Adenosine induces IL-31 secretion by T-helper 2 cells: Implication for the effect of adenosine on atopic dermatitis and its therapeutic strategy.

Interleukin (IL)-31 is a recently-identified cytokine with a well-defined role in the pathogenesis of pruritus. Previously, we reported that adenosine upregulates IL-17A secretion by T-helper (Th)17 cells; however, the effect of adenosine on T cell subsets other than Th17 remains unclear. In this report, we show that adenosine upregulated production of IL-31 by cluster of differentiation (CD)4+ T cells. IL-31 was also upregulated by administration of an adenosine A2a receptor (A2aR) agonist (PSB0777), and adenosine-mediated IL-31 production was inhibited by an A2aR antagonist (istradefylline). Production of Th2-related cytokines (IL-4, IL-10, and IL-13) by CD4+ T cells showed the same tendency. Immune subset analyses revealed that adenosine upregulated IL-31 secretion by CD4+ chemokine receptor 3high T cells, and that Th2 cells differentiated from naïve CD4+ T cells. Administration of istradefylline to mice with atopic dermatitis suppressed the symptoms, suggesting that A2aR antagonists are an effective treatment for inflammatory dermatitis. Taken together, the results indicate that adenosine upregulates secretion of Th2-related cytokines by effector T cells in the skin, thereby triggering atopic dermatitis and associated pruritus.

Extracellular adenosine induces hypersecretion of IL-17A by T-helper 17 cells through the adenosine A2a receptor.

Extracellular adenosine, produced from ATP secreted by neuronal or immune cells, may play a role in endogenous regulation of inflammatory responses. Studies show that adenosine induces hypersecretion of IL-17A by CD4+ T cells upon treatment with an A2aR agonist (PSB0777), and that adenosine-mediated IL-17A hypersecretion is suppressed by the A2aR antagonist (Istradefylline) in humans. However, it is unclear whether A2aR downstream signaling is involved in IL-17A hypersecretion. Here, we show that inhibitors of adenyl cyclase (AC), protein kinase A (PKA), and cAMP response element binding protein (CREB) (which are signaling molecules downstream of the Gs protein coupled to the A2aR), suppress IL-17A production, suggesting that activation of A2aR signaling induces IL-17A production by CD4+ T cells. Furthermore, immune subset studies revealed that adenosine induces hypersecretion of IL-17A by T-helper (Th)17 cells. These results indicate that adenosine is an endogenous modulator of neutrophilic inflammation. Administration of an A2aR antagonist to mice with experimental autoimmune encephalomyelitis led to marked amelioration of symptoms. Thus, inhibitors of the novel A2aR-AC-cAMP-PKA-CREB signaling pathway for IL-17A hypersecretion by TCR-activated Th17 cells suppresses adenosine-mediated IL-17A production, suggesting that it may be an effective treatment for Th17-related autoimmune diseases.

Istradefylline, an adenosine A2a receptor antagonist, inhibits the CD4+ T-cell hypersecretion of IL-17A and IL-8 in humans.

Extracellular adenosine produced from ATP plays a role in energy processes, neurotransmission, and inflammatory responses. Istradefylline is a selective adenosine A2a receptor (A2aR) antagonist used for the treatment of Parkinson's disease. We previously showed using mouse models that adenosine primes hypersecretion of interleukin (IL)-17A via A2aR, which plays a role in neutrophilic inflammation models in mice. This finding suggests that adenosine is an endogenous modulator of neutrophilic inflammation. We, therefore, investigated the in vitro effect of istradefylline in humans. In the present study, using human peripheral blood mononuclear cells (PBMCs), we tested the effect of adenosine, adenosine receptor agonists and istradefylline on cytokine responses using mixed lymphocyte reaction (MLR), PBMCs, CD4+ T cells, and Candida albicans antigen (Ag)-stimulated PBMCs. We showed that adenosine and an A2aR agonist (PSB0777) promoted IL-17A and IL-8 production from human PBMCs, and istradefylline suppressed this response. In addition, istradefylline inhibited not only the IL-17A and IL-8 production induced by adenosine but also that from C. albicans Ag-stimulated PBMCs. These results indicate that adenosine-mediated IL-17A and IL-8 production plays a role in neutrophilic inflammation, against which istradefylline should be effective.

