Global Mapping of H3K4me1 and H3K4me3 Reveals the Chromatin State-Based Cell Type-Specific Gene Regulation in Human Treg Cells

Regulatory T cells (Treg) contribute to the crucial immunological processes of self-tolerance and immune homeostasis. Genomic mechanisms that regulate cell fate decisions leading to Treg or conventional T cells (Tconv) lineages and those underlying Treg function remain to be fully elucidated, especially at the histone modification level. We generated high-resolution genome-wide distribution maps of monomethylated histone H3 lysine 4 (H3K4me1) and trimethylated H3K4 (H3K4me3) in human CD4+CD25+FOXP3+ Tregs and CD4+CD25+FOXP3− activated (a)Tconv cells by DNA sequencing-by-synthesis. 2115 H3K4me3 regions corresponded to proximal promoters; in Tregs, the genes associated with these regions included the master regulator FOXP3 and the chemokine (C-C motif) receptor 7 (CCR7). 41024 Treg-specific H3K4me1 regions were identified. The majority of the H3K4me1 regions differing between Treg and aTconv cells were located at promoter-distal sites, and in vitro reporter gene assays were used to evaluate and identify novel enhancer activity. We provide for the first time a comprehensive genome-wide dataset of lineage-specific H3K4me1 and H3K4me3 patterns in Treg and aTconv cells, which may control cell type-specific gene regulation. This basic principle is likely not restricted to the two closely-related T cell populations, but may apply generally to somatic cell lineages in adult organisms

TRPA1 Activation-Induced Myelin Degradation Plays a Key Role in Motor Dysfunction After Intracerebral Hemorrhage

Intracerebral hemorrhage (ICH) is a devastating disease that is characterized by high morbidity and high mortality. ICH has an annual incidence of 10–30/100,000 people and accounts for approximately 10%–30% of all types of stroke. ICH mostly occurs at the basal ganglia, which is rich in nerve fibers; thus, hemiplegia is quite common in ICH patients with partial sensory disturbance and ectopic blindness. In the clinic, those symptoms are considered to originate from the white matter injury in the area, but the exact mechanisms are unknown, and currently, no effective drug treatments are available to improve the prognosis. Clarifying the mechanisms will contribute to the development of new treatment methods for patients. The transient receptor potential ankyrin 1 (TRPA1) channel is a non-selective cation channel that plays a role in inflammatory pain sensation and nociception and may be a potential regulator in emotion, cognition and social behavior. Here, we report that TRPA1 is involved in myelin damage and oxidative stress injury in a mouse ICH model. Intervention with the TRPA1 channel may be a new method to improve the motor function of patients in the early stage of ICH

Preparation of in-situ TiB2 reinforced aluminum matrix composites assisted by two steps of ultrasonic vibration

The TiB _2 /Al particle reinforced composites were prepared successfully through metal-salt reaction with different process conditions (mechanical stirring, one-stage and two-stages of ultrasonic vibration). It was usually taken more than 60 min to complete metal-salt reaction under mechanical stirring condition, lots of reinforcement agglomerations and residual intermediate such as Al _3 Ti was in the matrix. The reaction time was greatly shortened from 60 min to 5 min and particle agglomerations were eliminated successfully by the introduction of ultrasonic vibration at 850 °C. Through the introduction of ultrasonic vibration at 730 °C, not only most of the residual Al _3 Ti phase was broken or dissolved, but also the size of TiB _2 was refined. The composite prepared by two-stage ultrasonic vibration has the optimal improvements of yield strength and ultimate tensile strength, which increased by are 108% and 98% respectively, hardness increased 61.5%. When only introducing the first stage of UVT, the elongation decreased from 34% to 20% owning to lots of rod-like Al _3 Ti in the matrix, after the second stage of UVT, the elongation restored to 33%. The effects of ultrasonic vibration on phase transformation, microstructure, and mechanical properties were studied by x-ray diffraction (XRD), optical microscope (OM), scanning electron microscope (SEM) and Electron Backscattered Diffraction (EBSD). Moreover, the effects of Orowan strengthening, thermal expansion mismatch strengthening, and grain refinement strengthening on mechanical properties were also discussed

