Mycophenolate is effective in the treatment of pemphigus vulgaris.

Background Pemphigus vulgaris is a potentially life-threatening autoimmune disease. Although combination therapies with prednisone and azathioprine are usually effective in controlling the disease, some patients either do not respond to this treatment or show early relapses. Objective To find out whether mycophenolate mofetil would be an effective drug in controlling pemphigus vulgaris in patients who failed initial treatment with azathioprine and prednisone. Results Twelve patients who were initially diagnosed as having pemphigus vulgaris and had relapsed while undergoing treatment with azathioprine (1.5-2 mg/kg of body weight) and prednisolone (2 mg/kg of body weight) subsequently receive…

Myeloid dendritic cell: From sentinel of immunity to key player of peripheral tolerance?

Myeloid dendritic cells (DC) are "sentinels" of immunity, ideally positioned throughout the body gateways and equipped with unique properties to transport antigens from the periphery to lymphoid tissues. They are professional antigen-presenting cells transmitting incoming infectious signals to T cells, the key players of adaptive immunity. For induction of effective antigen-specific T-cell immunity, crosstalk of DC and naive T cells is mandatory. However, besides this essential immunostimulatory function of DC, consolidated findings from the DC research field in the last 10 years have shown that DC have an additional important function. They act as pivotal players in the peripheral toleranc…

Freshly isolated mouse 4F7+ splenic dendritic cells process and present exogenous antigens to T cells.

The antibody 4F7 was reported to recognize an epitope expressed on dendritic cells (DC) from various tissues. To study the ability of splenic 4F7+ dendritic cells to process antigen for presentation to CD4+ T cells, DC were enriched using a separation procedure avoiding overnight culture which could lead to an altered phenotype. These DC were used as antigen-presenting cells (APC) in stimulation cultures of major histocompatibility complex class II-restricted T cells. It was found that they induce antigen-dependent lymphokine production by T cells and therefore could present exogenous antigens. These processing takes place intracellularly, because fixation abrogates presentation to T cells.…

Specific stabilization of the 4F7 molecule on dendritic cells by contact allergens.

Our laboratory has recently developed the monoclonal antibody 4F7 which recognizes a molecule on dendritic cells in the dermis of mice that is upregulated after application of contact allergens in vivo. Furthermore, this antibody detects an antigen on dendritic cells in spleen, lymph nodes and colon. In order to study the influence of contact allergens on the surface expression of the 4F7 molecules on dendritic cells, FACScan analysis of splenic dendritic cells was carried out after in vitro application of contact allergens. Freshly isolated splenic dendritic cells were found to be positive for 4F7, 33D1, N418 (CD11c) and MHC class II. After overnight culture the expression of the dendritic…

Therapeutic application of T cell receptor mimic peptides or cDNA in the treatment of T cell-mediated skin diseases

An 8-amino acid peptide encoding a sequence of the transmembrane region of the T cell receptor alpha chain (TCR-alpha) was shown to inhibit T cell function by preventing functional assembly of the T cell receptor (mimic peptide). To avoid systemic immunosuppression by peptide application in vivo, we used a topical application of the peptide. In the system of murine contact sensitivity, topical application of the peptide inhibited the elicitation of contact sensitivity following application of a contact allergen in sensitized animals. Alternatively, when naked DNA encoding the peptide sequence was injected into skin before application of a contact allergen to sensitized animals, local immuno…

Lymphozyten und Zytokine (V 09–V 14)

Induction of CD4+/CD25+ regulatory T cells by targeting of antigens to immature dendritic cells

AbstractCoupling of ovalbumin (OVA) to anti–DEC-205 monoclonal antibody (mAb) (αDEC) induced the proliferation of OVA-specific T cells in vivo. Expansion was short-lived, caused by dendritic cells (DCs), and rendered T cells anergic thereafter. Phenotypic analysis revealed the induction of CD25+/CTLA-4+ T cells suppressing proliferation and interleukin-2 (IL-2) production of effector CD4+ T cells. The findings were supported by 2 disease models: (1) CD4+ T-cell–mediated hypersensitivity reactions were suppressed by the injection of αDEC-OVA and (2) the application of hapten-coupled αDEC-205 reduced CD8+ T-cell–mediated allergic reactions. Thus, targeting of antigens to immature DCs through …

Flow-cytometric screening for the modulation of receptor-mediated endocytosis in human dendritic cells: implications for the development of an in vitro technique for predictive testing of contact sensitizers

The aim of this study was to explore the usefulness of human blood dendritic cells (DC) in the development of an in vitro model for predictive testing of contact sensitizers. A method was established to monitor the influence of chemicals on the intracellular targeting of antibody-crosslinked MHC class II molecules after their uptake by human DC. Using a three-colour flow-cytometric technique, freshly prepared DC were distinguished from other MHC class II-bearing cell types such as B-cells and monocytes in unseparated mononuclear cell suspensions of healthy volunteers. The assay is based on the pH-sensitivity of internalized fluorescein-coupled MHC class II specific antibodies. Quenching of …

CD83+ autologous human dendritic cells transfected with tumorpeptide CDNA: A potential tool for gene-immunotherapy?