Signaling via dopamine and adenosine receptors modulate viral peptide-specific and T-cell IL-8 response in COVID-19.

B-cell but not T-cell responses have been extensively studied using peripheral blood mononuclear cells (PBMCs) obtained from patients with coronavirus disease 2019 (COVID-19). Our recent study showed that not only T-helper (Th) 17 but also Th1 cells directly produce interleukin (IL)-8, a major source of neutrophilic inflammation, which is also known to induce disseminated intravascular coagulation (DIC) in COVID-19 patients. Neutrophilic inflammation caused by IL-17A or IL-8 can be fatal; thus, therapeutic intervention is highly expected. The present study aimed to investigate the T-cell responses in the Japanese patients. We synthesized spike protein-derived 15-mer peptides that are expected to bind to HLA class II allelic products frequently observed in the Japanese population, and checked the T-cell responses in Japanese patients with COVID-19. We have found that (i) patients show marked IL-8 but not IL-17A responses; (ii) these responses are restricted by HLA-DR; and (iii) IL-8 responses are abrogated by a dopamine D2 like receptor (D2R) agonist, ropinirole, and an adenosine A2a receptor (A2aR) antagonist, istradefylline. Compounds used for the treatment of Parkinson's disease may ease DIC in COVID-19. (183 words).

Tannic acid acts as an agonist of the dopamine D2L receptor, regulates immune responses, and ameliorates experimentally induced colitis in mice.

Tannic acid (TA) is an herbal polyphenol containing a galloyl group that has been prescribed to treat gastroenteritis, diarrhea, and irritable bowel syndrome. TA has anti-inflammatory, anti-cancer, and anti-viral properties; however, the molecular mechanisms of these potential therapeutic effects are still largely unknown. Here, we examined the ability of TA to induce anti-inflammatory responses. TA was found to be an agonist of the dopamine D2L receptor. TA reduced interferon (IFN)-γ and interleukin (IL)-1ß secretion but upregulated tumor necrosis factor α and IL-10 secretion from lipopolysaccharide (LPS)-stimulated mouse splenocytes. TA also reduced IFN-γ secretion but enhanced IL-10 secretion from anti-cluster of differentiation (CD) 3/CD28 antibody-stimulated splenocytes. An immune subset study confirmed that TA regulated cytokine secretion by various types of immune cells in the context of stimulation with LPS or anti-CD3/CD28 antibodies. Administration of TA to mice with experimentally induced colitis strikingly suppressed weight loss, colon shrinkage, and IL-17 secretion from mesenteric lymph node lymphocytes in response to CD3/CD28 stimulation. These data suggest that TA suppresses inflammatory responses in colitis by regulating cytokine secretion by immune cells in the colon.

Identification of the novel 3' UTR sequences of human IL-21 mRNA as potential targets of miRNAs.

Hepatitis B virus (HBV) infection is a leading cause of hepatocellular carcinoma worldwide. However, the strategy of HBV to escape from the host immune system remains largely unknown. In this study, we examined extracellular vesicles (EVs) secreted from human hepatocytes infected with HBV. EVs includeing exosomes are nano-size vesicles with proteins, mRNAs, and microRNAs (miRNAs), which can be transmitted to different cells. We found that 104 EV associated miRNAs were increased in hepatocytes more than 2-fold by HBV infection. We then selected those that were potentially implicated in immune regulation. Among them, five HBV-induced miRNAs were found to potentially target multiple sequences in the 3'UTR of IL-21, a cytokine that induces anti-viral immunity. Moreover, expression of a reporter gene with the 3' UTR of human IL-21 mRNA was suppressed by the five miRNAs individually. Finally, IL-21 expression in cloned human T cells was down-regulated by the five miRNAs. Collectively, this study identified the novel 3' UTR sequences of human IL-21 mRNA and potential binding sites of HBV-induced EV-miRNAs.

T-Cell Responses to Tyrosinase-Derived Self-Peptides in Patients with Leukoderma Induced by Rhododendrol: Implications for Immunotherapy Targeting Melanoma.

