Search

Introduction: Targeting the α7 nicotinic acetylcholine receptor (α7nAChR) has recently been suggested as a potential new treatment for fibrotic skin diseases. Here, we performed a genetic and pharmacologic approach to clarify the role of this receptor in the bleomycin (BLM) mouse model of skin fibrosis using α7nAChR KO mice. Methods: We analyzed the expression of extracellular matrix (ECM) components in murine skin using quantitative RT-PCR, pepsin digestion/SDS-PAGE of proteins and performed hydroxyproline assays as well as histological/immunohistochemical staining of skin sections. To identity the target cells of the α7nAChR agonist PHA-543613, we used murine dermal fibroblasts (MDF). We tested their response to the profibrotic cytokine transforming growth factor-β1 (TGF-β1) and utilized gene silencing to elucidate the role of the α7nAChR. Results: We confirmed our previous findings on C3H/HeJ mice and detected a suppressive effect of PHA-543613 on BLM-induced skin fibrosis in the mouse strain C57BL/6J. This antifibrotic effect of PHA-543613 was abrogated in α7nAChR-KO mice. Interestingly, α7nAChR-KO animals exhibited a basal profibrotic signature by higher RNA expression of ECM genes and hydroxyproline content than WT mice. In WT MDF, PHA-543613 suppressed ECM gene expression induced by TGF-β1. Gene silencing of α7nAChR by small interfering RNA neutralized the effects of PHA-543613 on TGF-β1-mediated ECM gene expression. Conclusion: In summary, we have identified the α7nAChR as the essential mediator of the antifibrotic effect of PHA-543613. MDF are directly targeted by PHA-543613 to suppress collagen synthesis. Our findings emphasize therapeutic exploitation of α7nAChR receptor agonists in fibrotic skin diseases.

Background Venous thromboembolism (VTE) is common and associated with high morbidity and mortality. Although chronic inflammation was not categorized as a traditional risk factor for VTE, chronic inflammation might increase the risk to develop VTE events. While studies confirmed an increased cardiovascular morbidity and mortality in psoriatic patients, data regarding the influence of psoriasis on patients' cardiovascular profile and on prognosis of patients with pulmonary embolism (PE) are sparse. Purpose We aimed to investigate the impact of psoriasis on prognosis of PE patients. Methods Hospitalized PE patients were stratified for psoriasis and the impact of psoriasis on outcome was investigated in the German nationwide inpatient sample of the years 2005–2017 (source: Research Data Center (RDC) of the Federal Statistical Office and the Statistical Offices of the federal states, DRG Statistics 2005–2017, own calculations). Results Overall, 1,076,384 hospitalizations of PE patients (53.7% females, median age 72.0 [60.0–80.0] years) were recorded in Germany 2005–2017. Among these, 3,145 patients were additionally coded with psoriasis (0.3%). Psoriatic PE patients were younger (68.0 [57.0–76.0] vs. 72.0 [60.0–80.0] years, P Psoriatic PE patients showed a lower in-hospital case-fatality rate (11.1% vs. 16.0%, P Conclusions Overall, only a minority (0.3%) of all PE cases were coded additionally with psoriasis. PE patients with psoriasis were hospitalized in median four years earlier than those without. Although psoriasis was associated with an unfavorable cardiovascular-risk and VTE-risk profile in PE patients, our data demonstrate a lower in-hospital mortality rate in psoriatic PE, which might be mainly driven by younger age. Our findings may improve the clinical management of these patients and contribute evidence for relevant systemic manifestation of psoriasis. Funding Acknowledgement Type of funding sources: None.

Monocytes and monocyte-derived cells are important players in the initiation, progression, and resolution of inflammatory skin reactions. As inflammation is a prerequisite for fibrosis development, we focused on the role of monocytes in cutaneous fibrosis, the clinical hallmark of patients suffering from systemic sclerosis. Investigating the function of monocytes in reactive oxygen species–induced dermal fibrosis, we observed that early monocyte depletion partially reduced disease severity. Low numbers of inflammatory Ly6Chigh monocytes, as well as inhibition of CCR2 and CCL2 in wild type animals by a specific L-RNA aptamer, mitigated disease parameters, indicating a pivotal role for CCR2+ inflammatory monocytes and the CCR2/CCL2 axis in fibrosis development. Of note, mice lacking splenic reservoirs failed to recruit monocytes to the skin and developed less fibrosis. Furthermore, enforced monocyte conversion into noninflammatory, patrolling Ly6Clow monocytes by a nuclear receptor Nur77–agonist also resulted in significantly impaired cutaneous inflammation and dermal fibrosis. Most evident, pronounced monocyte conversion in interferon stimulated gene 12–deficient mice with pronounced nuclear Nur77 signaling completely protected from dermal fibrosis. Our study shows that inflammatory monocytes that are recruited from splenic reservoirs play a key role in the development of skin fibrosis and can be therapeutically challenged by forced conversion via the Nur77/interferon stimulated gene 12 axis.

Melanoma is a leading cause of cancer deaths worldwide. Although immunotherapy has revolutionized the treatment for some patients, resistance towards therapy and unwanted side effects remain a problem for numerous individuals. Broad anti-cancer activities of melatonin are recognized; however, additional investigations still need to be elucidated. Herein, using various human melanoma cell models, we explore in vitro the new insights into the regulation of melanoma by melatonin and its metabolites which possess, on the other side, high safety profiles and biological meaningful. In this study, using melanotic (MNT-1) and amelanotic (A375, G361, Sk-Mel-28) melanoma cell lines, the comparative oncostatic responses, the impact on melanin content (for melanotic MNT-1 melanoma cells) as well as the mitochondrial function controlled by melatonin, its precursor (serotonin), a kynuric (N1 -acetyl-N2 -formyl-5-methoxykynuramine, AFMK) and indolic pathway (6-hydroxymelatonin, 6(OH)MEL and 5-methoxytryptamine, 5-MT) metabolites were assessed. Namely, significant disturbances were observed in bioenergetics as follows: (i) uncoupling of oxidative phosphorylation (OXPHOS), (ii) attenuation of glycolysis, (iii) dissipation of mitochondrial transmembrane potential (mtΔΨ) accompanied by (iv) massive generation of reactive oxygen species (ROS), and (v) decrease of glucose uptake. Collectively, these results together with previously published reports provide a new biological potential and make an imperative to consider using melatonin or its metabolites for complementary future treatments of melanoma-affected patients; however, these associations should be additionally investigated in clinical setting.

