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Die Autorin schreibt von ihren Erfahrungen mit Selbstvertretungsstrukturen als Mitglied des Stadtschüler*innenrats der Stadt Leipzig und als Landesdelegierte für öffentliche Schulen. Dabei geht sie auf die Chancen und Grenzen einer solchen Mitbestimmungsstruktur ein. Sie beschreibt die Schwierigkeiten der Umsetzung und des Gehört Werdens in einem adultistisch geprägten Schulsystem und der Möglichkeit des Protestierens im öffentlichen Raum. (DIPF/Orig.)

ZusammenfassungDer pH-Wert des gesunden Menschen ist immens wichtig. Schon geringe Abweichungen führen zu massiven Störungen im Stoffwechsel, die unter Umständen lebensbedrohlich sind. Für den korrekten Ablauf biologischer Funktionen ist es wichtig, ein konstantes Verhältnis zwischen Säuren und Basen aufrechtzuerhalten. Ändert sich die Säurekonzentration, so hat das massive Auswirkungen auf die Aktivität von Enzymen oder die Struktur von Zellmembranen. Das Risiko für eine Schmerzentstehung ist insbesondere dann gegeben, wenn eine ernährungsbedingte Säurebelastung mit einer erhöhten Säureproduktion im Stoffwechsel zusammenkommt. Insgesamt gesehen belegen die Ergebnisse verschiedenster Untersuchungen die Bedeutung eines ausgeglichenen Säure-Basen-Haushalts auch bei Problemen im Gelenkbereich. Die Behebung einer alimentären Azidose durch ausreichende Basenzufuhr sollte Teil einer erfolgreichen Behandlung von Gelenkproblemen sein.

Background Atopic dermatitis (AD) is the most common cause of eczema. The skin condition affects millions of people worldwide. Severe cases of AD demand systemic treatment, but most AD cases rely on local therapy with topical corticosteroids, emollients, and moisturizing agents to alleviate eczema. Commonly, derma-cosmetics with a pH around 5.5 are used to treat eczematous lesions (EL). However, evidence is currently amassing that the use of mildly alkaline topical creams is beneficial for AD-related eczema treatment because of its effect on the inflammation in the skin. Aims To test an alkaline two-phase care concept for the treatment of eczema. Patients/methods An open-label study of 25 patients with eczema associated with mild AD. Patients were treated with Alkaline Build Up Caring Cream INTENSIVE and Alkaline Build Up Caring Cream PLUS+ (both Siriderma® ) for eight weeks. Dermatological, biochemical, and questionnaire-based examinations were conducted prior to the trial and after its completion. Results Topical administration of slightly alkaline creams led to small and statistically insignificant increases of skin pH. Clinical examination at the end of the observation period revealed a significant decrease of total eczematous-affected skin area, a significant decrease in average severity scores of EL, and significant improvements in patient-reported outcome parameters. Blood tests did not reveal any significant changes, except for small but significant increases in IL-8 and monocytes. Conclusion Mildly alkaline topical creams seem to provide soothing effects on eczema-related skin inflammation and thus might contribute to treatment of local symptoms of eczema in patients with mild AD.

ZusammenfassungMagnesiummangel verursacht neben zahlreichen weiteren Symptomen über die Steigerung von Gefäßtonus und Gefäßreaktivität einen Blutdruckanstieg. Eine optimale Magnesiumversorgung kann zur Prävention kardiovaskulärer Erkrankungen beitragen. In einer Untersuchung an älteren Hypertonikern bewirkte eine Therapie mit täglich 400 mg Magnesiumcitrat neben der Blutdrucksenkung eine signifikante Verbesserung des Vitamin-D-Status.

