[The unusual mimicker of a polymyositis]. / Der außergewöhnliche Nachahmer einer Polymyositis.

This article describes a hantavirus-associated pronounced myositis as a rare differential diagnosis to polymyositis. The literature on the pathogenesis of hantavirus disease discusses less a direct viral cytopathology but more a secondary immune dysregulation with induction of a capillary leak. This article describes for the first time a case of successful treatment of protracted hantavirus myositis using high-dose glucocorticoids and cyclophosphamide, followed by ciclosporin and MTX.

Evaluation of choroidal substructure perfusion in patients affected by systemic sclerosis: an optical coherence tomography angiography study.

Objective: Vasculopathy in systemic sclerosis (SSc) is characterized by the obliteration of arterioles and a reduced capillary density in various tissues. In SSc, atrophic alterations of the choroid have been suggested based on morphological data acquired by optical coherence tomography (OCT). In this study, we aimed to assess the choroid in eyes of patients with SSc from a microcirculatory, dynamic point of view by adding optical coherence tomography angiography (OCTA) to the diagnostic spectrum.Method: SSc patients were enrolled, and age- and gender-matched healthy subjects were used as controls. In addition to basic ophthalmological and rheumatological examinations, individuals underwent enhanced-depth imaging OCT and OCTA. Subfoveal thicknesses of the choroid as well as all three choroidal vascular sublayers were measured and submacular perfusion values were evaluated.Results: In total, 12 patients with SSc and 12 matched controls were included. The median age of participants was 64 years. Submacular perfusion was significantly lower in the choriocapillaris (Δ = 0.72%; p = 0.045), Sattler's layer (Δ = 2.87%; p = 0.001), and Haller's layer (Δ = 2.69%; p = 0.018) of SSc patients compared to controls. Subfoveal thicknesses of Sattler's layer (Δ = 15 µm; p = 0.026) and Haller's layer (Δ = 41 µm; p = 0.045) were also significantly smaller in the SSc group.Conclusion: Choroidal microcirculation is impaired in SSc, even in patients without ophthalmological symptoms. Choroidal OCT and OCTA may offer additional biomarkers for SSc activity.

[Regulatory T cells and rheumatic diseases]. / Regulatorische T-Zellen und rheumatische Erkrankungen.

BACKGROUND: Regulatory T cells (Treg) are crucial for the maintenance of immunological peripheral tolerance by controlling the activation and expansion of autoreactive cells; therefore, they make a decisive contribution to the prevention and control of autoimmune diseases. OBJECTIVES: The aims of this article are to summarize the history and role of Treg in science and medicine, to provide a brief introduction to the development and function, to explain how failures in Treg biology contribute to the development of autoimmune disease, to explain their specific role in particular rheumatic diseases and to provide an introduction to the therapeutic use of Treg in autoimmune diseases. METHODS: Relevant original literature and review articles were analyzed and the results are summarized in this article. RESULTS: Disorders in Treg biology can contribute to the development of rheumatic diseases in various ways. In addition, their capability to suppress autoimmunity renders Treg an attractive target for the treatment of rheumatic diseases. CONCLUSIONS: The concept of Treg-mediated immunoregulation has evolved into an independent field of research in immunology and medicine. First translational approaches and clinical studies confirmed the therapeutic efficacy of Treg in the treatment of autoimmune syndromes.

CXCR3+CD4+ T cells are enriched in inflamed kidneys and urine and provide a new biomarker for acute nephritis flares in systemic lupus erythematosus patients.

OBJECTIVE: The high frequency of CD4+ T cells in interstitial infiltrates of patients with lupus nephritis suggests a contribution of these cells to local pathogenesis. The aim of this study was to examine the role of CXCR3 and the chemokine CXCL10 in recruiting these cells into the kidney and to determine whether the infiltrating T cells could be monitored in the urine to provide a reliable biomarker for acute lupus nephritis. METHODS: The frequencies of CD3+ T cells, CXCR3+ cells, and CXCL10+ cells were determined by immunohistochemical and immunofluorescence analyses of kidney sections from 18 patients with lupus nephritis. The frequency of CXCR3+CD4+ T cells was determined by flow cytometry of peripheral blood and urine from 38 patients with systemic lupus erythematosus (SLE), and the values were compared with disease activity as determined by the Systemic Lupus Erythematosus Disease Activity Index. RESULTS: In renal biopsy tissues from patients with lupus nephritis, a mean of 63% of the infiltrating cells expressed CXCR3, approximately 60% of them were T cells, and the CXCR3+ cells colocalized with CXCL10-producing cells. In biopsy tissues from SLE patients with acute nephritis, approximately 50% of the urinary CD4+ T cells were CXCR3+, as compared with 22% in the peripheral blood, and the frequency of urinary CXCR3+CD4+ T cells correlated with disease activity. Moreover, the number of urinary CD4+ T cells reflected nephritis activity, and elevation above 800 CD4+ T cells per 100 ml of urine sharply delineated active from inactive nephritis. CONCLUSION: CXCR3+ T cells are recruited into the inflamed kidneys, are enriched in the urine, and are a valuable marker of nephritis activity in SLE. They also present a potential target for future therapies.

