th2) populations. JQ1 was finally tested in B-cell-dependent models of immune disorders. RESULTS: Bromodomain and extra terminal domain inhibition reduced class switching, Ig expression on B cells and antibody secretion and was correlated with decreased numbers of Tfh cells. However, JQ1 strongly increased the proportion of GATA3+ Th2 cells and the secretion of corresponding cytokines. In a mouse allergic model of lung inflammation, JQ1 did not affect eosinophil infiltration or mucus production but enhanced Th2 cytokine production and aggravated clinical manifestations. CONCLUSION: Altogether, BET inhibition thus interweaves intrinsic negative effects on B cells with a parallel complex reshaping of T-cell polarisation which can increase type 2 cytokines and eventually promote B-cell-dependent immunopathology. These opposite and potentially hazardous immunomodulatory effects raise concerns for clinical use of BET inhibitors in patients with immune disorders.

Chronic Pseudomonas aeruginosa Lung Infection Is IL-1R Independent, but Relies on MyD88 Signaling.

Cystic fibrosis is associated with chronic Pseudomonas aeruginosa colonization and inflammation. The role of MyD88, the shared adapter protein of the proinflammatory TLR and IL-1R families, in chronic P. aeruginosa biofilm lung infection is unknown. We report that chronic lung infection with the clinical P. aeruginosa RP73 strain is associated with uncontrolled lung infection in complete MyD88-deficient mice with epithelial damage, inflammation, and rapid death. Then, we investigated whether alveolar or myeloid cells contribute to heightened sensitivity to infection. Using cell-specific, MyD88-deficient mice, we uncover that the MyD88 pathway in myeloid or alveolar epithelial cells is dispensable, suggesting that other cell types may control the high sensitivity of MyD88-deficient mice. By contrast, IL-1R1-deficient mice control chronic P. aeruginosa RP73 infection and IL-1ß Ab blockade did not reduce host resistance. Therefore, the IL-1R1/MyD88 pathway is not involved, but other IL-1R or TLR family members need to be investigated. Our data strongly suggest that IL-1 targeted neutralizing therapies used to treat inflammatory diseases in patients unlikely reduce host resistance to chronic P. aeruginosa infection.

Aryl hydrocarbon receptor (Ahr)-dependent Il-22 expression by type 3 innate lymphoid cells control of acute joint inflammation.

The aryl hydrocarbon receptor (AHR) controls several inflammatory and metabolic pathways involved in various diseases, including the development of arthritis. Here, we investigated the role of AHR activation in IL-22-dependent acute arthritis using the K/BxN serum transfer model. We observed an overall reduction of cytokine expression in Ahr-deficient mice, along with decreased signs of joint inflammation. Conversely, we report worsened arthritis symptoms in Il-22 deficient mice. Pharmacological stimulation of AHR with the agonist VAG539, as well as injection of recombinant IL-22, given prior arthritogenic triggering, attenuated inflammation and reduced joint destruction. The protective effect of VAG539 was abrogated in Il-22 deficient mice. Finally, conditional Ahr depletion of Rorc-expressing cells was sufficient to attenuate arthritis, thereby uncovering a previously unsuspected role of AHR in type 3 innate lymphoid cells during acute arthritis.

NOD1 sensing of house dust mite-derived microbiota promotes allergic experimental asthma.

BACKGROUND: Asthma severity has been linked to exposure to gram-negative bacteria from the environment that are recognized by NOD1 receptor and are present in house dust mite (HDM) extracts. NOD1 polymorphism has been associated with asthma. OBJECTIVE: We sought to evaluate whether either host or HDM-derived microbiota may contribute to NOD1-dependent disease severity. METHODS: A model of HDM-induced experimental asthma was used and the effect of NOD1 deficiency was evaluated. Contribution of host microbiota was evaluated by fecal transplantation. Contribution of HDM-derived microbiota was assessed by 16S ribosomal RNA sequencing, mass spectrometry analysis, and peptidoglycan depletion of the extracts. RESULTS: In this model, loss of the bacterial sensor NOD1 and its adaptor RIPK2 improved asthma features. Such inhibitory effect was not related to dysbiosis caused by NOD1 deficiency, as shown by fecal transplantation of Nod1-deficient microbiota to wild-type germ-free mice. The 16S ribosomal RNA gene sequencing and mass spectrometry analysis of HDM allergen, revealed the presence of some muropeptides from gram-negative bacteria that belong to the Bartonellaceae family. While such HDM-associated muropeptides were found to activate NOD1 signaling in epithelial cells, peptidoglycan-depleted HDM had a decreased ability to instigate asthma in vivo. CONCLUSIONS: These data show that NOD1-dependent sensing of HDM-associated gram-negative bacteria aggravates the severity of experimental asthma, suggesting that inhibiting the NOD1 signaling pathway may be a therapeutic approach to treating asthma.