Background: Psoriasis is a chronic inflammatory disease which affects the body far beyond the skin. Whereas there is solid evidence that chronic skin inflammation in psoriasis drives cardiovascular disease, the impact on renal impairment and acute kidney injury (AKI) is still unclear. We aimed to analyze the impact of psoriasis on the in-hospital outcome of patients hospitalized with AKI. Methods: In this retrospective database study, we investigated data on characteristics, comorbidities, and in-hospital outcomes for all hospitalized patients with AKI stratified for concomitant psoriasis, which were collected by the Federal Office of Statistics in Germany between 2005 and 2016. Results: Among the 3,162,449 patients treated for AKI in German hospitals between 2005 and 2016, 11,985 patients (0.4%) additionally suffered from psoriasis. While the annual number of AKI patients with psoriasis increased significantly from 485 cases (4.0%) in 2005 to 1902 (15.9%) in 2016 (p &lt, 0.001), the in-hospital mortality decreased substantially (from 24.9% in 2005 to 17.4% in 2016, p &lt, 0.001). AKI patients with concomitant psoriasis were younger (70 (IQR, 60&ndash, 78) vs. 76 (67&ndash, 83) years, 0.001) and were more often treated with dialysis (16.3% vs. 13.6%, p &lt, 0.001). Presence of psoriasis in AKI patients was associated with reduced prevalence of myocardial infarction (OR 0.62, 0.001), stroke (OR 0.85, p = 0.013), and in-hospital mortality (OR 0.75, 0.001). Conclusions: AKI patients with psoriasis were hospitalized in median 6 years earlier than those without. Despite younger age, we detected higher use of kidney replacement therapy in patients with psoriasis, indicating a more severe course of AKI. Our findings might improve management of these patients and contribute evidence for extracutaneous, systemic manifestations of psoriasis.

The recent pandemic of COVID-19 has already infected millions of individuals and has resulted in the death of hundreds of thousands worldwide. Based on clinical features, pathology, and the pathogenesis of respiratory disorders induced by this and other highly homogenous coronaviruses, the evidence suggests that excessive inflammation, oxidation, and an exaggerated immune response contribute to COVID-19 pathology; these are caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This leads to a cytokine storm and subsequent progression triggering acute lung injury (ALI)/acute respiratory distress syndrome (ARDS), and often death. We and others have reported melatonin to be an anti-inflammatory and anti-oxidative molecule with a high safety profile. It is effective in critical care patients by reducing their vascular permeability and anxiety, inducing sedation, and improving their quality of sleep. As melatonin shows no harmful adverse effects in humans, it is imperative to introduce this indoleamine into clinical trials where it might be beneficial for better clinical outcomes as an adjuvant treatment of COVID-19-infected patients. Herein, we strongly encourage health care professionals to test the potential of melatonin for targeting the COVID-19 pandemic. This is urgent, since there is no reliable treatment for this devastating disease.

Targeting neuroendocrine receptors can be considered as another interesting approach to treating fibrotic disorders. Previously, we could demonstrate that tropisetron, a classical serotonin receptor blocker, can modulate collagen synthesis and acts in vitro through the α7 nicotinic acetylcholine receptor (α7nAchR). Here, we used a pharmacologic approach with specific α7nAchR agonists to validate this hypothesis. PHA-543613, an α7nAchR-specific agonist, not only prevented but also reversed established skin fibrosis of mice injected with bleomycin. Interestingly, agonistic stimulation of α7nAchR also attenuated experimental skin fibrosis in the non–inflammation driven adenovirus coding for TGFβ receptor Iact mouse model, indicating fibroblast-mediated and not only anti-inflammatory effects of such agents. The fibroblast-mediated effects were confirmed in vitro using human dermal fibroblasts, in which the α7nAchR-specific agonists strongly reduced the impact of TGFβ1-mediated expression on collagen and myofibroblast marker expression. These actions were linked to modulation of the redox-sensitive transcription factor JunB and impairment of the mitochondrial respiratory system. Our results indicate that pharmacologic stimulation of the α7nAchR could be a promising target for treatment of patients with skin fibrotic diseases. Moreover, our results suggest a mechanistic axis of collagen synthesis regulation through the mitochondrial respiratory system.