Magnesium (Mg) supplementation was shown to improve metabolic syndrome (MetS) parameters in hypomagnesemic patients. The current study evaluated the role of Mg in normomagnesemic individuals with MetS. Patients were randomly assigned to 400 mg Mg as Mg citrate or placebo daily for 12 weeks. Blood pressure (BP), HbA1c, plasma concentrations of glucose, Mg and Ca, blood-ionized Mg, serum concentrations of cholesterol, triglycerides, vitamin D, creatinine, interleukin-6, and C-reactive protein were measured at baseline and after 12 weeks. Data were obtained from n = 13 in the Mg supplemented and n = 11 in the placebo group. Mg supplementation led to a significant increase in plasma Mg concentration (0.78 ± 0.07 mmol/L to 0.83 ± 0.07 mmol/L) and a decrease in systolic and diastolic BP (baseline: 145 ± 10/85 ± 3 mmHg; 12 weeks: 121 ± 5/79 ± 3 mmHg). HbA1c decreased significantly in the Mg group (6.43 ± 0.64% to 6.15 ± 0.55%), and the difference in change between placebo and Mg group was significant. Serum vitamin D levels significantly increased only in the Mg group. In normomagnesemic individuals with MetS, oral Mg citrate supplementation reduced HbA1c and BP.

Magnesiummangel ist ein wichtiger Risikofaktor fur verschiedene Krankheiten. Die Mechanismen der Magnesiumhomoostase wurden in den letzten Jahren aufgeklart. Ein Magnesiummangel in der Nahrung fuhrt nicht zu schnellen Mangelsymptomen, da die Knochen die extrazellulare Magnesiumkonzentration puffern. Die Magnesiumkonzentration im Serum nimmt erst nach Erschopfung des Skelettspeichers ab. Eine reduzierte Serummagnesiumkonzentration (

Volume 11, no. 5, e02243-20, 2020, [https://doi.org/10.1128/mBio.02243-20][1]. The affiliation for Dr. Paniskaki was shown wrongly. The affiliation should appear as shown above. The article has been updated online. [1]: /lookup/doi/10.1128/mBio.02243-20

Cytotoxic T cells are responsible for the elimination of infected cells and are key players in the control of viruses. CD8+ T cells with an effector phenotype express cytotoxic molecules and are able to perform target cell killing. COVID-19 patients with a mild disease course were analyzed for the differentiation status and cytotoxic profile of CD8+ T cells. SARS-CoV-2 infection induced a vigorous cytotoxic CD8+ T cell response. However, this cytotoxic profile of T cells was not detected in COVID-19 patients over the age of 80 years. Thus, the absence of a cytotoxic response in elderly patients might be a possible reason for the more frequent severity of COVID-19 in this age group than in younger patients., Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection induces a T cell response that most likely contributes to virus control in COVID-19 patients but may also induce immunopathology. Until now, the cytotoxic T cell response has not been very well characterized in COVID-19 patients. Here, we analyzed the differentiation and cytotoxic profile of T cells in 30 cases of mild COVID-19 during acute infection. SARS-CoV-2 infection induced a cytotoxic response of CD8+ T cells, but not CD4+ T cells, characterized by the simultaneous production of granzyme A and B as well as perforin within different effector CD8+ T cell subsets. PD-1-expressing CD8+ T cells also produced cytotoxic molecules during acute infection, indicating that they were not functionally exhausted. However, in COVID-19 patients over the age of 80 years, the cytotoxic T cell potential was diminished, especially in effector memory and terminally differentiated effector CD8+ cells, showing that elderly patients have impaired cellular immunity against SARS-CoV-2. Our data provide valuable information about T cell responses in COVID-19 patients that may also have important implications for vaccine development.

Metabolism is controlled by macro- and micronutrients. Protein-rich diets should lead to latent acidosis at tissue level with further negative implications. Food supplements with alkaline salts are available and popular pretending to prevent these changes. Within a randomised double-blind placebo-controlled trial we tested the hypotheses that (1) a 4-week protein-rich diet induces a latent tissue acidosis and (2) an alkaline supplement can compensate this. Acid–base balance and important metabolic parameters were determined before and after 4 weeks of supplementation by peripheral blood samples, indirect calorimetry and muscle microdialysis before and after a protein-rich test meal. Fourty volunteers were randomised 1:1 to either verum or placebo supplements. Protein-rich diet by itself did not significantly affect acid–base balance. Alkaline supplementation increased plasma bicarbonate concentration without changing pH. Postprandial increases in serum glucose and insulin tended to be lower for verum vs. placebo. Resting and postprandial energy metabolism, and carbohydrate and fat oxidation did not differ significantly before and after supplementation in both groups. In muscle, postprandial glucose uptake and aerobic glucose oxidation were significantly higher for verum. In addition, verum significantly increased serum magnesium concentrations. Four weeks of protein-rich diet did not significantly influence acid–base balance. However, alkaline supplementation improved systemic and tissue acid–base parameters and oxidative glucose metabolism.