BACKGROUND: Rhododendrol, a phenolic compound contained in lightening/whitening cosmetics, can bind and inhibit tyrosinase and was reported to induce leukoderma in Japan. Only 2% of the cosmetics users are affected, and tacrolimus is effective in treatment of the condition. OBJECTIVE: To test the hypothesis that the disease is an autoimmune disorder. METHODS: Short-term T-cell lines were established using peripheral blood mononuclear cells from 8 patients with human melanoma-associated and tyrosinase-derived synthetic peptides. The effects of rhododendrol on melanoma immunization were also examined. RESULTS: Seven out of 8 patients were positive for HLA-DR4. Both class I- and class II-restricted and tyrosinase peptide-specific T-cell responses were observed. Immunization of mice with rhododendrol-treated and irradiated B16 melanoma cells successfully delayed the growth of melanoma cells in vivo. CONCLUSION: Rhododendrol-induced leukoderma is an autoimmune disorder, with rhododendrol as an environmental factor and HLA-DR4 as a genetic factor. Rhododendrol might be effective in treating melanomas.

Berberine is a dopamine D1- and D2-like receptor antagonist and ameliorates experimentally induced colitis by suppressing innate and adaptive immune responses.

Berberine is an herbal alkaloid with various biological activities, including anti-inflammatory and antidepressant effects. Here, we examined the effects of berberine on dopamine receptors and the ensuing anti-inflammatory responses. Berberine was found to be an antagonist at both dopamine D1- and D2-like receptors and ameliorates the development of experimentally induced colitis in mice. In lipopolysaccharide-stimulated immune cells, berberine treatment modified cytokine levels, consistent with the effects of the dopamine receptor specific antagonists SCH23390 and L750667. Our findings indicate that dopamine receptor antagonists suppress innate and adaptive immune responses, providing a foundation for their use in combatting inflammatory diseases.

Coenzyme A contained in mothers' milk is associated with the potential to induce atopic dermatitis.

T(h)2 adjuvant activity can be qualitatively and quantitatively evaluated using a mixed lymphocyte reaction and by changes in the intracellular cyclic adenosine 3',5'-monophosphate concentration, using human dendritic cells in vitro. The current study shows that mothers, whose children (n = 55) developed atopic dermatitis (AD) within 6 months after birth, often demonstrate a higher T(h)2 adjuvant activity in their milk, in comparison to those whose children did not develop such symptoms. Such an activity was recovered in a liquid phase of mothers' milk and was eluted as a single fraction by reversed-phase HPLC. Further analysis of this fraction by mass spectrometry showed that signals originating from a factor with a molecular weight of 767.53 are observed, exclusively in milk with a high T(h)2 adjuvant activity. The mass is exactly that of Coenzyme A (CoA), and indeed, a low concentration of CoA exhibited T(h)2 adjuvant activity both in vitro and in vivo. Moreover, mesenteric lymph node non-T cells obtained from mice that were orally treated with CoA led allogeneic naive CD4(+) T cells to differentiate into T(h)2. Furthermore, the oral administration of CoA induced rough skin, hyperplasia of the epidermis, hypergranulosis in the spinous layer and the thickening of the stratum in mice. These data collectively indicate that some of the patients with AD were exposed to mothers' milk carrying high T(h)2 adjuvant activity right after birth, which may be attributable to presence of CoA contained in the milk.

Curdlan induces DC-mediated Th17 polarization via Jagged1 activation in human dendritic cells.

BACKGROUND: Th17-inducing activity is carried by certain polysaccharides such as beta-glucan derived from Candia albicans. Our previous studies have shown that Th1- and Th2-inducing activities can be qualitatively evaluated by the expression patterns of Notch ligand isoforms, using human monocyte-derived dendritic cells (Mo-DCs) and some leukemic cell lines such as THP-1. The association of Th17-inducing activities with Notch ligand expression patterns has been unclear. METHODS: Mo-DCs from healthy volunteers were co-cultured with HLA-DR-nonshared allogeneic CD4+ naïve T cells to induce a mixed lymphocyte reaction, in the presence of adjuvants, such as curdlan. Culture supernatants were assayed for IFNgamma, IL-5 and IL-17 by an enzyme-linked immunosorbent assay (ELISA). Notch ligand expression on Mo-DCs and THP-1 cells was evaluated by using RT-PCR. RESULTS: The present study shows that curdlan, one of the beta-glucans, has the ability to induce DC-mediated Th17 differentiation. It is also interesting to note that Jagged1 mRNA in Mo-DCs and THP-1 cells is up-regulated by curdlan. Furthermore, polyclonal anti-Jagged1 antibody inhibited such DC-mediated Th17 differentiation. CONCLUSIONS: This study suggests that curdlan induces human DC-mediated Th17 polarization via Jagged1 activation in DCs.

