MARCH5 promotes STING pathway activation by suppressing polymer formation of oxidized STING.

Stimulator of interferon genes (STING) is a core DNA sensing adaptor in innate immune signaling. STING activity is regulated by a variety of post-translational modifications (PTMs), including phosphorylation, ubiquitination, sumoylation, palmitoylation, and oxidation, as well as the balance between active and inactive polymer formation. It remains unclear, though, how different PTMs and higher order structures cooperate to regulate STING activity. Here, we report that the mitochondrial ubiquitin ligase MARCH5 (Membrane Associated Ring-CH-type Finger 5, also known as MITOL) ubiquitinates STING and enhances its activation. A long-term MARCH5 deficiency, in contrast, leads to the production of reactive oxygen species, which then facilitate the formation of inactive STING polymers by oxidizing mouse STING cysteine 205. We show that MARCH5-mediated ubiquitination of STING prevents the oxidation-induced STING polymer formation. Our findings highlight that MARCH5 balances STING ubiquitination and polymer formation and its control of STING activation is contingent on oxidative conditions.

Strong Anionic Repulsion for Fast Na Kinetics in P2-Type Layered Oxides.

An intriguing mechanism for enabling fast Na kinetics during oxygen redox (OR) is proposed to produce high-power-density cathodes for sodium-ion batteries (SIBs) based on the P2-type oxide models, Na2/3 [Mn6/9 Ni3/9 ]O2 (NMNO) and Na2/3 [Ti1/9 Mn5/9 Ni3/9 ]O2 (NTMNO) using the "potential pillar" effect. The critical structural parameter of NTMNO lowers the Na migration barrier in the desodiated state because the electrostatic repulsion of O(2p)O(2p) that occurs between transition metal layers is combined with the chemically stiff Ti4+ (3d)O(2p) bond to locally retain the strong repulsion effect. The NTMNO interlayer distance moderately decreases upon charging with oxygen oxidation, whereas that of NMNO decreases at a much faster rate, which can be explained by the dependence of OR activity on the coordination environment. Fundamental electrochemical experiments clearly indicate that the Ti doping of the bare material significantly improves its rate capability during OR, and detailed electrochemical and structural analyses show much faster Na kinetics for NTMNO than for NMNO. A systematic comparison of the two cathode oxides based on experiments and first-principles calculations establishes the "potential pillar" concept of not only improving the sluggish Na kinetics upon OR reaction but also harnessing the full potential of the anionic redox for high-power-density SIBs.

Intrinsic Origin of Nonhysteretic Oxygen Capacity in Conventional Na-Excess Layered Oxides.

An intriguing redox chemistry via oxygen has emerged to achieve high-energy-density cathodes and has been intensively studied for practical use of anion-utilization oxides in A-ion batteries (A: Li or Na). However, in general, the oxygen redox disappears in the subsequent discharge with a large voltage hysteresis after the first charge process for A-excess layered oxides exhibiting anion redox. Unlike these hysteretic oxygen redox cathodes, the two Na-excess oxide models Na2IrO3 and Na2RuO3 unambiguously exhibit nonhysteretic oxygen capacities during the first cycle, with honeycomb-ordered superstructures. In this regard, the reaction mechanism in the two cathode models is elucidated to determine the origin of nonhysteretic oxygen capacities using first-principles calculations. First, the vacancy formation energies show that the thermodynamic instability in Na2IrO3 increases at a lower rate than that in Na2RuO3 upon charging. Second, considering that the strains of Ir-O and Ru-O bonding lengths are softened after the single-cation redox of Ru4+/Ru5+ and Ir4+/Ir5+, the contribution in the oxygen redox from x = 0.5 to 0.75 is larger in Na1-xRu0.5O1.5 than that in Na1-xIr0.5O1.5. Third, the charge variations indicate a dominant cation redox activity via Ir(5d)-O(2p) for x above 0.5 in Na1-xIr0.5O1.5. Its redox participation occurred with the oxygen redox, opposite to the behavior in Na1-xRu0.5O1.5. These three considerations imply that the chemical weakness of Ir(5d)-O(2p) leads to a more redox-active environment of Ir ions and reduces the oxygen redox activity, which triggers the nonhysteretic oxygen capacity during (de)intercalation. This provides a comprehensive guideline for design of reversible oxygen redox capacities in oxide cathodes for advanced A-ion batteries.