SARS-CoV-2 infection induces a T cell response that most likely contributes to virus control in COVID-19 patients, but may also induce immunopathology. Until now, the cytotoxic T cell response has not been very well characterized in COVID-19 patients.Here, we analyzed the differentiation and cytotoxic profile of T cells in 30 cases of mild COVID-19 during acute infection. SARS-CoV-2 infection induced a cytotoxic response of CD8+ T cells, but not CD4+ T cells, characterized by the simultaneous production of granzyme A and B, as well as perforin within different effector CD8+ T cell subsets. PD-1 expressing CD8+ T cells also produced cytotoxic molecules during acute infection indicating that they were not functionally exhausted. However, in COVID-19 patients over the age of 80 years the cytotoxic T cell potential was diminished, especially in effector memory and terminally differentiated effector CD8+ cells, showing that elderly patients have impaired cellular immunity against SARS-CoV-2.Our data provides valuable information about T cell responses in COVID-19 patients that may also have important implications for vaccine development.ImportanceCytotoxic T cells are responsible for the elimination of infected cells and are key players for the control of viruses. CD8+ T cells with an effector phenotype express cytotoxic molecules and are able to perform target cell killing. COVID-19 patients with a mild disease course were analyzed for the differentiation status and cytotoxic profile of CD8+ T cells. SARS-CoV-2 infection induced a vigorous cytotoxic CD8+ T cell response. However, this cytotoxic profile of T cells was not detected in COVID-19 patients over the age of 80 years. Thus, the absence of a cytotoxic response in elderly patients might be a possible reason for the more frequent severity of COVID-19 in this age group in comparison to younger patients.

Low magnesium (Mg) levels are linked to many diseases. Studies suggest that organic salts of Mg are more readily bioavailable than its oxide or inorganic salts used for supplements production. Unfortunately, the plethora of variables in the previous study designs complicates the making of any clear and reliable conclusions.14 healthy males were supplemented for five days with 400 mg Mg to saturate Mg pools before intake of the test products. Bioavailability of 400 mg Mg from Mg citrate (MgC) and Mg oxide (MgO) after single-dose administration was assessed by measuring renal Mg excretion in 24-h urine and blood plasma [Mg] at time points 0, 2, 4, 8, and 24 h.Single-dose MgC supplementation led to a significant (P 0.05) increase in 24 h urinary Mg excretion, but this was not significant following MgO. Plasma [Mg] was also significantly higher for MgC than for MgO at 4 h (P 0.05) and 8 h (P 0.05). Compared with baseline levels, MgC supplementation showed a significant increase in plasma [Mg] at all time points, in contrast to MgO.MgC shows higher bioavailability compared with MgO. Furthermore, urinary Mg excretion should be determined as the primary endpoint of Mg bioavailability studies.

Combination immunotherapy (CIT) is currently applied as a treatment for different cancers and is proposed as a cure strategy for chronic viral infections. Whether such therapies are efficient during an acute infection remains elusive. To address this, inhibitory receptors were blocked and regulatory T cells depleted in acutely Friend retrovirus-infected mice. CIT resulted in a dramatic expansion of cytotoxic CD4+ and CD8+ T cells and a subsequent reduction in viral loads. Despite limited viral replication, mice developed fatal immunopathology after CIT. The pathology was most severe in the gastrointestinal tract and was mediated by granzyme B producing CD4+ and CD8+ T cells. A similar post-CIT pathology during acute Influenza virus infection of mice was observed, which could be prevented by vaccination. Melanoma patients who developed immune-related adverse events under immune checkpoint CIT also presented with expanded granzyme-expressing CD4+ and CD8+ T cell populations. Our data suggest that acute infections may induce immunopathology in patients treated with CIT, and that effective measures for infection prevention should be applied., Author summary Combination immunotherapy (CIT) directed against checkpoint mechanisms has been approved for the therapy of cancers and is proposed for the treatment of chronic infections. In cancer therapy patients often develop severe immunopathology under CIT. Here we show that acute viral infections (Friend retrovirus and Influenza virus) posed a significant threat during CIT in mice. The strong activation of cytotoxic T cells after an acute viral infection seemed to lack couterregulation during CIT, which resulted in lethal immunopathology. In case of an Influenza virus infection this could be prevented by vaccination prior to CIT. The expansion of CD4+ and CD8+ T cells expressing cytotoxic molecules were also observed in melanoma patients treated with two checkpoint blockers. Thus, these patients might also be at risk of developing severe immunopathology during an otherwise harmless acute viral infection. This should to be taken into account when cancer patients are undergoing CIT.