Background Scurfy mice have a functional defect in regulatory T cells (Treg), which leads to lethal multi-organ inflammation. The missing Treg function results in uncontrolled autoimmune cellular and humoral inflammatory responses. We and others have previously shown that during the course of disease scurfy mice develop severe skin inflammation and autoantibodies including anti-nuclear autoantibodies (ANA). Objective Autoimmune skin inflammation and ANA are hallmarks for the diagnosis of autoimmune connective tissue diseases; therefore we analyzed scurfy mice for typical signs of these diseases. Methods Indirect immunofluorescence was used to specify the ANA pattern in scurfy mice. Skin fibrosis was assessed by cutaneous collagen accumulation (Goldeners trichrome staining), collagen crosslinking/disorganization (Sirus red polarimetry) and quantitative PCR for fibrosis-related transcripts. The cellular components of the inflammatory infiltrates in scurfy skin were analyzed by flow cytometry and intracellular cytokine staining. Results The majority of scurfy mice developed ANA with a predominant AC-5 pattern typical for mixed connective tissue disease, especially scleroderma. Scurfy mice showed higher skin collagen content compared to WT controls with a significant tendency in upregulation of TIMP-1. CD3+CD4+ T cells in scurfy skin exhibited a strong Th2 deviation with a significant increase of IL-4, IL-5 and IL-13, and M2-polarized CD11b+MHCII+ macrophages compared to WT mice. Conclusion We show that Scurfy mice show a predominant AC-5 ANA pattern typical for mixed connective tissue disease as in scleroderma. The autoimmune inflammation in scurfy skin mainly consists of CD4+ T cells with Th2 differentiation and alternatively-activated (M2) macrophages as it is found in scleroderma with advanced fibrosis.

BACKGROUND: Bullous pemphigoid is a blistering skin disorder with increased mortality. We tested whether a strategy of starting treatment with doxycycline gives acceptable short-term blister control while conferring long-term safety advantages over starting treatment with oral corticosteroids. METHODS: We did a pragmatic, multicentre, parallel-group randomised controlled trial of adults with bullous pemphigoid (three or more blisters at two or more sites and linear basement membrane IgG or C3). Participants were randomly assigned to doxycycline (200 mg per day) or prednisolone (0·5 mg/kg per day) using random permuted blocks of randomly varying size, and stratified by baseline severity (3-9, 10-30, and >30 blisters for mild, moderate, and severe disease, respectively). Localised adjuvant potent topical corticosteroids (

Hidradenitis suppurativa (HS also named as acne inversa) is a chronic skin disease characterized by relapsing formation of abscesses, inflammatory nodules, and fistulas. In moderate-to-severe disease, HS leads to the formation of scarring and thus irreversible tissue destruction. In the past few years, two new treatment options became available: adalimumab, the first biologic therapy approved for HS (Humira®, AbbVie), and a noninvasive, device-based treatment utilizing a combination of intense pulsed light and radiofrequency (LAight® therapy, LENICURA, Germany). Here, we report a case of a Hurley stage III patient where the positive effect of adalimumab could be enhanced by simultaneously applying LAight® therapy. Moreover, long-term symptom control could be achieved under monotherapy with LAight® after adalimumab was terminated.

Background The treatment of severe dermatological autoimmune diseases and toxic epidermal necrolysis (TEN) with high-dose intravenous immunoglobulin (IVIg) is a well-established procedure in dermatology. As treatment with IVIg is usually considered for rare clinical entities or severe clinical cases, the use of immunoglobulin is not generally based on data from randomized controlled trials that are usually required for the practice of evidence-based medicine. Owing to the rarity of the indications for the use of IVIg, it is also unlikely that such studies will be available in the foreseeable future. Because the high costs of IVIg treatment also limit its first-line use, the first clinical guidelines on its use in dermatological conditions were established in 2008 and renewed in 2011. Materials and methods The European guidelines presented here were prepared by a panel of experts nominated by the EDF and the EADV. The guidelines were developed to update the indications for treatment currently considered as effective and to summarize the evidence base for the use of IVIg in dermatological autoimmune diseases and TEN. Results and conclusion The current guidelines represent consensual expert opinions and definitions on the use of IVIg reflecting current published evidence and are intended to serve as a decision-making tool for the use of IVIg in dermatological diseases.

Radiotherapy, particularly total skin electron beam therapy (TSEB), is one of the main pillars in the strategy for treatment of cutaneous T-cell lymphoma (CTCL). Low-dose TSEB has gained considerable attention since it has a minimal toxicity profile. Low-dose TSEB has been shown to yield an overall response rate up to 95 %, although the response duration is usually short. Few studies have been published on treatment outcomes after combined treatment of CTCL with TSEB and systemic therapy. Remission rates of patients who received immune checkpoint inhibitors alone ranged from 15-38 % with a two-year progression-free survival of 69 %. Given that TSEB results in rapid reduction of the disease burden in almost all patients, we hypothesized that TSEB followed by immune checkpoint inhibitors might be a reasonable treatment with a sustained effect for treatment-experienced patients with mycosis fungoides and Sezary syndrome.

