Dysregulated Th17 cell responses underlie multiple inflammatory and autoimmune diseases, including autoimmune uveitis and its animal model, EAU. However, clinical trials targeting IL-17A in uveitis ...were not successful. Here, we report that Th17 cells were regulated by their own signature cytokine, IL-17A. Loss of IL-17A in autopathogenic Th17 cells did not reduce their pathogenicity and instead elevated their expression of the Th17 cytokines GM-CSF and IL-17F. Mechanistic in vitro studies revealed a Th17 cell-intrinsic autocrine loop triggered by binding of IL-17A to its receptor, leading to activation of the transcription factor NF-κB and induction of IL-24, which repressed the Th17 cytokine program. In vivo, IL-24 treatment ameliorated Th17-induced EAU, whereas silencing of IL-24 in Th17 cells enhanced disease. This regulatory pathway also operated in human Th17 cells. Thus, IL-17A limits pathogenicity of Th17 cells by inducing IL-24. These findings may explain the disappointing therapeutic effect of targeting IL-17A in uveitis.
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•IL-17A deficiency does not reduce the pathogenicity of Th17 cells in uveitis•IL-17A binds to its own receptor on Th17 cells, activating NF-κB•NF-κB induces IL-24 production, repressing the Th17 cytokine program through SOCS1/3•Silencing or depleting IL-24 in Th17 cells exacerbates neuroinflammation
Loss of IL-17A, the signature cytokine of autoreactive Th17 cells, unexpectedly did not diminish the pathogenicity of Th17 cells in neuroinflammatory disease. This report demonstrates that IL-17A represses the Th17 cytokine program, primarily IL-17F and GM-CSF, by inducing autocrine production of IL-24. Thus, IL-17A has a dual role in Th17 cells: pathogenic as well as regulatory.
During gene therapy trials, immune responses against adeno-associated virus (AAV) vectors are monitored by antibody assays that detect the humoral and T-cell mediated cellular responses to AAV ...vectors. T cell assays commonly utilize the collection of patients' peripheral blood mononuclear cells (PBMCs) and stimulation with AAV-derived overlapping peptides. We recently described that spontaneous deamidation coincides with T cell epitopes in AAV capsids and that spontaneous deamidation may enhance or decrease immunogenicity in some individuals. This raised the concern for false negative results of antibody detection and PBMC immune monitoring assays because these assays use wild-type (WT) AAV or WT peptides for T cell re-stimulation and these peptides may not re-activate T cells that were stimulated with deamidated AAV capsid. To investigate this concern, we modeled the scenario by expanding T cells with deamidated peptides and evaluated the cross-reactivity of expanded T cells to WT peptides. In the majority of samples, cells that were expanded with deamidated peptides and restimulated with WT peptide had significantly lowered IL-2 and IFN-γ production. Spiking the four deamidated peptides to the WT peptide pool used for re-stimulation, restored the signal and corrected the performance of the assay. We also evaluated the impact of deamidation on anti AAV binding antibodies and did not observe a major impact on seroprevalence detection of AAV9. These data indicate that a high level of deamidation in AAV therapy may result in underestimation or even failure to detect immune responses against WT peptides during cellular immune monitoring.
Experimental autoimmune uveitis (EAU), an animal model for severe intraocular inflammatory eye diseases, is mediated by both Th1 and Th17 cells. Here, we examined the capacity of TMP778, a selective ...inhibitor of RORγt, to inhibit the development of EAU, as well as the related immune responses. EAU was induced in B10.A mice by immunization with interphotoreceptor retinoid‐binding protein (IRBP). Treatment with TMP778 significantly inhibited the development of EAU, determined by histological examination. In addition, the treatment suppressed the cellular immune response to IRBP, determined by reduced production of IL‐17 and IFN‐γ, as well as lower percentages of lymphocytes expressing these cytokines, as compared to vehicle‐treated controls. The inhibition of IFN‐γ expression by TMP778 is unexpected in view of this compound being a selective inhibitor of RORγt. The observation was further confirmed by the finding of reduced expression of the T‐bet (Tbx21) gene, the transcription factor for IFN‐γ, by cells of TMP778‐treated mice. Thus, these data demonstrate the capacity of TMP778 to inhibit pathogenic autoimmunity in the eye and shed new light on its mode of action in vivo.
Treatment of mice with TMP778, a selective inhibitor of RORgt inhibits the generation of both Th1 and Th17 cells. The unexpected inhibition of Th1 cells is explained by fewer Th17 cells being available for the switch to the Th1 phenotype.
Context: Beetroot Beta vulgaris Linné (Chenopodiaceae), a vegetable usually consumed as a food or a medicinal plant in Europe, has been reported to have antioxidant and anti-inflammatory properties. ...Since the lymphohematopoietic system is the most sensitive tissue to ionizing radiation, protecting it from radiation damage is one of the best ways to decrease detrimental effects from radiation exposure.