ZUSAMMENFASSUNGSeit einigen Jahren wird die äußerliche Anwendung von Magnesium zur Behandlung von Magnesiummangel und Muskelkrämpfen beworben. Seriöse Studien konnten jedoch keine transdermale Aufnahme des essenziellen Mineralstoffs aus magnesiumreichem Badewasser oder Lotionen nachweisen. Demgegenüber ist die orale Magnesiumsupplementierung in Therapie und Prophylaxe wissenschaftlich gesichert und anerkannt. Der rechtliche Status transdermaler Magnesiumprodukte ist ungeklärt.

The importance of magnesium and the positive effects of magnesium substitution in various diseases are extensively documented [ 1 , 2 ]. Magnesium compounds are widely used as medicinal and dietary supplements. The effectiveness of oral magnesium substitution for the treatment of magnesium deficiency is beyond controversy. However, the scientific seriousness of oral magnesium substitution has become questioned for several years through intensive marketing of magnesium-containing sprays for topical application. In both, specialist and lay press and on the internet, there are increasing numbers of articles claiming the effectiveness and superiority of magnesium oil over an oral magnesium intake. Magnesium oil is no real oil but a concentrated magnesium chloride solution which is sprayed on the skin. The transdermal absorption of magnesium in comparison to oral supplementation is presented as being more effective on the one hand due to nearly 100% absorption and on the other hand as it is associated with fewer side effects because of bypassing the intestinal tract. For proving this, various publications are mentioned.

Cytotoxic CD8+ T lymphocytes (CTL) efficiently control acute virus infections but can become exhausted when a chronic infection develops. The checkpoint receptor PD-1 suppresses the functionality of virus-specific CD8+ T cells during chronic infection. However, the role of the PD-L1/PD-1 pathway during the acute phase of infections has not been well characterized. In the current study the effects of PD-1 or PD-L1 deficiency on the CD8+ T cell response against Friend retroviral (FV) infection of knockout mice was analyzed during acute infection. We observed an enhanced proliferation, functional maturation, and reduced apoptosis of effector CD8+ T cells in the absence of PD-1 or PD-L1. The knockout of PD-L1 had a stronger effect on the functionality of CD8+ T cells than that of PD-1. Augmented CTL responses were associated with an improved control of FV replication. The strong phenotype of FV-infected PD-L1 knockout mice was independent of the interaction with CD80 as an additional receptor for PD-L1. Furthermore, we performed a detailed analysis of the production of different granzymes in virus-specific CD8+ T cells and observed that especially the simultaneous production of multiple granzymes in individual T cells (multifunctionality) was under the control of the PD-1/PD-L1 pathway. The findings from this study allow for a better understanding of the development of antiviral cytotoxic immunity during acute viral infections. CA Zelinskyy