The highly attenuated vaccinia virus strain modified virus Ankara induces apoptosis in melanoma cells and allows bystander dendritic cells to generate a potent anti-tumoral immunity.

Vaccinia virus (VV) has been tested as oncolytic virus against malignant melanoma in clinical trials for more than 40 years. Until now, mainly strains comparable to viral strains used for smallpox vaccination have been probed for anti-tumoral therapy. We have shown recently that the wild-type strain Western Reserve (WR) can interfere with crucial functions of monocyte-derived dendritic cells (DCs). Our aim was to examine whether viral immune evasion mechanisms might be responsible for the ineffectiveness of WR-based vaccination strategies and whether the highly attenuated strain modified virus Ankara (MVA) differs from WR with respect to its possible immunostimulatory capacity after intratumoral injection. Using in vitro experiments, we compared the effect of both strains on melanoma cells and on local bystander DCs. We found that both VV-strains infected melanoma cells efficiently and caused disintegration of the actin cytoskeleton, as shown by fluorescence microscopy. In addition, both VV-strains caused apoptotic cell death in melanoma cells after infection. In contrast to MVA, WR underwent a complete viral replication cycle in melanoma cells. Bystander DCs were consecutively infected by newly generated WR virions and lost their capacity to induce allogeneic T cell proliferation. DCs in contact with MVA-infected melanoma cells retained their capacity to induce T cell proliferation. Immature DCs were capable of phagocytosing MVA-infected melanoma cells. Priming of autologous CD8(+) T cells by DCs that had phagocytosed MVA-infected, MelanA positive melanoma cells resulted in the induction of T cell clones specifically reactive against the model antigen MelanA as shown by enzyme-linked immunospot (ELISPOT) analysis. We conclude that the clinical trials with oncolytic wild-type VV failed probably because of suppression of bystander DCs and consecutive suppression of T cell-mediated anti-melanoma immunity. The attenuated VV-strain MVA facilitates the generation of tumour associated antigen (TAA)-specific T cell response as it is oncolytic for melanoma cells, but non-toxic for DC, and should be a promising candidate for intralesional metastatic melanoma therapy.

Effects of two Gbetagamma-binding proteins--N-terminally truncated phosducin and beta-adrenergic receptor kinase C terminus (betaARKct)--in heart failure.

Myocardial overexpression of the C-terminus of beta-adrenergic receptor kinase (betaARKct) has been shown to result in a positive inotropic effect or an improvement of survival in heart failure. However, it is not clear whether this beneficial effect is mainly because of dominant-negative inhibition of betaARK1, and a consecutive resensitization of beta-adrenergic receptors (betaAR), or rather due to inhibition of other Gbetagamma-mediated effects. In this study, we tested whether overexpression of N-terminally truncated phosducin (nt-del-phosducin), another Gbetagamma-binding protein that does not resensitize betaARs owing to simultaneous inhibition of GDP release from Galpha subunits, shows the same effects as betaARKct. Adenoviral gene transfer was used to express nt-del-phosducin and betaARKct in isolated ventricular cardiomyocytes and in myocardium of rabbits, which suffered from heart failure because of rapid ventricular pacing. BetaAR-stimulated cAMP formation was increased by betaARKct, but not by nt-del-phosducin, whereas both proteins inhibited Gbetagamma-mediated effects. Both transgenes also increased contractility of normal and failing isolated cardiomyocytes and improved contractility in rabbits with heart failure after gene transfer in vivo. In conclusion, overexpression of nt-del-phosducin enhances the contractility of cardiomyocytes to the same extent as betaARKct, suggesting that the effects of betaARKct might be owing to inhibition of Gbetagamma rather than to betaAR resensitization.

Viral vectors for dendritic cell-based immunotherapy.

Dendritic cells (DCs) constitute a specialised system of antigen-presenting cells with a high capacity to induce and to modulate the immune response against microbial, tumour and self-antigens. New techniques to generate large amounts of DCs together with the molecular identification of human tumour-associated antigens (TAA) have opened new ways for antigen-specific cancer immunotherapies. DCs loaded either with TAA-derived MHC class I-specific synthetic peptides or with whole tumour cell preparations have been used in numerous clinical trials evaluating the efficacy of DCs in patients with cancer. However, the disadvantages of DCs pulsed with synthetic peptides from TAA include the uncertainty regarding the longevity of antigen presentation, the restriction by the patient's haplotype and the relatively low number of known MHC class I and in particular of MHC class II helper cell-related epitopes. Whole tumour cell preparations are difficult to standardise, and they depend on the availability of tumour cells. Thus the utilisation of viral vectors genetically modified to express TAA for the ex vivo transduction of DCs is an attractive alternative to achieve a MHC I- and MHC II-restricted presentation of tumoural antigens. To induce protective anti-tumoural immune response an increasing number of modified viral vectors have been used to transduce DCs. Although high transduction efficacies were reported for several viruses, analysis of the interaction of viral vectors with DCs has revealed several viral mechanisms that interfere with main functions of DCs, dampening somewhat the initial optimism in the field of DC transduction. However, promising results with different vectors have been achieved. In this review we summarise available data and discuss advantages and drawbacks of currently available vectors.