Radiotherapy (RT) has an established role in the curative treatment of indolent primary cutaneous B‑cell lymphoma (PCBCL). With the role of low-dose regimens such as 2 × 2 Gy being uncertain, we compared conventional-dose RT to a low-dose approach and investigated outcome and toxicities.We retrospectively reviewed the medical records of 26 patients with 44 cutaneous lesions treated at our institution between 2007 and 2017, comprising 22 marginal zone lymphoma (PCMZL) lesions and 22 follicle center lymphoma (PCFCL) lesions. Seven lesions (16%) were treated with low-dose RT (LDRT) (4 Gy) and 37 (84%) with conventional-dose RT (≥24 Gy, median 40 Gy). Median follow-up duration was 76 months.The overall response rate (ORR) was 91% (complete response rate [CRR]: 75%). The 5‑year local control rate (LCR) was 88% and the 10-year LCR was 84%. The response rates were significantly higher following conventional-dose RT (ORR: 92% vs. 86%; CRR: 84% vs. 29%; P = 0.007). In terms of radiation dose, the rate of infield relapses (14% vs. 11%, P = 0.4) and the 5‑year LCR (86% vs. 90%, P = 0.4) were comparable in the LDRT and conventional-dose RT groups. During RT courses, about two-thirds of patients experienced mild toxicities, with grade I and II acute toxicity rates of 61% and 9%, respectively, with lower incidences of grade I (14% vs. 70%) and grade II (0% vs. 8%, P = 0.004) toxicities following LDRT.This long-term analysis confirms the excellent outcome of RT in the management of PCBCL. The LDRT concept with 4 Gy was associated with a comparable LCR and reduced rates of acute toxicity. However, the response rates were significantly lower for this group and LDRT may therefore not be recommended as standard treatment.ZIELSETZUNG: Die Strahlentherapie (RT) hat eine etablierte Rolle in der kurativen Behandlung indolenter primär kutaner B‑Zell-Lymphome (PCBCL). Die Rolle einer Niedrigdosis-Behandlung (z. B. 2 × 2 Gy) wird kontrovers diskutiert, sodass in der folgenden Studie ein Vergleich der konventionellen RT-Dosis mit einem Niedrigdosis-Konzept erfolgte und hierbei Effektivität und Toxizitäten analysiert wurden.In einer retrospektiven Analyse wurden 26 Patienten mit 44 kutanen Läsionen identifiziert, die zwischen 2007 und 2017 an unserer Klinik behandelt wurden. Hierunter waren 22 Läsionen von Marginalzonenlymphomen (PCMZL) und 22 Läsionen von Follikelzentrumslymphomen (PCFCL). Es wurden 7 Läsionen (16 %) mit Niedrigdosis-RT (LDRT) (4 Gy) behandelt und 37 Läsionen (84 %) mit einer RT in konventioneller Dosis (≥24 Gy, im Median 40 Gy). Das mediane Follow-up betrug 76 Monate.Die Gesamtansprechrate (ORR) lag bei 91 % (komplette Ansprechrate [CRR]: 75 %). Die 5‑Jahres-Lokalkontrollrate (LCR) war 88 % und die 10-Jahres-LCR 84 %. Die Ansprechraten waren nach Bestrahlung in konventioneller Dosis signifikant höher (ORR: 92 % vs. 86 %; CRR: 84 % vs. 29 %; P = 0,007). Im Hinblick auf die Rate an „Infield“-Rezidiven (14 % vs. 11 %; P = 0,4) und die 5‑Jahres-LCR (86 % vs. 90 %; P = 0,4) waren die Gruppen der LDRT und der konventionellen Bestrahlung vergleichbar. Während der RT traten Grad-I-Toxizitäten bei 61 % und Grad-2-Toxizitäten bei 9 % der Patienten auf, mit signifikant weniger Akuttoxizitäten vom Grad I (14 % vs. 70 %) und vom Grad II (0 % vs. 8 %; P = 0,004) in der LDRT-Gruppe.Diese Langzeitanalyse bestätigt die exzellenten Ergebnisse der RT in der Behandlung von PCBCL. Die LDRT mit 4 Gy war mit einer vergleichbaren LCR und niedrigeren Toxizitäten verbunden. Allerdings waren die Ansprechraten signifikant niedriger, sodass die LDRT nicht als Standard empfohlen werden kann.

Melanogenesis is a key parameter of differentiation in melanocytes and melanoma cells; therefore, search for factors regulating this pathway are strongly desired. Herein, we investigated the effects of melatonin, a ubiquitous physiological mediator that is found throughout animals and plants. In mammals, the pineal gland secretes this indoleamine into the blood circulation to exert an extensive repertoire of biological activities. Our in vitro assessment indicates an oncostatic capacity of melatonin in time-dependent manner (24, 48, 72 hours) in highly pigmented MNT-1 melanoma cells. The similar pattern of regulation regarding cell viability was observed in amelanotic Sk-Mel-28 cells. Subsequently, MNT-1 cells were tested for the first time for evaluation of melanin/melatonin interaction. Thus primary, electron paramagnetic resonance (EPR) spectroscopy demonstrated that melatonin reduced melanin content. Artificially induced disturbances of melanogenesis by selected inhibitors (N-phenylthiourea or kojic acid) were slightly antagonized by melatonin. Additionally, analysis using transmission electron microscopy has shown that melatonin, particularly at higher dose of 10(−3) mol/L, triggered the appearance of premelanosomes (stage I-II of melanosome) and MNT-1 cells synthesize de novo endogenous melatonin shown by LC-MS. In conclusion, these studies show a melanogenic-like function of melatonin suggesting it as an advantageous agent for treatment of pigmentary disorders.

Mouse models resembling systemic sclerosis can be chemically induced by application of bleomycin or hypochloric acid (HOCl). To date, little is known about inflammatory cells and their potential role in scleroderma (Scl)-related fibrosis. Therefore, we compared both Scl models to define the early immune cell subsets in relation to fibrosis-related parameters. Both agents induced a significant increase in dermal thickness and collagen deposition after 4 weeks, as hallmarks of Scl. However, clinical skin thickness, densely packed, sirius red-stained collagen bundles and collagen cross-links were more pronounced in HOCl-induced Scl. In parallel, there was a significant upregulation of procollagen α1(I), α-SMA and TGF-β transcripts in HOCl animals, whereas IL-1β and MMP-13 mRNA levels were significantly increased in bleomycin-treated mice. Flow cytometric analysis of the Scl skin demonstrated an early cellular infiltrate containing mainly CD19+ B cells, CD4+ T cells, CD11c+ DC and CD11b+ myeloid cells, the latter ones being significantly more prominent after HOCl injection. Subanalysis revealed that Scl mice exhibited a significant increase of inflammatory myeloid CD11b+ Ly6Clow-high CD64low-high cells (HOCl>bleomycin). In particular, in the HOCl model, activated dermal macrophages (CCR2low MHCIIhigh ) and monocyte-derived DC (CCR2high MHCIIhigh ) predominated over less activated CD11b+ myeloid cells. In conclusion, the two models differ in certain aspects of the murine and human scleroderma but in the HOCl model, myeloid CD11b+ MHCIIhigh cells correlate with some fibrosis-related parameters. Therefore, analysis of both models is suggested to cover a comprehensive profile of Scl symptoms but with focus on the HOCl model when the role of early myeloid immune cells will be evaluated.