Background: Intermittent fasting (IF) combined with exercise has been suggested to enhance weight loss. However, both procedures might negatively influence acid&ndash, base status. The aim of this study was to determine the combined effects of IF, exercise training and alkaline supplementation in overweight subjects on body composition and running performance. Methods: 80 overweight subjects of age 45.5 &plusmn, 7.8 years were assigned to IF or non-intermittent fasting (nIF). Furthermore, subjects were randomly assigned to take either an alkaline supplement (IF-v, nIF-v) or a placebo (IF-p, nIF-p) twice a day. All subjects performed a personalized endurance exercise program (3&ndash, 4 times/week for 12 weeks). Body weight, body composition, running performance and acid&ndash, base parameters were determined before (pre) and after the 12-week program (post). Results: 68 participants completed the study. There was a significant effect on body weight loss, body fat loss, visceral fat loss and running performance enhancement in all groups (p &lt, 0.01) for pre and post measurements. Body weight decreased in all groups (IF-p: &minus, 5.80 &plusmn, 0.77 kg and nIF-p: &minus, 3.40 &plusmn, 0.58 kg, IF-v: &minus, 8.28 &plusmn, 0.75 kg and nIF-v: &minus, 5.59 &plusmn, 0.87 kg). In both dietary strategies, weight loss was significantly further enhanced by alkaline supplementation. The increase in running velocity was significantly higher in IF combined with alkaline supplementation (IF-v 1.73 &plusmn, 0.23 km/h and IF-p 0.97 &plusmn, 0.20 km/h). In addition, alkaline supplementation increased plasma HCO3&minus, concentration and urinary pH. Conclusion: Exercise training in combination with IF and alkaline supplementation is an effective strategy to reduce body weight and improve running performance in a 12-week intervention.

Magnesium research has boomed within the last 20 years. The real breakthrough came at the start of the new millennium with the discovery of a plethora of possible Mg homeostatic factors that, in particular, included putative Mg2+ transporters. Until that point, Mg research was limited to biochemical and physiological work, as no target molecular entities were known that could be used to explore the molecular biology of Mg homeostasis at the level of the cell, tissue, organ, or organism and to translate such knowledge into the field of clinical medicine and pharmacology. Because of the aforementioned, Mg2+ and Mg homeostasis, both of which had been heavily marginalized within the biomedical field in the twentieth century, have become overnight a focal point of many studies ranging from primary biomedical research to translational medicine.

Background: Myeloid-derived suppressor cells (MDSCs) can suppress T cell responses in several different diseases. Previously these suppressive cells were observed to expand in HIV patients and in a mouse retrovirus model, yet their suppressive effect on virus-specific CD8+ T cells in vitro and in vivo has not been characterized thus far. Results: We used the Friend retrovirus (FV) model to demonstrate that MDSCs expand and become activated during the late phase of acute FV infection. Only the subpopulation of granulocytic MDSCs (gMDSCs) but not monocytic MDSC suppressed virus-specific CD8+ T cell proliferation and function in vitro. gMDSCs expressed arginase 1, high levels of the inhibitory ligand PD-L1 and the ATP dephosphorylating enzyme CD39 on the cell surface upon infection. All three molecules were involved in the suppressive effect of the gMDSCs in vitro. MDSC depletion experiments in FV-infected mice revealed that they restrict virus-specific CD8+ T cell responses and thus affect the immune control of chronic retroviruses in vivo. Conclusions: Our study demonstrates that MDSCs become activated and expand during the acute phase of retrovirus infection. Their suppressive activity on virus-specific CD8+ T cells may contribute to T cell dysfunction and the development of chronic infection. CA Zelinskyy

Cytotoxic CD8+ T Lymphocytes (CTL) efficiently control acute virus infections but can become exhausted when a chronic infection develops. Signaling of the inhibitory receptor PD-1 is an important mechanism for the development of virus-specific CD8+ T cell dysfunction. However, it has recently been shown that during the initial phase of infection virus-specific CD8+ T cells express high levels of PD-1, but are fully competent in producing cytokines and killing virus-infected target cells. To better understand the role of the PD-1 signaling pathway in CD8+ T cell cytotoxicity during acute viral infections we analyzed the expression of the ligand on retrovirus-infected cells targeted by CTLs. We observed increased levels of PD-L1 expression after infection of cells with the murine Friend retrovirus (FV) or with HIV. In FV infected mice, virus-specific CTLs efficiently eliminated infected target cells that expressed low levels of PD-L1 or that were deficient for PD-L1 but the population of PD-L1high cells escaped elimination and formed a reservoir for chronic FV replication. Infected cells with high PD-L1 expression mediated a negative feedback on CD8+ T cells and inhibited their expansion and cytotoxic functions. These findings provide evidence for a novel immune escape mechanism during acute retroviral infection based on PD-L1 expression levels on virus infected target cells., Author Summary Virus-specific cytotoxic T cells can eliminate infected cells during acute viral infections, but in chronic infections these cells often become dysfunctional or “exhausted.” The inhibitory receptor PD-1 is involved in the suppression of cytotoxic T cell responses in chronic infections. However, during many acute viral infections cytotoxic T cells up-regulate the PD-1 receptor but initially remain competent in killing virus infected target cells. Here we show that the ligand for PD-1, called PD-L1, can be induced on retrovirus infected cells and that the cells with the highest expression of PD-L1 escaped from cytotoxic T cell killing. Thus, PD-L1high infected target cells accumulated during the course of infection, formed the reservoir of virus persistence, and subsequently mediated a negative feedback on cytotoxic T cells via the PD-1 receptor that ultimately resulted in functional exhaustion of these cells. The current results provide evidence for a novel escape mechanism of viruses from cytotoxic T cell responses and may explain how viral reservoirs are established during chronic infections.