The cGAS/STING/TBK1/IRF3 innate immunity pathway maintains chromosomal stability through regulation of p21 levels.

Chromosomal instability (CIN) in cancer cells has been reported to activate the cGAS-STING innate immunity pathway via micronuclei formation, thus affecting tumor immunity and tumor progression. However, adverse effects of the cGAS/STING pathway as they relate to CIN have not yet been investigated. We addressed this issue using knockdown and add-back approaches to analyze each component of the cGAS/STING/TBK1/IRF3 pathway, and we monitored the extent of CIN by measuring micronuclei formation after release from nocodazole-induced mitotic arrest. Interestingly, knockdown of cGAS (cyclic GMP-AMP synthase) along with induction of mitotic arrest in HeLa and U2OS cancer cells clearly resulted in increased micronuclei formation and chromosome missegregation. Knockdown of STING (stimulator of interferon genes), TBK1 (TANK-binding kinase-1), or IRF3 (interferon regulatory factor-3) also resulted in increased micronuclei formation. Moreover, transfection with cGAMP, the product of cGAS enzymatic activity, as well as add-back of cGAS WT (but not catalytic-dead mutant cGAS), or WT or constitutively active STING (but not an inactive STING mutant) rescued the micronuclei phenotype, demonstrating that all components of the cGAS/STING/TBK1/IRF3 pathway play a role in preventing CIN. Moreover, p21 levels were decreased in cGAS-, STING-, TBK1-, and IRF3-knockdown cells, which was accompanied by the precocious G2/M transition of cells and the enhanced micronuclei phenotype. Overexpression of p21 or inhibition of CDK1 in cGAS-depleted cells reduced micronuclei formation and abrogated the precocious G2/M transition, indicating that the decrease in p21 and the subsequent precocious G2/M transition is the main mechanism underlying the induction of CIN through disruption of cGAS/STING signaling.

Intracellular calcium is a rheostat for the STING signaling pathway.

Stimulator of IFN genes (STING) is essential for the DNA-sensing innate immune pathway. Recently, evidence is emerging that suggests STING also plays important roles in autoimmunity, cancer therapy, and senescence. Although a multitude of post-translational modifications that regulate the STING pathway have been discovered, the cellular events that guide STING translocation remain unclear. Here, we show, paradoxically, that both BAPTA-AM-mediated calcium depletion and ionomycin-induced calcium elevation suppress STING translocation and STING-mediated IFN-ß production. We demonstrate that the mitochondria fission mediator DRP1 is crucial for ionomycin-induced inhibition of IFN-ß production. Furthermore, knockout of DRP1 suppressed ionomycin-induced increases in calcium as well as mitochondrial fragmentation. Collectively, our findings reveal that the induction of STING signaling is contingent on a fine-tuning of intracellular calcium levels.

Systematic editing of synthetic RIG-I ligands to produce effective antiviral and anti-tumor RNA immunotherapies.

Retinoic acid-inducible gene I (RIG-I) recognizes double-stranded viral RNAs (dsRNAs) containing two or three 5' phosphates. A few reports of 5'-PPP-independent RIG-I agonists have emerged, but little is known about the molecular principles underlying their recognition. We recently found that the bent duplex RNA from the influenza A panhandle promoter activates RIG-I even in the absence of a 5'-triphosphate moiety. Here, we report that non-canonical synthetic RNA oligonucleotides containing G-U wobble base pairs that form a bent helix can exert RIG-I-mediated antiviral and anti-tumor effects in a sequence- and site-dependent manner. We present synthetic RNAs that have been systematically modified to enhance their efficacy and we outline the basic principles for engineering RIG-I agonists applicable to immunotherapy.

The Cooperative Role of CD326+ and CD11b+ Dendritic Cell Subsets for a Hapten-Induced Th2 Differentiation.