11-Tungstophosphate with iron(II) and hydrogen peroxide efficiently detached bacterial biofilm.

An attempt was made to detach bacterial biofilm, formed by Staphylococcus epidermidis, by using hydrogen peroxide (H(2)O(2)) and tungsten compounds. When iron(II) (Fe(2+)) was mixed with undecatungstophosphate ([PW(11)O(39)](7-)) and then H(2)O(2), the resulting mixture was able to totally remove the biofilm probably because of co-generation of (1)O(2) and .OH. A mixture of undecatungstosilicate ([SiW(11)O(39)](8-)) and Fe(2+) (or Cu(2+)) also gave a good result, but their catalytic activities for producing .OH (or (1)O(2)) were rather weak. An electron microscopic study showed that almost nothing was visible on the surface of a biofilm-coated glass after treatment with 1mM [PW(11)O(39)](7-)+1 mM Fe(2+) and 500 mM H(2)O(2) (incubated for 1 h at 37 degrees C).

Dopamine released by dendritic cells polarizes Th2 differentiation.

A major neurotransmitter dopamine transmits signals via five different seven transmembrane G protein-coupled receptors termed D1-D5. It is now evident that dopamine is released from leukocytes and acts as autocrine or paracrine immune modulator. However, the role of dopamine for dendritic cells (DCs) and T(h) differentiation remains unclear. We herein demonstrate that human monocyte-derived dendritic cells (Mo-DCs) stored dopamine in the secretary vesicles. The storage of dopamine in Mo-DCs was enhanced by forskolin and dopamine D2-like receptor antagonists via increasing cyclic adenosine 3',5'-monophosphate (cAMP) formation. Antigen-specific interaction with naive CD4(+) T cells induced releasing dopamine-including vesicles from Mo-DCs. In naive CD4(+) T cells, dopamine dose dependently increased cAMP levels via D1-like receptors and shifts T-cell differentiation to T(h)2, in response to anti-CD3 plus anti-CD28 mAb. Furthermore, we demonstrated that dopamine D2-like receptor antagonists, such as sulpiride and nemonapride, induced a significant DC-mediated T(h)2 differentiation, using mixed lymphocyte reaction between human Mo-DCs and allogeneic naive CD4(+) T cells. When dopamine release from Mo-DCs is inhibited by colchicines (a microtubule depolymerizer), T-cell differentiation shifts toward T(h)1. These findings identify DCs as a new source of dopamine, which functions as a T(h)2-polarizing factor in DC-naive T-cell interface.

An infant with asymptomatic hepatic granuloma probably caused by bacillus Calmette-Guérin (BCG) vaccination found incidentally at autopsy: a case report.

INTRODUCTION: Bacillus Calmette-Guérin (BCG) is an attenuated strain of Mycobacterium bovis. Usually, systemic complications due to BCG vaccination are quite rare. However, since BCG is a live vaccine, there is still a possibility that it may cause an infection. CASE PRESENTATION: Hepatic granuloma was found incidentally in an asymptomatic 5-month-old infant who was found dead in his bed. The probable cause of death was asphyxia due to milk aspiration into the lungs. The granuloma was composed of epithelioid histiocytes with frequent multinucleated Langhans-type giant cells and a small number of lymphocytes. CONCLUSION: The cause of the asymptomatic granuloma was not identified, but was considered likely due to BCG vaccination.

Evaluation of adjuvant activities using human antigen presenting cells in vitro.