Objective: In this study, we evaluated the radio-protective effects of beetroot in hematopoietic stem cells (HSCs) and progenitor cells.
Materials and methods: Beetroot extract was administered at a dose of 400 mg/mouse per os (p.o.) three times into C57BL/6 mice and, at day 10 after γ-ray irradiation, diverse molecular presentations were measured and compared against non-irradiated and irradiated mice with PBS treatments. Survival of beetroot-fed and unfed irradiated animal was also compared.
Results: Beetroot not only stimulated cell proliferation, but also minimized DNA damage of splenocytes. Beetroot also repopulated S-phase cells and increased Ki-67 or c-Kit positive cells in bone marrow. Moreover, beetroot-treated mice showed notable boosting of differentiation of HSCs into burst-forming units-erythroid along with increased production of IL-3. Also, beetroot-treated mice displayed enhancement in the level of hematocrit and hemoglobin as well as the number of red blood cell in peripheral blood. Beetroot diet improved survival rate of lethally exposed mice with a dose reduction factor (DRF) of 1.1.
Discussion and conclusion: These results suggest that beetroot has the potency to preserve bone marrow integrity and stimulate the differentiation of HSCs against ionizing radiation.
Despite the high safety profile demonstrated in clinical trials, the immunogenicity of adeno-associated virus (AAV)-mediated gene therapy remains a major hurdle. Specifically, T-cell-mediated immune ...responses to AAV vectors are related to loss of efficacy and potential liver toxicities. As post-translational modifications in T cell epitopes have the potential to affect immune reactions, the cellular immune responses to peptides derived from spontaneously deamidated AAV were investigated. Here, we report that highly deamidated sites in AAV9 contain CD4 T cell epitopes with a Th1 cytokine pattern in multiple human donors with diverse human leukocyte antigen (HLA) backgrounds. Furthermore, some peripheral blood mononuclear cell (PBMC) samples demonstrated differential T cell activation to deamidated or non-deamidated epitopes. Also, in vitro and in silico HLA binding assays showed differential binding to the deamidated or non-deamidated peptides in some HLA alleles. This study provides critical attributes to vector-immune-mediated responses, as AAV deamidation can impact the immunogenicity, safety, and efficacy of AAV-mediated gene therapy in some patients.
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Deamidation of AAV vectors occurs after long-term storage. Here, we show that deamidation of AAV-derived peptides can increase T cell immunogenicity in some individuals and decrease it in others. This subject-to-subject variability is associated with differential binding to some HLA molecules.
In this work, effects of YF3 addition on the formation and optical properties of Er3+ doped fluoride nanocrystals in glass–ceramics were studied. Results obtained from X-ray diffraction patterns, ...absorption spectra and emission spectra all showed that Y3+ ions promoted the preferential incorporation of Er3+ ions into the fluoride nanocrystals and decreased the effective concentration of Er3+ ions inside the fluoride nanocrystals. As a result, concentration dependent energy transfer processes were suppressed and efficiency of 2.73μm emission was improved.
•Reduced effective concentration of Er3+ ions in fluoride nanocrystals was observed.•Enhanced 2.73μm emission from Er3+ ions was observed in YF3 co-doped oxyfluoride glass–ceramics.•Double exponential decay of the 1.5μm emission from Er3+ ions was strongly dependent on the doping concentration of YF3.
Bearing pathologic and clinical similarities to human multiple sclerosis (MS), experimental autoimmune encephalomyelitis (EAE) is used as a murine model to test potential therapeutic agents for ...MS. Recently, we reported the protective effects of an acidic polysaccharide of Panax ginseng (APG) in C57BL/6 strain-dependent EAE, a model of primary progressive MS. In this study, we extend our previous findings on the therapeutic capacity of APG in relapsing-remitting EAE (rr-EAE), the animal model to closely mimic recurrent inflammatory demyelination lesions of relapsing-remitting MS. Treatments with APG led to a significant reduction of clinical symptoms and the relapse rate of EAE than vehicle treatments. Consistent with this, histological examination revealed that APG markedly modulated the infiltration of CD4Formula: see text T cells and CD11bFormula: see text macrophages into the spinal cord and the APG-treated CNS was devoid of demyelination and axonal damages. In addition, APG decreased the proliferation of peripheral PLP-reactive T cells and the production of pro-inflammatory factors such as IFN-Formula: see text, IL-17 and TNF-Formula: see text. The fact that APG can induce clinically beneficial effects to distinct types of EAE furthers our understanding on the basis of its immunosuppression in EAE and, possibly, in MS. Our results suggest that APG may serve as a new therapeutic agent for MS as well as other human autoimmune diseases, and warrants continued evaluation for its translation into therapeutic application.