Phosphorylation of phosducin and phosducin-like protein by G protein-coupled receptor kinase 2.

G protein-coupled receptor kinase 2 (GRK2) is able to phosphorylate a variety of agonist-occupied G protein-coupled receptors (GPCR) and plays an important role in GPCR modulation. However, recent studies suggest additional cellular functions for GRK2. Phosducin and phosducin-like protein (PhLP) are cytosolic proteins that bind Gbetagamma subunits and act as regulators of G-protein signaling. In this report, we identify phosducin and PhLP as novel GRK2 substrates. The phosphorylation of purified phosducin and PhLP by recombinant GRK2 proceeds rapidly and stoichiometrically (0.82 +/- 0.1 and 0.83 +/- 0.09 mol of P(i)/mol of protein, respectively). The phosphorylation reactions exhibit apparent K(m) values in the range of 40-100 nm, strongly suggesting that both proteins could be endogenous targets for GRK2 activity. Our data show that the site of phosducin phosphorylation by GRK2 is different and independent from that previously reported for the cAMP-dependent protein kinase. Analysis of GRK2 phosphorylation of a variety of deletion mutants of phosducin and PhLP indicates that the critical region for GRK2 phosphorylation is localized in the C-terminal domain of both phosducin and PhLP (between residues 204 and 245 and 195 and 218, respectively). This region is important for the interaction of these proteins with G beta gamma subunits. Phosphorylation of phosducin by GRK2 markedly reduces its G beta gamma binding ability, suggesting that GRK2 may modulate the activity of the phosducin protein family by disrupting this interaction. The identification of phosducin and PhLP as new substrates for GRK2 further expands the cellular roles of this kinase and suggests new mechanisms for modulating GPCR signal transduction.

Brain insulin and insulin receptors in aging and sporadic Alzheimer's disease.

The search for the causes of neurodegenerative disorders is a major theme in brain research. Acquired disturbances of several aspects of cellular metabolism appear pathologically important in sporadic Alzheimer's disease (SDAT). Among these brain glucose utilisation is reduced in the early stages of the disease and the regulatory enzymes important for glucose metabolism are reduced. In the brain, insulin, insulin-like growth factors and their receptors regulate glucose metabolism and promote neuronal growth. To detect changes in the functional activity of the brain insulin neuromodulatory system of SDAT patients, we determined the concentrations of insulin and c-peptide as well as insulin receptor binding and IGF-I receptor binding in several regions of postmortem brain cortex during aging and Alzheimer's disease. Additionally, we performed immunohistochemical staining with antibodies against insulin in neocortical brain areas in SDAT and controls. We show for the first time that insulin and c-peptide concentration in the brain are correlated and decrease with aging, as do brain insulin receptor densities. Weak insulin-immunoreactivity could be demonstrated histochemically in pyramidal neurons of controls, whereas in SDAT a stronger insulin-immunoreactivity was found. On a biochemical level, insulin and c-peptide levels were reduced compared to middle-aged controls, but were unchanged compared to age-matched controls. Brain insulin receptor densities in SDAT were decreased compared to middle-aged controls, but increased in comparison to age-matched controls. IGF-I receptor densities were unchanged in aging and in SDAT. Tyrosine kinase activity, a signal transduction mechanism common to both receptor systems, was reduced in SDAT in comparison to middle-aged and age-matched control groups. These data are consistent with a neurotrophic role of insulin in the human brain and a disturbance of insulin signal transduction in SDAT brain and favor the hypothesis that insulin dependent functions may be of pathogenetic relevance in sporadic SDAT.

The effects of selective and non-selective monoamine oxidase (MAO) inhibitors on conflict behavior in the rat.

Conflict behavior in rats was examined over the course of several weeks of chronic treatment with selective and non-selective monoamine oxidase inhibitors (MAOIs). In daily 10min sessions, rats were trained to drink from a tube which was occasionally electrified (0.5mA). Electrification was signalled by the presence of a tone. Within 3-4 weeks, control (i.e. non-drug) conflict behavior had stabilized (30-40 shocks and 8-12ml water/session) and drug testing began. Chronic administration (two injections/day for 8 weeks) with a non-selective (i.e. MAO-A and MAO-B inhibiting) dose of pargyline (15mg/kg) resulted in a time-dependent increase in punished responding. In contrast, chronic administration of the MAO-A selective inhibitor (clorgyline; 1.0mg/kg, 2mg/kg), the MAO-B selective inhibitor deprenyl (5mg/kg) or MAO-B inhibiting doses of pargyline (1.0mg/kg, 5mg/kg) were without effect. Finally, chronic treatment with the combination of a low dose of clorgyline (1.0mg/kg) and a low dose of pargyline (1.0mg/kg) did result in a time-dependent increase in punished responding. These results suggest that inhibition of both MAO-A and MAO-B is required for the eventuation of the anxiolytic effect resulting from chronic MAOI treatment.