Tolerance to environmental antigens that encounter the organism at interfaces like skin or gut prevents deleterious systemic immune responses. The aim of this study was to analyze whether and how low doses of haptens, by entry through the skin or gastrointestinal tract, affect the outcome of the predominantly Th1/Th17-mediated 2,4,6-trinitro-benzenesulfonic acid-induced colitis, which mimics an autoimmune bowl disease in man. Epicutaneous and oral applications of low doses of the allergen resulted in the induction of low-zone tolerance (LZT) and protected from colitis development, demonstrated by a significantly reduced inflammatory response of the gut in vivo. In line with this observation, we found a significantly diminished Th1/Th17-mediated T cell response and reduced T cell proliferation after both tolerance regimes, indicating that epicutaneous LZT is just as well efficient as oral tolerance in prevention of a gut-associated inflammatory immune response. Use of a second, unrelated hapten for LZT induction revealed an antigen-specific tolerance mechanism. Intriguingly, in the absence of hapten-activated CD4(+)CD25(+)Foxp3(+) regulatory T cells and IL-10, epicutaneous and oral LZT failed to abrogate the development of the intestinal inflammation. In conclusion, this study highlights in particular epicutaneous immunotherapies in the form of LZT through activation of CD4(+)CD25(+)Foxp3(+) regulatory T cells as treatment strategies for inflammatory, allergic, or autoimmune diseases.

IgG3 is the IgG subclass with the strongest effector functions among all four IgG subclasses and the highest degree of allelic variability among all constant immunoglobulin genes. Due to its genetic position, IgG3 is often the first isotype an antibody switches to before IgG1 or IgG4. Compared with the other IgG subclasses, it has a reduced half-life which is probably connected to a decreased affinity to the neonatal Fc receptor (FcRn). However, a few allelic variants harbor an amino acid replacement of His435 to Arg that reverts the half-life of the resulting IgG3 to the same level as the other IgG subclasses. Because of its functional impact, we hypothesized that the p.Arg435His variation could be associated with susceptibility to autoantibody-mediated diseases like pemphigus vulgaris (PV) and bullous pemphigoid (BP). Using a set of samples from German, Turkish, Egyptian, and Iranian patients and controls, we were able to demonstrate a genetic association of the p.Arg435His variation with PV risk, but not with BP risk. Our results suggest a hitherto unknown role for the function of IgG3 in the pathogenesis of PV.

Dendritic cells (DCs) are central players in the initiation and control of responses, regulating the balance between tolerance and immunity. Tolerogenic DCs are essential in the maintenance of central and peripheral tolerance by induction of clonal T cell deletion and T cell anergy, inhibition of memory and effector T cell responses, and generation and activation of regulatory T cells. Therefore, tolerogenic DCs are promising candidates for specific cellular therapy of allergic and autoimmune diseases and for treatment of transplant rejection. Studies performed in rodents have demonstrated the efficacy and feasibility of tolerogenic DCs for tolerance induction in various inflammatory diseases. In the last years, numerous protocols for the generation of human monocyte-derived tolerogenic DCs have been established and some first phase I trials have been conducted in patients suffering from autoimmune disorders, demonstrating the safety and efficiency of this cell-based immunotherapy. This review gives an overview about methods and protocols for the generation of human tolerogenic DCs and their mechanisms of tolerance induction with the focus on interleukin-10-modulated DCs. In addition, we will discuss the prerequisites for optimal clinical grade tolerogenic DC subsets and results of clinical trials with tolerogenic DCs in autoimmune diseases.

Objective.Vasculopathy is a key factor in the pathophysiology of systemic sclerosis (SSc) and the main cause for Raynaud phenomenon (RP), digital ulcers (DU), and/or pulmonary arterial hypertension (PAH). It is so far unknown how patients with SSc are treated with vasoactive agents in daily practice. To determine to which extent patients with SSc were treated with different vasoactive agents, we used data from the German Network for Systemic Scleroderma registry.Methods.The data of 3248 patients with SSc were analyzed.Results.Patients were treated with vasoactive drugs in 61.1% of cases (1984/3248). Of these, 47.6% received calcium channel inhibitors, followed by 34.2% treated with angiotensin-converting enzyme (ACE) inhibitors, 21.1% treated with intravenous (IV) prostanoids, 10.1% with pentoxifylline, 8.8% with angiotensin 1 receptor antagonists (AT1RA), 8.7% with endothelin 1 receptor antagonists (ET1RA), 4.1% with phosphodiesterase type 5 (PDE5) inhibitors, and 5.3% with others. Patients with RP received vasoactive therapy in 63.3% of cases, with DU in 70.1%, and with PAH in 78.2% of cases. Logistic regression analysis revealed that patients with PAH were significantly more often treated with PDE5 inhibitors and ET1RA, and those with DU with ET1RA and IV prostanoids. In addition, 41.8% of patients were treated with ACE inhibitors and/or AT1RA. Patients registered after 2009 received significantly more often ET1RA, AT1RA, and IV prostanoids compared with patients registered prior to 2005.Conclusion.These data clearly indicate that many patients with SSc do not yet receive sufficient vasoactive therapy. Further, in recent years, a marked change of treatment regimens can be observed.