H-2 K(d)-Restricted Hepatitis B Virus-Derived Epitope Whose Specific CD8(+) T Lymphocytes Can Produce Gamma Interferon without Cytotoxicity

It is necessary to evaluate the cytokine secretion status of CD8(+) T lymphocytes and elucidate the factors influencing cytokine secretion, because the secretion of cytokines is also an important feature of CD8(+) T lymphocytes, and the cytokines usually play critical roles in the outcome of diseases. We showed here that peptide AYRPPNAPI, derived from the core antigen of hepatitis B virus (HBV), could bind to H-2 K(d) and induce primed splenocytes from HBcAg expression plasmid-immunized mice to produce gamma interferon (IFN-γ) in H-2 K(d)- and CD8-dependent manners instead of in a CD4-dependent manner. The induced cells were mainly CD3 and CD8 positive but had no cytotoxic effect on the corresponding target cells. When administered into HBV transgenic mice, these cells can decrease the serum HBV load without causing liver damage. These results suggest that this peptide is a special kind of CD8(+) T-cell epitope, for which specific CD8(+) T cells can produce IFN-γ when antigenic stimulation is encountered but which have no cytotoxic effect on the corresponding target cells both in vitro and in HBV transgenic mice. This phenomenon indicates initially that the functional mechanisms of CD8(+) T cells can be determined by their epitope specificity, which may be associated with the development of epitope-based immunotherapeutic approaches for infectious diseases and tumors

Inhibition of Mitochondrial ROS by MitoQ Alleviates White Matter Injury and Improves Outcomes after Intracerebral Haemorrhage in Mice

White matter injury (WMI) is an important cause of high disability after intracerebral haemorrhage (ICH). It is widely accepted that reactive oxygen species (ROS) contributes to WMI, but there is still no evidence-based treatment. Here, mitoquinone (MitoQ), a newly developed selective mitochondrial ROS scavenger, was used to test its neuroprotective potential. The data showed that MitoQ attenuated motor function deficits and motor-evoked potential (MEP) latency prolongation. Further research found that MitoQ blunted the loss of oligodendrocytes and oligodendrocyte precursor cells, therefore reduced demyelination and axon swelling after ICH. In the in vitro experiments, MitoQ, but not the nonselective antioxidant, almost completely attenuated the iron-induced membrane potential decrease and cell death. Mechanistically, MitoQ blocked the ATP deletion and mitochondrial ROS overproduction. The present study demonstrates that the selective mitochondrial ROS scavenger MitoQ may improve the efficacy of antioxidant treatment of ICH by white matter injury alleviation

Hepatitis B Virus Induces IL-23 Production in Antigen Presenting Cells and Causes Liver Damage via the IL-23/IL-17 Axis

<div><p>IL-23 regulates myriad processes in the innate and adaptive immune systems, and is a critical mediator of the proinflammatory effects exerted by Th17 cells in many diseases. In this study, we investigated whether and how hepatitis B virus (HBV) causes liver damage directly through the IL-23 signaling pathway. In biopsied liver tissues from HBV-infected patients, expression of both IL-23 and IL-23R was remarkably elevated. <i>In vivo</i> observations also indicated that the main sources of IL-23 were myeloid dendritic cells (mDCs) and macrophages. Analysis of <i>in vitro</i> differentiated immature DCs and macrophages isolated from healthy donors revealed that the HBV surface antigen (HBsAg) efficiently induces IL-23 secretion in a mannose receptor (MR)-dependent manner. Culture with an endosomal acidification inhibitor and the dynamin inhibitor showed that, upon binding to the MR, the HBsAg is taken up by mDCs and macrophages through an endocytosis mechanism. In contrast, although the HBV core antigen (HBcAg) can also stimulate IL-23 secretion from mDCs, the process was MR- and endocytosis-independent. In addition, IL-23 was shown to be indispensible for HBsAg-stimulated differentiation of naïve CD4⁺ T cells into Th17 cells, which were determined to be the primary source of IL-17 in HBV-infected livers. The cognate receptor, IL-17R, was found to exist on the hepatic stellate cells and mDCs, both of which might represent the potential target cells of IL-17 in hepatitis B disease. These data provide novel insights into a yet unrecognized mechanism of HBV-induced hepatitis, by which increases in IL-23 expression, through an MR/endocytosis-dependent or -independent manner, produce liver damage through the IL-23/IL-17 axis.</p></div

Hepatic IL-23/IL-23R is closely correlated with elevated IL-17, and IL-23R⁺ T cells are the main source of IL-17 in liver of CHB and ACLF patients.