Dendritic cells (DCs) play a critical role in directing immune responses. Previous studies have identified a variety of DC subsets and elucidated their context-dependent functions that parallel those of effector Th cell subsets. However, little is known about the DC subsets responsible for differentiation of Th2 cells governing allergic contact dermatitis. In this study, we sought to determine the DC subset(s) that mediate Th2 priming in hapten-sensitized mice. We induced hapten-specific Th2 differentiation by sensitizing the mice with a single application of FITC dissolved in acetone:dibutyl phthalate, and traced the immune cells responsible for inducing the Th2 differentiation process at the primary stimulation, enabling us to track Th2 priming in vivo and to delete basophils and specific DC subsets. Our analysis revealed that IL-4 was produced in vivo as early as day 3 from CD4+ T cells with a single application of FITC. Basophils, despite producing IL-4 1 d earlier than T cells, were found to be dispensable for Th2 differentiation. Instead, we demonstrated that CD326+ dermal DCs and Langerhans cells were redundantly required for FITC-induced Th2 differentiation in vivo. Moreover, the cooperation of CD326+ Langerhans cells and CD11b+ DCs differentiated naive T cells into Th2 cells in vitro. Collectively, our findings highlight at least two DC subsets that play a critical role in polarizing naive CD4+ T cells to Th2 cells and support a two-hit model for Th2 differentiation.

Carbonyl cyanide 3-chlorophenylhydrazone (CCCP) suppresses STING-mediated DNA sensing pathway through inducing mitochondrial fission.

Besides its important role in innate immune response to DNA virus infection, the regulatory function of STING in autoimmunity and cancer is emerging. Recently, multiple mechanisms regulating the activity of the STING pathway have been revealed. Previous study showed that carbonyl cyanide 3-chlorophenylhydrazone (CCCP), the protonophore, inhibited STING-mediated IFN-ß production via disrupting mitochondrial membrane potential (MMP). However, how MMP dissipation leads to the suppression of the STING pathway remains unknown. Here, we show that CCCP inhibits activation of STING and its downstream signaling molecules, TBK1 and IRF3, but not STING translocation to the perinuclear region. We found that CCCP impairs the interaction between STING and TBK1 and concomitantly triggers mitochondria fission. Importantly, the knockout of the crucial mitochondria fission regulator Drp1 restored the STING activity, indicating that CCCP down-modulates the STING pathway through DRP1-mediated mitochondria fragmentation. Our findings highlight the coupling of the STING signaling platform to mitochondria dynamics.

Stimulator of IFN genes-mediated DNA-sensing pathway is suppressed by NLRP3 agonists and regulated by mitofusin 1 and TBC1D15, mitochondrial dynamics mediators.

The stimulator of IFN genes (STING)-mediated DNA-sensing pathway plays an important role in the innate immune response to pathogen infection, autoimmunity, and cancer; however, its regulatory mechanism has not been fully elucidated, and we do not yet know whether the STING pathway is counter-regulated by other innate immune pathways. Here, we show that the NLRP3-activating agonists, ATP and nigericin, prevent STING pathway activation in association with mitochondrial fragmentation; however, the suppression of the STING pathway and mitochondria fission were not dependent on NLRP3 or potassium efflux. Although nigericin-induced mitochondria fission was rescued by knockdown of either dynamin-related protein 1 or TBC1 domain family member 15 (TBC1D15), which are two distinct mitochondria fission regulators, only TBC1D15 restored the activity of the STING pathway, which indicates that inflammasome-activating signals curtail STING pathway activation via TBC1D15. Finally, we found that deficiency of mitofusin (MFN) 1, a mediator of mitochondrial fusion, inhibited STING pathway activation, which leads to a decrease in the induction of IFN-ß and its inducible gene, ISG56, in conjunction with diminished activation of the signaling molecules, TANK-binding kinase 1 and IFN regulatory factor 3, that are downstream of STING. These results highlight the crucial role of MFN1 in maintaining the competency of the STING pathway. Collectively, our findings reveal that mitochondrial dynamics regulators modulate the activation of the STING signaling pathway.-Kwon, D., Park, E., Kang, S.-J. Stimulator of IFN genes-mediated DNA-sensing pathway is suppressed by NLRP3 agonists and regulated by mitofusin 1 and TBC1D15, mitochondrial dynamics mediators.

Extra-Large Pore Mesoporous Silica Nanoparticles for Directing in Vivo M2 Macrophage Polarization by Delivering IL-4.