Systemic sclerosis (SSc) is one of the most complex systemic autoimmune diseases with multi-organ involvement and heterogeneous clinical manifestations. The exact etiology of SSc is still unknown. However, identified target structures are components of endothelial cells, the innate/adaptive immune systems and fibroblasts, resulting in the hallmarks of the disease in form of inflammation/autoimmunity, vasculopathy and fibrosis of the skin and internal organs. There has been a large body of evidence that the adaptive immune system with autoreactive T and B cells producing autoantibodies plays a central role in the pathogenesis of SSc but the role of earlier pathogenic processes involving the innate immune system, is far from being understood. There is strong evidence that a dysregulation of innate lymphoid cells and myeloid cells critically contributes to early pathogenic events in SSc. As disruption of vascular homeostasis and a fibroproliferative vasculopathy are hallmarks of early SSc, intravascular processes including platelet activation and interaction with neutrophils and monocytes, may even be upstream of innate immune deviation. Therefore, further studies of the dysregulated innate immune system may provide insights into novel and potentially curative treatments of SSc. In this review, we highlight the most relevant findings regarding the involvement of innate immune cells during the early stage of cutaneous fibrosis in SSc, with emphasis on the role of neutrophils, myeloid cells and innate lymphoid/NK cells in the pathogenesis of SSc and their potential as therapeutic targets for this difficult-to-treat autoimmune disease.

Interferon-α (IFN-α) is the only drug approved for adjuvant therapy of malignant melanoma and is also used in the treatment of hematological and solid tumors. Along with its proven clinical efficacy, IFN-α produces several side effects, particularly with regard to autoimmune disorders. Curious about symptoms of autoimmunity during IFN-α therapy, we asked whether IFN-α directly impacts on immune tolerance. We found that IFN-α does alter the function of tolerogenic dendritic cells (DC) as well as of induced and naturally occurring T-regulatory cells (nTregs). IFN-α blocks the tolerogenic phenotype of DC by inducing maturation and thus preventing the induction of inducible Tregs by DC. It also has direct effects on nTregs. IFN-α reduces cAMP in Tregs via ERK/phosphodiesterase-mediated pathways. Since cAMP is essentially involved in suppression by nTregs, the IFN-α-dependent reduction of cAMP levels abolishes the suppressive capacity of nTregs. Therefore, Tregs are incapable of suppressing the activity of effector T cells and natural killer cells, resulting in tumor rejection. Thus, IFN-α overcomes immunological tolerance processes, leading to an improved immunostimulation and efficient tumor rejection, but also increases the risk of autoimmunity.

Background & Aims Wheat amylase-trypsin inhibitors (ATIs) are nutritional activators of innate immunity, via activation of the toll-like receptor 4 (TLR4) on myeloid cells. We aimed to characterize the biologic activity of ATIs in various foods and their effect on intestinal inflammation. Methods We selected 38 different gluten-containing and gluten-free products, either unprocessed (such as wheat, rye, barley, quinoa, amaranth, soya, lentils, and rice) or processed (such as pizza, pasta, bread, and biscuits). ATIs were extracted and their biological activities determined in TLR4-responsive mouse and human cell lines. Effects of oral ATIs on intestinal inflammation were determined in healthy C57BL/6 mice on a gluten-free or ATI-free diet and in mice given low-level polyinosinic:polycytidylic acid or dextran sodium sulfate to induce colitis. Parameters of innate and adaptive immune activation were determined in duodenum, ileum, colon, and mesenteric lymph nodes. Results Modern gluten-containing staples had levels of TLR4-activating ATIs that were as much as 100-fold higher than in most gluten-free foods. Processed or baked foods retained ATI bioactivity. Most older wheat variants (such as Emmer or Einkorn) had lower bioactivity than modern (hexaploid) wheat. ATI species CM3 and 0.19 were the most prevalent activators of TLR4 in modern wheat and were highly resistant to intestinal proteolysis. Their ingestion induced modest intestinal myeloid cell infiltration and activation, and release of inflammatory mediators—mostly in the colon, then in the ileum, and then in the duodenum. Dendritic cells became prominently activated in mesenteric lymph nodes. Concentrations of ATIs found in a normal daily gluten-containing diet increased low-level intestinal inflammation. Conclusions Gluten-containing cereals have by far the highest concentrations of ATIs that activate TLR4. Orally ingested ATIs are largely resistant to proteases and heat, and increase intestinal inflammation by activating gut and mesenteric lymph node myeloid cells.

Summary Background: No consistent data are available on the currently employed diagnostic tools for autoimmune bullous diseases in Germany. The aim of this survey was to describe currently performed diagnostic methods for bullous autoimmune diseases in German dermatology departments. Methods: A standardized questionnaire evaluated the available diagnostic methods i. e. direct immunofluorescence microscopy (IFM), indirect IFM, commercial ELISA systems, and non-commercial serological tests as well as the number of samples per year in all 34 university and 39 non-university dermatology departments. Results: The overall return rate was 89 %, 100 % and 79 % for the university and non-university departments, respectively. Direct IFM was the most frequently used method and was applied in 98 % of the responding departments. In 74 % of the responding departments, indirect IFM was used mainly on monkey esophagus and human salt-split skin. Commercial ELISA systems were employed in 58 % of the clinics; all of them used anti-desmoglein ELISA, while anti-BP180 and anti-BP230 ELISA were established in 49 % and 48 % of departments, respectively. Non-commercial analytic methods were only performed in 22 % of the departments. Conclusions: The high return rate of this survey allows a relatively precise description of the current diagnostic methods used in German dermatology departments. Standard diagnostic tests are available nationwide and in bullous pemphigoid and pemphigus, the antigen-specific detection of autoantibodies is routinely performed in half of the departments. Rare disorders may be diagnosed by cooperation with some specialized centers.