Containing high concentration of vanadium served by the volcanic bedrock, Jeju ground water has long been known for various implicit health benefits including immune-promotion. Exposure to stress has ...been reported to be associated with immunosuppression such as reducing lymphocyte population or antibody production due to stress hormones. In this study, we aimed at evaluating the effects of Jeju ground water on chronically stressed mice. C57BL/6 mice were subjected to various stressors such as restraint stress, water swimming stress, heat stress, acoustic stress, and Jeju ground water was supplied for 28 days with two different concentrations, S1 (vanadium 15–20 μg/l, pH 8.3) and S2 (vanadium 20–25 μg/l, pH 8.5). Treatment with Jeju ground water increased CD4
+
CD8
−
or CD4
−
CD8
+
single-positive thymocytes. It also increased the proliferation of splenocytes and the populations of CD4
+
T cells, CD45R/B220
+
B cells, CD11b
+
macrophages or Gr-1
+
granulocytes in spleen. In addition, the production of IgG was increased in chronically stressed mice by treatment with Jeju ground water. These results suggest vanadium-rich Jeju ground water may be helpful in T cell development in thymus and immune cell proliferation and its function in spleen against chronic stress.
Lipocalin-2 (LCN2) plays an important role in cellular processes as diverse as cell growth, migration/invasion, differentiation, and death/survival. Furthermore, recent studies indicate that LCN2 ...expression and secretion by glial cells are induced by inflammatory stimuli in the central nervous system. The present study was undertaken to examine the regulation of LCN2 expression in experimental autoimmune encephalomyelitis (EAE) and to determine the role of LCN2 in the disease process. LCN2 expression was found to be strongly increased in spinal cord and secondary lymphoid tissues after EAE induction. In spinal cords astrocytes and microglia were the major cell types expressing LCN2 and its receptor 24p3R, respectively, whereas in spleens, LCN2 and 24p3R were highly expressed in neutrophils and dendritic cells, respectively. Furthermore, disease severity, inflammatory infiltration, demyelination, glial activation, the expression of inflammatory mediators, and the proliferation of MOG-specific T cells were significantly attenuated in Lcn2-deficient mice as compared with wild-type animals. Myelin oligodendrocyte glycoprotein-specific T cells in culture exhibited an increased expression of Il17a, Ifng, Rorc, and Tbet after treatment with recombinant LCN2 protein. Moreover, LCN2-treated glial cells expressed higher levels of proinflammatory cytokines, chemokines, and MMP-9. Adoptive transfer and recombinant LCN2 protein injection experiments suggested that LCN2 expression in spinal cord and peripheral immune organs contributes to EAE development. Taken together, these results imply LCN2 is a critical mediator of autoimmune inflammation and disease development in EAE and suggest that LCN2 be regarded a potential therapeutic target in multiple sclerosis.
Background: The role of LCN2 in EAE is not clear.
Results: LCN2 expression increased in EAE. Lcn2 deficiency attenuated EAE symptoms and pathology. LCN2 enhanced glial expression of inflammatory mediators and peripheral encephalitogenic T cell activation in vitro and in vivo.
Conclusion: Both central and peripheral LCN2 contributed to EAE development.
Significance: LCN2 can be targeted for treatment of multiple sclerosis.
Context: Hallabong (Citrus unshiu × C. sinensis) X C. reticulata) (Rutaceae) is a hybrid citrus cultivated in temperate regions of South Korea. Its fruit is well-known for pharmacological properties.
...Objective: This study examined the anti-inflammatory effect of 80% ethanol extract of Hallabong (HE) on concanavalin A (Con A)-stimulated splenocytes and mouse oedema model induced by 12-O-tetradecanoylphorbal acetate (TPA).
Materials and methods: Murine splenocytes treated with HE were stimulated with Con A (10 μg/mL, for 24 h) were evaluated for T-cell population and production of inflammatory cytokines IL-2, IL-4 and IFN-γ. Anti-inflammatory effect of topically applied HE (100 μg/20 μL) on TPA (4 μg/20 μL/ear)-induced ear oedema was investigated in mouse model.
Results: HE-treated Con A-stimulated murine splenocytes showed a marked decrease in CD44/CD62L
+
memory T-cell population, an important marker for anti-inflammatory activity, and a significant inhibition in the production of IL-2 and IFN-γ. HE treatment had reduced the mouse skin oedema (47%) and myeloperoxidase (MPO) activity significantly (40%) in TPA-challenged tissues. More importantly, immunohistochemical localization revealed the suppressed (p < 0.05) expression of inducible nitric oxide (iNOS), cyclooxygenase-2 (COX2). HE decreased the infiltration of CD3
+
T cells and F4/80
+
macrophages to the site of inflammation and a topical application of HE significantly suppressed the expression of TNF-α (20.2%).
Discussion and conclusion: A topical application of HE can exert a potential anti-inflammatory effect and HE can be explored further as a putative alternative therapeutic agent for inflammatory oedema.
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