Triatomines inhibit the clotting of ingested blood in the stomach (anterior midgut). After verifying this phenomenon in Panstrongylus megistus using coagulation assays, a full-length cDNA encoding a Kazal-like inhibitor was amplified by PCR. The open reading frame encodes a putative precursor protein of 412 amino acid residues, which was named PmStKaz and contains seven Kazal-like domains forming four Kazal-type inhibitors. A single domain inhibitor and three double-domain inhibitors possess sequence identities of up to 91% to the respective domains of Kazal-type inhibitors from other triatomines. The gene is expressed in the stomach (anterior midgut) but not in the small intestine (posterior midgut), salivary glands or haemocytes. After hydrophobic interaction chromatography of the stomach contents, four fractions (numbers 1–4) inhibited the activity of trypsin, fraction 2 that of subtilisin A, fractions 1, 3 and 4 that of plasmin, and fractions 3 and 4 that of thrombin. After ion exchange chromatography, MALDI-TOF-MS analysis of the intact proteins in fractions 3 and 4 showed diverse masses correlating to PmStKaz IV–V and PmStKaz II–III, respectively. Both proteins seem to be present in several isoforms with variant amino- and carboxy-terminal ends. In reverse zymography of the proteins of the stomach contents after separation by isoelectric focusing and non-reducing SDS-PAGE, much higher concentrations of isoforms of PmStKaz II–III and IV–V were evident than of PmStKaz I and VI–VII.

Advancing knowledge regarding the cellular mechanisms of intestinal inflammation has led to a better understanding of the disease pathology in patients with inflammatory bowel disease (IBD) including Crohn's disease and ulcerative colitis. It has become clear from numerous studies that enteric bacteria are a critical component in the development and prevention/treatment of chronic intestinal inflammation. An emerging new paradigm suggests that changes in the homeostasis of bacteria- and host-derived signal transduction at the intestinal epithelial cell (IEC) level may lead to a break in barrier function and the development of adaptive immune disturbances. The functional loss of anti-inflammatory host-derived signals in the gut including the immunosuppressive cytokines Interleukin 10 (IL-10) and transforming growth factor (TGF)-beta are of high relevance to the pathogenesis of IBD. The development of analytical tools including two-dimensional (2D) high-resolution protein separation techniques and peptide mass fingerprinting via high-sensitivity mass-spectrometers (MS) allows the quantitative assessment of protein expression changes in disease-relevant cell types. By using these advanced methods, the characterization of the epithelial cell proteome from murine models of experimental colitis and human IBD patients identified novel disease-related mechanisms with respect to the regulation of the glucose-regulated endoplasmic reticulum stress response protein 78 (grp-78). In conclusion, the identification and functional analysis of differentially expressed proteins in purified intestinal target cell types will help to add important insights to the understanding of the molecular pathogenesis of these immune-mediated chronic intestinal disorders.

The interaction of nonpathogenic enteric bacteria with intestinal epithelial cells (IEC) in the absence of host-derived Interleukin 10 (IL-10) may contribute to the development of chronic inflammation. Functional proteome analysis of primary IEC from Enterococcus faecalis-monoassociated WT and IL-10-/- mice as well as IL-10 receptor reconstituted IEC revealed expression changes of proteins that are involved in endoplasmic reticulum stress, energy metabolism, and apoptosis, suggesting a protective role for IL-10 at the epithelial cell level.