Myeloid-derived suppressor cells (MDSC) are a heterogeneous cell population characterized by immunosuppressive activity. Elevated levels of MDSC in peripheral blood are found in inflammatory diseases as well as in malignant tumors where they are supposed to be major contributors to mechanisms of tumor-associated tolerance. We investigated the frequency and function of MDSC in peripheral blood of melanoma patients and observed an accumulation of CD11b(+) CD33(+) CD14(+) HLA-DR(low) MDSC in all stages of disease (I-IV), including early stage I patients. Disease progression and enhanced tumor burden did not result in a further increase in frequencies or change in phenotype of MDSC. By investigation of specific MDSC-associated cytokines in patients' sera, we found an accumulation of IL-8 in all stages of disease. T-cell proliferation assays revealed that MDSC critically contribute to suppressed antigen-specific T-cell reactivity and thus might explain the frequently observed transient effects of immunotherapeutic strategies in melanoma patients.

• regulatory T cells • tolerance • signal transduction • autoimmunity • allergies • cancer Summary Regulatory T cells (Tregs) are essential for induction and maintenance of immunological tolerance. They contribute to prevention of autoimmunity by control and modulation of immune responses. The prevalence of autoimmune diseases, chronic infections, cancer and allergies has markedly increased in the last decades. In additions the treatment of these disorders is often unsatisfactory so that improvements are needed. This has stimulated intensive research in the biology of Tregs. Recent studies revealed that naturally occurring CD4 + CD25 + Tregs (nTregs) and induced Tregs (iTregs) are critical for the control of inadequate immune reactions. In humans, various iTreg populations are generated to inhibit naive as well as activated effector T cells. Key molecules of signal transduction, essential for suppressor function of iTregs, have been identified and may be target molecules to modulate the activity of suppressor T cells with novel biologicals. Precise insight into the properties of Tregs may contribute to the development of innovative therapeutic approaches which directly affect Tregs in patients or use adoptive transfer of Tregs.

The treatment of severe autoimmune skin diseases and of toxic epidermal necrolysis (ICD: L51.2) with high-dose intravenous immunoglobulins (IVIg) is an established therapeutic procedure in dermatology. As IVIg are usually only administered in rare autoimmune diseases or in particularly severe disease courses, use of immunoglobulins in dermatology is commonly not based on experience from controlled and randomized studies typically demanded by evidence-based medicine. In face of the rarity of indications for IVIg it is improbable that such studies will be performed in the foreseeable future. Further, as the high costs of IVIg treatment limits its use as first-line therapy, no clear guidelines exist yet on IVIg use in skin diseases. The present recommendation is based on a consensus of the Working Group on European Guidelines of the EDF (European Dermatology Forum) and the EADV (European Association of Dermato-Venereology) and should provide aid in decision making for the use of IVIg in treating dermatologic diseases

Autoimmune diseases can initially present as chronic urticaria. We describe the course of a patient with hypocomplementemic urticarial vasculitis syndrome (HUVS) as well as his successful treatment with high-dose intravenous immunoglobulins (IVIG). HUVS was diagnosed clinically and confirmed by histology and laboratory studies. After only one cycle with IVIG (2 g/kg) all HUVS symptoms were significantly decreased.

Background The induction of tolerance may be a promising target of strategies aimed at preventing harmful allergic diseases. Low zone tolerance (LZT), induced by epicutaneous application of low doses of contact allergens, inhibits the development of T C 1-mediated contact hypersensitivity (CHS). Objective We evaluated the effect of systemic (oral, intravenous) administration of low amounts of haptens on specific immune reactions and tolerance induction. Methods By using the mouse model of LZT, we analyzed immune reactions in vivo (skin inflammation) and T-cell responses in vitro after oral, intravenous, or epicutaneous application of low amounts of the contact allergen 2,4,6-trinitro-1-chlorobenzene (TNCB). Results Subimmunogenic doses of TNCB applied orally and intravenously induced a significant tolerance reaction in vivo comparable to epicutaneously tolerized mice, indicating that LZT is a systemically mediated tolerance reaction. In vitro analysis in all models of LZT revealed the generation of IL-10 secreting, regulatory CD4 + T cells that were absolutely required for the development of hapten-specific CD8 + T C 2 cells. Adoptive transfer experiments identified CD8 + T C 2 cells as effector T cells of LZT inhibiting the development of CHS-promoting T C 1 cells and consequently the manifestation of CHS. These suppressor CD8 + T C 2 cells were found as well in skin-draining as in mesenteric lymph nodes and in the spleen of tolerized animals independent of the route of tolerization. Conclusion These data indicate that systemic uptake and presentation of small amounts of haptens (eg, contact allergens, drugs, metals) induce the development of LZT and thus prevent inappropriate activation of the immune system and protect from allergic diseases. Clinical implications These findings will be of particular importance because tolerance induction by protocols applying subimmunogenic, low amounts of haptens may be used as tools for immunotherapy in allergic and autoimmune diseases.

The melanosomal protein TRP2 expressed by melanocytes and most melanoma cells is an attractive, clinically relevant model antigen for the experimental development of melanoma immunotherapy in mice. A peptide shared by murine and human TRP2 can be recognized by melanoma-reactive CTL in C57BL/6 mice, as well as in human melanoma patients. Previous experiments demonstrated that gene gun immunization of mice with plasmid DNA encoding autologous murine TRP2 was unable to induce protective immunity against B16 melanoma cells naturally expressing TRP2. In the present study, we investigated whether the use of cDNA encoding xenogeneic human TRP2, which is highly homologous to murine TRP2, would be more effective. Genetic immunization of mice with human TRP2 resulted in coat depigmentation as a sign of autoimmune-mediated destruction of melanocytes and provided significant protection against metastatic growth of B16 melanoma. Induction of protective immunity was associated with TRP2-reactive antibodies and CD8+ T cells. Furthermore, immunization with recombinant adenovirus was more effective than immunization with plasmid DNA using the gene gun. Our results provide new insights for the development of antigen-specific immunotherapy of melanoma. Int. J. Cancer 86:89–94, 2000. © 2000 Wiley-Liss, Inc.