The Micro-Immunotherapy Medicine 2LEID Exhibits an Immunostimulant Effect by Boosting Both Innate and Adaptive Immune Responses.

This study aimed at evaluating the effects of the micro-immunotherapy medicine (MIM) 2LEID, both in vitro and in vivo, on several components of the innate and adaptive immune system. MIM increased the phagocytic activity of macrophages, and it augmented the expression of the activation markers CD69 and HLA-DR in NK cells and monocytes/macrophages, respectively. The effect of MIM was evaluated in a model of respiratory infection induced by influenza A virus administration to immunocompetent mice in which it was able to improve neutrophil recruitment within the lungs (p = 0.1051) and slightly increased the circulating levels of IgM (p = 0.1655). Furthermore, MIM stimulated the proliferation of CD3-primed T lymphocytes and decreased the secretion of the immunosuppressive cytokine IL-10 in CD14+-derived macrophages. Human umbilical vein endothelial cells were finally used to explore the effect of MIM on endothelial cells, in which it slightly increased the expression of immune-related markers such as HLA-I, CD137L, GITRL, PD-L1 and ICAM-1. In conclusion, the present study suggests that MIM might be a promising nonspecific (without antigen specificity) immunostimulant drug in preventing and early treating respiratory infections, but not only exclusively, as it would gently support several facets of the immune system and host defenses.

Oxidative Stress in Ozone-Induced Chronic Lung Inflammation and Emphysema: A Facet of Chronic Obstructive Pulmonary Disease.

Oxidative stress plays an important role in the pathogenesis of chronic obstructive pulmonary disease (COPD) caused by cigarette smoke and characterized by chronic inflammation, alveolar destruction (emphysema) and bronchiolar obstruction. Ozone is a gaseous constituent of urban air pollution resulting from photochemical interaction of air pollutants such as nitrogen oxide and organic compounds. While acute exposure to ozone induces airway hyperreactivity and neutrophilic inflammation, chronic ozone exposure in mice causes activation of oxidative pathways resulting in cell death and a chronic bronchial inflammation with emphysema, mimicking cigarette smoke-induced COPD. Therefore, the chronic exposure to ozone has become a model for studying COPD. We review recent data on mechanisms of ozone induced lung disease focusing on pathways causing chronic respiratory epithelial cell injury, cell death, alveolar destruction, and tissue remodeling associated with the development of chronic inflammation and AHR. The initial oxidant insult may result from direct effects on the integrity of membranes and organelles of exposed epithelial cells in the airways causing a stress response with the release of mitochondrial reactive oxygen species (ROS), DNA, and proteases. Mitochondrial ROS and mitochondrial DNA activate NLRP3 inflammasome and the DNA sensors cGAS and STING accelerating cell death pathways including caspases with inflammation enhancing alveolar septa destruction, remodeling, and fibrosis. Inhibitors of mitochondrial ROS, NLRP3 inflammasome, DNA sensor, cell death pathways, and IL-1 represent novel therapeutic targets for chronic airways diseases underlined by oxidative stress.

Hippocampal interleukin-33 mediates neuroinflammation-induced cognitive impairments.