The loss of intestinal epithelial cell (IEC) function is a critical component in the initiation and perpetuation of chronic intestinal inflammation in the genetically susceptible host. We applied proteome analysis (PA) to characterize changes in the protein expression profile of primary IEC from patients with Crohn's disease (CD) and ulcerative colitis (UC). Surgical specimens from 18 patients with active CD (N = 6), UC (N = 6), and colonic cancer (N = 6) were used to purify primary IEC from ileal and colonic tissues. Changes in protein expression were identified using 2D-gel electrophoreses (2D SDS-PAGE) and peptide mass fingerprinting via MALDI-TOF mass spectrometry (MS) as well as Western blot analysis. PA of primary IEC from inflamed ileal tissue of CD patients and colonic tissue of UC patients identified 21 protein spots with at least 2-fold changes in steady-state expression levels compared to the noninflamed tissue of control patients. Statistical significance was achieved for 9 proteins including the Rho-GDP dissociation inhibitor alpha that was up-regulated in CD and UC patients. Additionally, 40 proteins with significantly altered expression levels were identified in IEC from inflamed compared to noninflamed tissue regions of single UC (N = 2) patients. The most significant change was detected for programmed cell death protein 8 (7.4-fold increase) and annexin 2A (7.7-fold increase). PA in primary IEC from IBD patients revealed significant expression changes of proteins that are associated with signal transduction, stress response as well as energy metabolism. The induction of Rho GDI alpha expression may be associated with the destruction of IEC homeostasis under condition of chronic intestinal inflammation.

The authors would like to correct panel H in Fig 3 to show the correct MFI values of PD-L1 expression on human CD4+ T cells. The error occurred during preparation of the figure for manuscript revision. The percentages of infected CD4 cells expressing PD-L1 were accidentally duplicated from panel I in Fig 3. Please see the corrected version of Fig 3 here. Fig 3 PD-L1 expression on cells infected in vitro with FV or HIV.

Background Iron replacement therapy is a common treatment in patients with anaemia and Crohn9s disease, but oral iron supplements are less tolerated. The pathogenesis of Crohn9s disease is attributed to intestinal bacteria and environmental factors that trigger disease in a genetically predisposed host. The aim of this study was to characterise the interrelationship between luminal iron sulfate, systemic iron, the gut microbiota and the development of chronic ileitis in a murine model of Crohn9s disease. Methods Wild type (WT) and heterozygous TNF ΔARE/WT mice were fed with an iron sulfate containing or iron sulfate free diet in combination with intraperitoneal control injections or iron injections for 11 weeks. Results TNF ΔARE/WT mice develop severe inflammation of the distal ileum but remained completely healthy when transferred to an iron sulfate free diet, even if iron was systemically repleted. Absence of luminal iron sulfate reduced cellular markers of endoplasmic reticulum (ER) stress responses and pro-apoptotic mechanisms in the ileal epithelium. Phenotype or reactivity of major effector intraepithelial CD8αβ + T cells were not altered in the absence of luminal iron. Interestingly, ER stress mechanisms sensitised the small intestinal epithelial cell (IEC) line Mode-K to cytotoxic function of effector T cells from TNF ∆ARE/WT mice. Pyrosequencing of 16S rRNA tags of the caecal microbiota revealed that depletion of luminal iron sulfate induced significant compositional alterations, while total microbial diversity (Shannon9s diversity index) and number of total operational taxonomic units were not affected. Conclusion This study showed that an iron sulfate free diet in combination with systemic iron repletion prevents the development of chronic ileitis in a murine model of Crohn9s disease. Luminal iron may directly affect IEC function or generate a pathological milieu in the intestine that triggers epithelial cell stress-associated apoptosis through changes in microbial homeostasis. These results suggest that oral replacement therapy with iron sulfate may trigger inflammatory processes associated with progression of Crohn9s disease-like ileitis.