The ability of regulatory T cells (Tregs) to promote immunological tolerance represents an important obstacle in cancer immunotherapy. We have recently discovered that the clinically established immunotherapeutic agent interferon α (IFNα) inactivates the suppressive functions of human Tregs. Here, we outline the mechanisms whereby IFNα mediates this important function and discuss its therapeutic implications for cancer immunotherapy.

The contact dermatitis is a frequent occupation-related skin disease, which causes considerable distress in affected persons and immense cost for the society. In the last decades several murine systems of tolerance to contact allergens have been established to analyze the underlying immunological mechanisms and to develop new prophylactic and therapeutical strategies. The model of low zone tolerance to contact allergens may offer the advantage to investigate the physiological situation in humans. For the induction of the low zone tolerance subsensitizing doses of haptens were epicutaneously applicated onto the skin inducing antigen-specific CD8+ Tc2 suppressor cells.

It is well established that allergy development can be prevented by repeated low-dose exposure to contact allergens. Exactly which immune mechanisms are responsible for this so-called low zone tolerance (LZT) is not clear, although CD8⁺ suppressor T cells are known to have a role. Here, we show that TNF released by tolerogenic CD11⁺CD8⁺ DCs located in skin-draining lymph nodes is required and sufficient for development of tolerance to contact allergens in mice. DC-derived TNF protected mice from contact allergy by inducing apoptosis in allergen-specific effector CD8⁺ T cells via TNF receptor 2 but did not contribute to the generation and function of the regulatory T cells associated with LZT. The TNF-mediated killing mechanism was induced in an allergen-specific manner. Activation of tolerogenic DCs by LZT CD8⁺ suppressor T cells and enhanced TNF receptor 2 expression on contact allergen-specific CD8⁺ effector T cells were required for LZT. Our findings may explain how tolerance protects from allergic diseases, which could allow for the development of new strategies for allergy prevention.

Background The induction of cellular immune responses to melanocyte-specific enzymes such as the tyrosinase family of proteins is the goal of various clinical studies for the immunotherapy of melanoma. Tyrosinase-related protein-2 (TRP2) is an attractive model antigen for preclinical studies in C57BL/6 mice because it is naturally expressed by the murine B16 melanoma and can be recognized by self-reactive cytolytic T lymphocytes (CTL). Here we describe efforts to develop genetic immunization with dendritic cells (DC) for the immunotherapy of melanoma in this clinically relevant system. Methods Recombinant adenoviruses encoding green fluorescent protein (Ad-EGFP) and murine TRP2 (Ad-mTRP2) were constructed using Cre-loxP-mediated recombination. DC were generated in vitro from precursors in bone marrow and transduced with Ad-EGFP or Ad-mTRP2. Mice were immunized by direct injection of adenovirus or by injection of Ad-transduced DC. Induction of tumor immunity was assessed by intravenous challenge with B16 melanoma cells and enumeration of experimentally induced lung metastases. Results Flowcytometric analysis of DC transduced with Ad-EGFP demonstrated endogenous fluorescence due to cytoplasmatic expression of EGFP in 30–60% of cells. Ad-EGFP-transduced DC simultaneously displayed the DC-specific marker NLDC145 and high levels of MHC and costimulatory molecules on their cell surface. Transduction of DC with Ad-mTRP2 resulted in strong intracellular expression of TRP2 which could be readily detected by immunostaining. Importantly, immunization of mice with cultured Ad-mTRP2-transduced DC completely prevented the development of lung metastases following an intravenous challenge with B16 melanoma cells. This striking protective effect was observed with both the intravenous and the subcutaneous route of DC immunization. In vivo depletion of T-cell subsets suggested that the protective effect of an immunization with Ad-mTRP2-transduced DC involved both CD8+ and CD4+ T-cells. Conclusions Our results demonstrate that DC-based genetic immunization of mice with TRP2, a clinically relevant melanocyte-specific self-antigen, induces effective cellular immunity and prevents metastatic growth of B16 melanoma cells in vivo. Copyright © 1999 John Wiley & Sons, Ltd.

Background IgE- and T-cell cross-reactivity contribute to the birch pollen–food syndrome. Objectives We performed a comprehensive analysis of T-cell cross-reactivity in primary cell cultures, facilitating the identification of allergen-specific T-cell subpopulations from individual patients. Methods Patients with birch pollen allergy and associated food allergy to hazelnuts, carrots, or both were analyzed for IgE cross-reactivity, T-cell responses, and T-cell cross-reactivity to recombinant Bet v 1.0101 (Bet v 1; birch), Cor a 1.0401 (Cor a 1; hazelnut), and Dau c 1.0104 (Dau c 1; carrot). A novel flow cytometry–based method using a 2-step staining process with fluorescent dyes was established to identify subpopulations of cross-reactive T cells. Results IgE-binding inhibition tests of individual sera revealed that the vast majority of Cor a 1–reactive IgE was cross-reactive to Bet v 1, whereas Bet v 1–reactive IgE was only partially inhibited by preincubation with Cor a 1. Primary stimulation of T cells with Bet v 1 or Cor a 1 resulted in a significant increase in specific responses to Cor a 1 or Bet v 1 after secondary stimulation, respectively, indicating T-cell cross-reactivity between birch and hazelnut allergens in all patients of the study cohort. Preactivation with Dau c 1 induced less pronounced effects. A novel flow cytometry–based proliferation assay identified a predominant Cor a 1/Bet v 1–cross-reactive T-cell subpopulation within highly Bet v 1/Cor a 1–responsive T cells. Conclusion Analysis of primary allergen-specific T cells combined with flow cytometry–based proliferation assays facilitates investigation of allergen-specific T-cell subpopulations in subjects and might be helpful to evaluate the effect of birch-specific immunotherapy on pollen-associated food allergies.