BACKGROUND: Interleukin (IL)-33 is expressed in a healthy brain and plays a pivotal role in several neuropathologies, as protective or contributing to the development of cerebral diseases associated with cognitive impairments. However, the role of IL-33 in the brain is poorly understood, raising the question of its involvement in immunoregulatory mechanisms. METHODS: We administered recombinant IL-33 (rmIL-33) by intra-hippocampal injection to C57BL/6 J (WT) and IL-1αß deficient mice. Chronic minocycline administration was performed and cognitive functions were examined trough spatial habituation test. Hippocampal inflammatory responses were investigated by RT-qPCR. The microglia activation was assessed using immunohistological staining and fluorescence-activated cell sorting (FACS). RESULTS: We showed that IL-33 administration in mice led to a spatial memory performance defect associated with an increase of inflammatory markers in the hippocampus while minocycline administration limited the inflammatory response. Quantitative assessment of glial cell activation in situ demonstrated an increase of proximal intersections per radius in each part of the hippocampus. Moreover, rmIL-33 significantly promoted the outgrowth of microglial processes. Fluorescence-activated cell sorting analysis on isolated microglia, revealed overexpression of IL-1ß, 48 h post-rmIL-33 administration. This microglial reactivity was closely related to the onset of cognitive disturbance. Finally, we demonstrated that IL-1αß deficient mice were resistant to cognitive disorders after intra-hippocampal IL-33 injection. CONCLUSION: Thus, hippocampal IL-33 induced an inflammatory state, including IL-1ß overexpression by microglia cells, being causative of the cognitive impairment. These results highlight the pathological role for IL-33 in the central nervous system, independently of a specific neuropathological model.

Effects of Nintedanib in an Animal Model of Liver Fibrosis.

Systemic sclerosis can affect multiple internal organs, including the liver and lungs. Nintedanib, an antifibrotic approved for treatment of interstitial lung disease associated with systemic sclerosis, may have activity outside of the lungs. This study explored the effect of preventive and therapeutic nintedanib treatment in a 3-week carbon tetrachloride (CCL4)-induced (500 mg/kg/day twice weekly for 3 weeks) model of hepatic inflammation and fibrosis in C57Bl/6 mice (aged 8 weeks, n = 5 per group). Mice also received nintedanib (30 or 60 mg/kg/day) either each day for 21 days (preventive treatment) or from day 7 or day 14 (therapeutic treatment). Preventive nintedanib treatment at both doses significantly reduced CCL4-induced increases in myeloperoxidase (p < 0.01), hepatic collagen (p < 0.001), and interleukin (IL)-6 (p < 0.01) in the liver. Nintedanib also significantly reduced hepatic necrosis (p < 0.01 and p < 0.05), inflammation (p < 0.001 and p < 0.05), fibrosis (p < 0.001 and p < 0.05) and IL-1ß (p < 0.05 and p < 0.001) at both 30 and 60 mg/kg/day, respectively. Therapeutic treatment with nintedanib at 30 and 60 mg/kg/day significantly reduced CCL4-induced serum alanine aminotransferase from day 7 (p < 0.05 and p < 0.001) and day 14 (p < 0.01 and p < 0.05), respectively. Increases in tissue inhibitor of metalloproteinase-1 were significantly reduced by nintedanib at 60 mg/kg/day from day 7 only (p < 0.001), and nintedanib completely blocked elevation of IL-6 and IL-1ß levels regardless of dose or start of treatment (p < 0.05-p < 0.001). In both the preventive and therapeutic treatment schedules of the study, nintedanib treatment was beneficial in attenuating CCL4-induced pathology and reducing hepatic injury, inflammation, and fibrosis, demonstrating that nintedanib has antifibrotic and anti-inflammatory activity outside of the lungs.

Potential Role of the Micro-Immunotherapy Medicine 2LALERG in the Treatment of Pollen-Induced Allergic Inflammation.

In this study, we evaluated the efficacy of a micro-immunotherapy medicine (MIM), 2LALERG, in a preclinical model of allergic respiratory disease sensitized with birch pollen extract (BPE). BALB/c mice were immunized with BPE, or saline solution, and were then challenged. Micro-immunotherapy medicine pillules were diluted in water, and 3 doses (0.75; 1.5; 3 mg/mouse) were tested and compared to vehicle control (3 mg/mouse). Treatments and vehicle were orally administered by gavage for 10 days. Micro-immunotherapy medicine (0.75 mg/mouse) reduced the number of total cells as well as the levels of interleukin (IL)-13 in bronchoalveolar lavage fluid (BALF) compared to vehicle control. Eosinophils in BALF tended to be lower compared to vehicle group, and the difference is close to significance. Histological analysis in the lungs confirms a moderate effect of MIM (0.75 mg/mice) on inflammatory infiltration and mucus production. Serum levels of IL-5 in MIM (0.75 mg/mouse)-treated mice were lower compared to vehicle; IL-4 levels tended to be lower too. Total immunoglobulin E (IgE) decreased in serum of MIM (1.5 and 0.75 mg/mouse) groups compared to vehicle control. Micro-immunotherapy medicine exerted the highest effect at the lowest dose tested. Micro-immunotherapy medicine resolved the local and systemic inflammation, even if partially, in a model of pollen-induced, IgE-mediated inflammation.