<p>Relative mRNA expressions of IL-23, IL-23R and IL-17 in liver tissues infected by HBV were assayed by qPCR, and then Spearman's rank correlation was used to determine the correlation between relative mRNA expression of (<b>A</b>) IL-23 or (<b>B</b>) IL-23R and IL-17 in 51 CHB patients. Co-localization of IL-17 (red) with IL-23R (green) (<b>C</b>) in CHB patients' liver tissues was examined by fluorescence microscope. The right panels are enlarged images of the area in the left panel demarcated with the white dashed-line box. (<b>D</b>) Co-localization of IL-17 and IL-23R in PBMCs from hepatitis B patients is shown. PBMCs from patients with CHB were stimulated by PMA and ionomycin for 4 h in the presence of GolgiStop. A moiety of the stimulated PBMCs was measured by FCM to determine the frequency of IL-17⁺23R⁺ T cells in the total CD4⁺ T cells, with gating on CD3⁺CD8⁻ T cells. Co-localization of IL-17 (red) and IL-23R (green) in the smear of stimulated PBMCs was examined by confocal microscopy. The data shown are representative from one of the five CHB patients.</p

IL-23R expression is enhanced markedly and correlated with IL-23 level in liver tissues of CHB and ACLF patients.

<p>(<b>A</b>) Relative mRNA expression of IL-23R in liver tissue of various groups was analyzed by qRT-PCR. (<b>B</b>) Protein expression of IL-23R was analyzed by Western blot. Error bars indicate SD. **<i>P</i><0.01. (<b>C</b>) <i>In situ</i> expression of IL-23R in liver tissues was detected by immunohistochemical staining (magnification 100×). (<b>D</b>) The frequencies of intrahepatic IL-23R positive cells in patients with hepatitis B and health controls are shown. Error bars indicate SD. **<i>P</i><0.01; HPF, high power fields. (<b>E</b>) The correlation was analyzed between the expression of IL-23 and IL-23R in HBV infected liver tissue. <i>r</i> is the correlation coefficient and <i>P</i>-value is shown.</p

IL-23 production from DCs and macrophages stimulated by HBsAg is dependent upon endocytosis.

<p>(<b>A</b>) Monocytes were isolated from PBMCs of healthy blood donors and mDCs were induced by culturing in the presence of GM-CSF (50 ng/mL) and recombinant human IL-4 (5 ng/mL) for five days. Then, the mDCs were stimulated by HBsAg with or without ammonium chloride (10 µM), chloroquine (10 mM), Dynasore (80 µM), or HBsAg antibody (50 µg/mL) for 40 hours. ELISA was used to detect the concentration of IL-23 in the supernatants. The data represent one of three independent experiments with similar results. Error bars indicate SD. ***<i>P</i><0.001 vs. all other groups. DCs (<b>B</b>) and macrophages (<b>C</b>) were obtained from PBMCs for different stimulations and stainings. (<b>a</b>) Cells were stimulated with HBsAg (2 µg/mL) for 45 min and stained by isotype IgG (FITC). (<b>b</b>) Cells were directly stained with anti-MR mAb (FITC) without any stimulations. (<b>c</b>) Cells were stimulated with HBsAg (2 µg/mL) for 45 min and stained by anti-HBsAg mAb (FITC). (<b>d</b>) Cells were pretreated with MR-blocking antibody (10 µg/mL) for 30 min before the cells were stimulated by HBsAg (2 µg/mL) for 45 min and stained with anti-HBsAg (FITC). (<b>e</b>) Cells were pretreated with chloroquine (10 mM) for 10 min before stimulation by HBsAg (2 µg/mL) for 45 min and staining with anti-HBsAg (FITC). mDCs were stimulated by HBsAg (2 µg/mL) for 45 minutes, and the respective co-localizations of HBsAg with MR (<b>D</b>) or endosomal marker LysoTracker (<b>E</b>) were detected by confocal microscopy. (magnification 400×).</p