Cytotoxic CD8+ T cells control acute viremia in many viral infections. However, most viruses that establish chronic infections evade destruction by CD8+ T cells, and regulatory T cells (Treg) are thought to be involved in this immune evasion. We have infected transgenic mice, in which Treg can be selectively depleted, with Friend retrovirus (FV) to investigate the influence of Treg on pathogen-specific CD8+ T-cell responses in vivo. We observed that Treg expansion during acute infection was locally defined to organs with high viral loads and massive activation of virus-specific effector CD8+ T cells. Experimental ablation of Treg resulted in a significant increase of peak cytotoxic CD8+ T-cell responses against FV. In addition, it prevented the development of functional exhaustion of CD8+ T cells and significantly reduced FV loads in lymphatic organs. Surprisingly, despite the massive virus-specific CD8+ T-cell response after temporary Treg depletion, no evidence of immunopathology was found. These results demonstrate the important role of Treg in controlling acute retrovirus-specific CD8+ T-cell responses, and suggest that temporary manipulation of Treg might be a possible therapeutic approach in chronic infectious diseases.

After more than 30 years of research a HIV vaccine is still not at hand. DNA vectors expressing viral antigens are very safe vaccines, but so far they have not been efficient enough to induced broad protective immunity against retroviruses. One strategy to enhance the efficiency of DNA vaccines is to augment effector T-cell priming against viral components by manipulating regulatory T-cell functions (Treg). Glucocorticoid-induced tumor necrosis factor receptor (GITR) is a molecule that is constitutively expressed on CD4(+) Treg cells, and antibodies or natural ligands binding this molecule can impair Treg cell suppression. Here we demonstrate using the retroviral Friend virus (FV) mouse model, that co-immunization of FV antigens along with GITR-ligand (GITRL) encoding plasmids protected mice efficiently against a FV challenge. On the other hand, treatment of DNA-vaccinated mice with alpha-GITR antibody did not improve vaccine-induced protection at all. Thus, for an effective priming of immunity against FV, GITRL and viral antigens might have to be expressed within the same local environment. The data suggest that limitations in DNA vaccination can be overcome by co-expressing co-stimulatory molecules that potentially manipulate the function of Treg cells during priming of anti-retroviral immunity.

Cytotoxic T cells (CTL) play a central role in the control of viral infections. Their antiviral activity can be mediated by at least two cytotoxic pathways, namely, the granule exocytosis pathway, involving perforin and granzymes, and the Fas-FasL pathway. However, the viral factor(s) that influences the selection of one or the other pathway for pathogen control is elusive. Here we investigate the role of viral replication levels in the induction and activation of CTL, including their effector potential, during acute Friend murine leukemia virus (F-MuLV) infection. F-MuLV inoculation results in a low-level infection of adult C57BL/6 mice that is enhanced about 500-fold upon coinfection with the spleen focus-forming virus (SFFV). Both the low- and high-level F-MuLV infections generated CD8+effector T cells that were essential for the control of viral replication. However, the low-level infection induced CD8+T cells expressing solely FasL but not the cytotoxic molecules granzymes A and B, whereas the high-level infection resulted in induction of CD8+effector T cells secreting molecules of the granule exocytosis pathway. By using knockout mouse strains deficient in one or the other cytotoxic pathway, we found that low-level viral replication was controlled by CTL that expressed FasL but control of high-level viral replication required perforin and granzymes. Additional studies, in which F-MuLV replication was enhanced experimentally in the absence of SFFV coinfection, supported the notion that only the replication level of F-MuLV was the critical factor that determined the differential expression of cytotoxic molecules by CD8+T cells and the pathway of CTL cytotoxicity.

activity, but also MMP-9 activity in DSS-treated mice. Chymase activity was significantly lower in the NK3201-treated group than in the placebo-treated group. MMP-9 level was also significantly lower in the NK3201-treated group than in the placebo-treated group. In NSAID-induced small intestinal enteritis, MMP-9 level was significantly increased to 5.6 and 9.2 times of control intestinal. Chymase inhibitor significantly decreased to 13.9% the ulcer index compared with placebo. Conclusion: These findings suggest that chymase plays an important role in the development of gut inflammation via MMP-9 activation.