Ozone-Induced Aryl Hydrocarbon Receptor Activation Controls Lung Inflammation via Interleukin-22 Modulation.

Airborne ozone exposure causes severe lung injury and inflammation. The aryl hydrocarbon Receptor (AhR) (1), activated in pollutant-induced inflammation, is critical for cytokine production, especially IL-22 and IL-17A. The role of AhR in ozone-induced lung inflammation is unknown. We report here that chronic ozone exposure activates AhR with increased tryptophan and lipoxin A4 production in mice. AhR-/- mice show increased lung inflammation, airway hyperresponsiveness, and tissue remodeling with an increased recruitment of IL-17A and IL-22-expressing cells in comparison to control mice. IL-17A- and IL-22-neutralizing antibodies attenuate lung inflammation in AhR-/- and control mice. Enhanced lung inflammation and recruitment of ILC3, ILC2, and T cells were observed after T cell-specific AhR depletion using the AhRCD4cre-deficient mice. Together, the data demonstrate that ozone exposure activates AhR, which controls lung inflammation, airway hyperresponsiveness, and tissue remodeling via the reduction of IL-22 expression.

The alternative cap-binding complex is required for antiviral defense in vivo.

Cellular response to environmental challenges requires immediate and precise regulation of transcriptional programs. During viral infections, this includes the expression of antiviral genes that are essential to combat the pathogen. Transcribed mRNAs are bound and escorted to the cytoplasm by the cap-binding complex (CBC). We recently identified a protein complex consisting of NCBP1 and NCBP3 that, under physiological conditions, has redundant function to the canonical CBC, consisting of NCBP1 and NCBP2. Here, we provide evidence that NCBP3 is essential to mount a precise and appropriate antiviral response. Ncbp3-deficient cells allow higher virus growth and elicit a reduced antiviral response, a defect happening on post-transcriptional level. Ncbp3-deficient mice suffered from severe lung pathology and increased morbidity after influenza A virus challenge. While NCBP3 appeared to be particularly important during viral infections, it may be more broadly involved to ensure proper protein expression.

Acute Respiratory Barrier Disruption by Ozone Exposure in Mice.

Ozone exposure causes irritation, airway hyperreactivity (AHR), inflammation of the airways, and destruction of alveoli (emphysema), the gas exchange area of the lung in human and mice. This review focuses on the acute disruption of the respiratory epithelial barrier in mice. A single high dose ozone exposure (1 ppm for 1 h) causes first a break of the bronchiolar epithelium within 2 h with leak of serum proteins in the broncho-alveolar space, disruption of epithelial tight junctions and cell death, which is followed at 6 h by ROS activation, AHR, myeloid cell recruitment, and remodeling. High ROS levels activate a novel PGAM5 phosphatase dependent cell-death pathway, called oxeiptosis. Bronchiolar cell wall damage and inflammation upon a single ozone exposure are reversible. However, chronic ozone exposure leads to progressive and irreversible loss of alveolar epithelial cells and alveoli with reduced gas exchange space known as emphysema. It is further associated with chronic inflammation and fibrosis of the lung, resembling other environmental pollutants and cigarette smoke in pathogenesis of asthma, and chronic obstructive pulmonary disease (COPD). Here, we review recent data on the mechanisms of ozone induced injury on the different cell types and pathways with a focus on the role of the IL-1 family cytokines and the related IL-33. The relation of chronic ozone exposure induced lung disease with asthma and COPD and the fact that ozone exacerbates asthma and COPD is emphasized.

Self-DNA Sensing in Lung Inflammatory Diseases.

Self-DNA sensing by the immune system has emerged as a key contributing response in the pathogenesis of cancer and autoimmune diseases. Recent studies have established that release of nuclear and mitochondrial DNA can also drive lung inflammatory diseases. Here, we review the latest advances on self-DNA sensing and signaling, the influence of these pathways on lung inflammation, and how these findings contribute to our understanding of basic mechanisms of innate immunity. Within a dozen DNA sensors, the cGAS/STING, inflammasomes and Toll-Like Receptor pathways are central to nucleic acid sensing. We propose a key role for the STING pathway in self-DNA sensing in inflammatory lung conditions, and identify major remaining questions that may further our understanding and potential to control self-DNA sensing and innate immune activation.