Over the past decade, mesoporous silica nanoparticles (MSNs) smaller than 200 nm with a high colloidal stability have been extensively studied for systemic drug delivery. Although small molecule delivery via MSNs has been successful, the encapsulation of large therapeutic biomolecules, such as proteins or DNA, is limited due to small pore size of the conventional MSNs obtained by soft-templating. Here, we report the synthesis of mesoporous silica nanoparticles with extra-large pores (XL-MSNs) and their application to in vivo cytokine delivery for macrophage polarization. Uniform, size-controllable XL-MSNs with 30 nm extra-large pores were synthesized using organic additives and inorganic seed nanoparticles. XL-MSNs showed significantly higher loadings for the model proteins with different molecular weights compared to conventional small pore MSNs. XL-MSNs were used to deliver IL-4, which is an M2-polarizing cytokine and very quickly degraded in vivo, to macrophages and polarize them to anti-inflammatory M2 macrophages in vivo. XL-MSNs induced a low level of reactive oxygen species (ROS) production and no pro-inflammatory cytokines in bone marrow-derived macrophages (BMDMs) and in mice injected intravenously with XL-MSNs. We found that the injected XL-MSNs were targeted to phagocytic myeloid cells, such as neutrophils, monocytes, macrophages, and dendritic cells. Finally, we demonstrated that the injection of IL-4-loaded XL-MSNs successfully triggered M2 macrophage polarization in vivo, suggesting the clinical potential of XL-MSNs for modulating immune systems via targeted delivery of various cytokines.

Case series of keratitis in poultry abattoir workers induced by exposure to the ultraviolet disinfection lamp.

BACKGROUND: An outbreak of eye diseases occurred among workers at a poultry abattoir in South Korea from December 2012 to June 2013. An epidemiological investigation of the causative agent was conducted. The workers were given a special health examination and workplace environmental monitoring was performed. Workers with ocular symptoms subsequently underwent an ophthalmic examination. CASE PRESENTAION: From a total of 41 workers, 26 (63.4 %) were diagnosed with keratoepitheliopathy by ophthalmic examination. Environmental monitoring of the workplace revealed that the ultraviolet (UV) apron-disinfection lamp had not been turning off at the set times, and so the workers' faces had been exposed to UV radiation. Effective radiation dose measurement showed a UV-B exposure of 7-30 µW/cm(2), and a UV-C exposure of 40-200 µW/cm(2); both values exceed the occupational exposure limits. The outbreak ceased after the lamp was repaired. CONCLUSIONS: This case shows that inappropriate use of the UV disinfection lamp can cause mass photokeratitis. In order to prevent this, the UV disinfection lamp must be checked regularly, workers must be educated on the health effects of UV radiation, and appropriate eye protection must be worn.

Serum prostate-specific antigen levels and type of work in tire manufacturing workers.

OBJECTIVES: This study measures serum prostate-specific antigen (PSA) levels in tire-manufacturing workers, and attempts to find occupational or non-occupational factors that related to their PSA levels. METHODS: A total of 1,958 healthy male workers (1,699 were production workers and 259 were office workers) took PSA measurement for analysis. RESULTS: After adjusting for age, body mass index, hypertension, regular exercise, alcohol drinking and smoking, which were significantly related to serum PSA levels or known related factors of serum PSA levels, the geometric mean PSA levels were significantly high in the office workers (p = 0.017), the older age group (p < 0.001), the group with hypertension (p = 0.046) and the group of individuals that do not exercise regularly (p = 0.015) and the office workers were more likely to have a serum PSA level of ≥4.0 (OR 7.73, 95% CI: 2.78-21.46) or 2.5 ng/mL (OR 2.74, 95% CI: 1.49-5.08). After stratifying by age and adjusting aforementioned covariates, office workers 50 years of age and older had the significantly higher geometric mean PSA levels (p = 0.017) and were more likely to have a serum PSA level of ≥4.0 ng/mL (OR 12.90, 95% CI: 3.65-45.64) or 2.5 ng/mL (OR 3.90, 95% CI: 1.64-9.25) than production workers 50 years of age and older. CONCLUSIONS: This study showed that serum PSA levels were significantly higher among the group with hypertension or the group of individuals that did not exercise regularly or group of office workers who were considered to have lesser physical activities.