BACKGROUND: Immunomodulators such as lipopolysaccharides (LPS) and forskolin change the nature of dendritic cells (DCs) to induce Th1 and Th2 cells, respectively, thereby designated Th1 or Th2 adjuvants. Our previous study showed that such activities can be qualitatively evaluated by expression patterns of Notch ligand isoforms, using human monocyte-derived DCs and some leukemic cell lines, such as THP-1 or KG-1. However, quantitative evaluation of the adjuvant activities was not fully established. METHODS: PMA-treated human monocytic cell line THP-1 was used as a target. Cells were stimulated with various adjuvants, and the intracellular levels of cAMP were determined. RESULTS: Th2 adjuvant forskolin was qualitatively evaluated by an increased expression of Delta1 in PMA-treated THP-1 cells, as reported in our previous study. In PMA-treated THP-1 cells, intracellular cAMP levels increased after stimulation with forskolin, in a dose-dependent manner. On the other hand, LPS, one of the known Th1 adjuvants, suppressed the increased cAMP level in a dose-dependent manner. CONCLUSIONS: Th2- and Th1-adjuvant activities can be quantitatively evaluated by using PMA-treated THP-1 cells and PMA-treated/forskolin-stimulated THP-1 cells, respectively.

Hypoxia induces upregulation of the deoxyribonuclease I gene in the human pancreatic cancer cell line QGP-1.

We have previously demonstrated that ischemia caused by acute myocardial infarction induces an abrupt increase of serum deoxyribonuclease I (DNase I) activity. In this study, we examined whether hypoxia can affect the levels of DNase I activity and/or its transcripts in vitro. We first exposed the human pancreatic cancer cell line QGP-1, which is the first documented DNase-I-producing cell line, to hypoxia (2% O2), and found that this induced a significant increase in both the activity and transcripts of DNase I. This response was mediated by increased transcription only from exon 1a of the two alternative transcription-initiating exons utilized simultaneously in the human DNase I gene (DNASE1); exposure of QGP-1 cells to hypoxia for 24 h resulted in a 15-fold increase of DNASE1 transcripts starting from exon 1a compared with the expression level under normoxic conditions. Promoter, electrophoretic mobility shift, and chromatin immunoprecipitation assays with QGP-1 cells exposed to hypoxia or normoxia showed that the region just upstream from exon 1a was involved in this response in a hypoxia-induced factor-1-independent, but at least in a Sp1 transcription factor-dependent manner possibly through enhanced binding of Sp1 protein to the promoter. These results indicate that DNASE1 expression is upregulated by hypoxia in the cells.

A case of iatrogenic cerebral infarction demonstrated by postmortem cerebral angiography.

A 37-year-old man with a meningioma compressing the right frontal lobe underwent preoperative embolization of the feeding vessels from the right meningeal artery. Although the first challenge was apparently successful, an excess amount of embolization agent was accidentally injected during the next procedure. X-ray monitoring demonstrated flow of contrast medium into the right internal carotid, anterior and middle cerebral arteries, and then the patient suddenly developed left hemiparesis, nausea, and deep coma. He died 48 days after the embolization treatment without improvement of the coma. A medicolegal autopsy was performed to determine whether malpractice had occurred during the embolization procedure. An internal examination demonstrated massive necrosis of the cerebral hemispheres and lobar pneumonia with abscess in the lungs. Due to the extensive brain necrosis, it was impossible to carry out ordinary macroscopic examination to identify the precise site of the craniocerebral vessel occlusion. Postmortem angiography was therefore performed, and this successfully revealed occlusion of the right internal carotid artery. In this case, postmortem angiography played a key role in identification of the intracranial vascular lesion that was responsible for the iatrogenic cerebral infarction.

[Full-field digital mammography with amorphous silicon-based flat- panel detector: physical imaging characteristics and signal detection].

The physical characteristics of a clinical amorphous silicon-based flat-panel imager for full-field digital mammography were investigated. Pre-sampled modulation transfer functions (MTF) were measured by using a slit method. Noise power spectra were determined for different input exposures by fast Fourier transform. The MTFs of full-field digital mammography systems showed significantly higher values than those of the computed radiography (CR) system. The full-field digital mammography system showed a lower noise level than that of the CR system under the same exposure conditions. Contrast detail analysis has been performed to compare the detectability of the full-field digital mammography system with that of the screen-film (Min-R 2000/Min-R 2000) system. The average contrast-detail curves of digital and film images were obtained from the results of observation. Image quality figures (IQF) were also calculated from the individual observer performance tests. The results indicated that the digital contrast-detail curves and IQF, on average, are superior to those of the screen-film system.