Cellular and molecular mechanisms in the induction phase of contact sensitivity.

During the induction phase of contact sensitivity, hapten-specific Th1 cells are primed by epidermal Langerhans cells. These Langerhans cells present hapten on MHC class II molecules and provide costimulatory signals. This presentation discusses the induction of cytokines in Langerhans cells and keratinocytes by haptens and their regulatory effects on contact sensitivity. Haptens were painted on the skin of normal BALB/c mice and epidermal cells were prepared at various times thereafter. Langerhans cell-derived interleukin (IL)-1 beta mRNA was observed as early as 15 min after hapten paining. In keratinocytes, tumor necrosis factor-alpha, IL-1 alpha, IP-10, MIP-2 and IL-10 were found to be …

Alternative Methods for Skin Sensitisation Testing

Interleukin-10-treated dendritic cells modulate immune responses of naive and sensitized T cells in vivo.

Interleukin-10 is a pleiotropic cytokine known to have inhibitory effects on the accessory functions of dendritic cells. In vitro, interleukin-10 converts immature dendritic cells into tolerizing antigen- presenting cells. To assess whether interleukin-10-treated dendritic cells exert tolerizing effects in vivo, CD4+ T cells from DO11.10 ovalbumin-T cell receptor transgenic mice were transferred to syngeneic BALB/c recipients. Recipient animals were treated with ovalbumin-pulsed/unpulsed, interleukin-10-treated/untreated CD11c+ dendritic cells thereafter and ovalbumin-specific proliferation of lymph node cells was assessed by restimulation with the peptide in vitro. In prophylactic experime…

Signals involved in the early TH1/TH2 polarization of an immune response depending on the type of antigen.

Abstract Background: The early production of distinct cytokines by epidermal cells (ECs) in response to antigen exposure may govern the development of T H1 -like immune responses, such as contact sensitivity, or T H2 -like immune responses, such as IgE-dependent allergies of the immediate type, depending on the type of antigen. Objective: The aim of this study was to compare the signals induced by protein allergens with those induced by haptens in ECs and subsequently in local draining lymph node cells (LNCs) or splenocytes. Methods: BALB/c mice were primed in vivo with the protein allergens ovalbumin or birch pollen or the haptens 2,4-dinitrofluorobenzene or trinitrochlorbenzene, respectiv…

Fetal Calf Serum-Free Generation of Functionally Active Murine Dendritic Cells Suitable for In Vivo Therapeutic Approaches

Standard protocols to generate mouse dendritic cells (DC) generally use culture medium supplemented with fetal calf serum; however, reinjection in vivo of DC cultured in fetal calf serum results in priming to xenogeneic proteins that clearly limits the use of such DC. We therefore established a fetal calf serum-free culture system for the generation of murine DC from bone marrow precursors. DC can be generated fetal calf serum-free using RPMI supplemented with 1.5% syngeneic mouse serum. Although the yield of DC grown under fetal calf serum-free conditions was somewhat lower than that of the standard culture, large numbers of DC could be generated without the exposure to xenogeneic proteins…

Human Keratinocyte-Derived IL-12 Affects LC-Induced Allogeneic T-Cell Responses

Our laboratory has recently defined the cytokines involved in the early induction phase of contact sensitivity that help LC to become more potent APC and that help to direct this classical Thl immune response1,2.

Systemische Immunsuppression in Zeiten von COVID‐19: Müssen wir umdenken?

Zusammenfassung Die aktuelle SARS‐CoV‐2 Pandemie gefährdet vor allem ältere Menschen mit kardiopulmonalen und metabolischen Vorerkrankungen. In aktueller Diskussion ist jedoch auch, ob Patienten unter immunsuppressiver Therapie ebenfalls ein höheres Risiko haben, im Fall einer COVID‐19‐Erkrankung einen schweren Krankheitsverlauf zu erleiden. Grundsätzlich gibt es derzeit jedoch keine Datenlage für eine generelle Reduktion oder Pausierung einer Immunsuppression bei Patienten mit Autoimmunerkrankungen in Zeiten der SARS‐CoV‐2‐Pandemie. Da es jedoch derzeit weder eine wirksame Therapie, noch einen entsprechenden Impfschutz gibt, sollten wir uns gezielt mit der Problematik chronisch‐immunsuppri…

Immature, but not inactive: the tolerogenic function of immature dendritic cells.

The induction of antigen-specific T cell tolerance and its maintenance in the periphery is critical for the prevention of autoimmunity. Recent evidence shows that dendritic cells (DC) not only initiate T cell responses, but are also involved in silencing of T cell immune responses. The functional activities of DC are mainly dependent on their state of activation and differentiation, that is, terminally differentiated mature DC can efficiently induce the development of T effector cells, whereas immature DC are involved in maintenance of peripheral tolerance. The means by which immature DC maintain peripheral tolerance are not entirely clear, however, their functions include the induction of …

Contact sensitizers modulate mechanisms of receptor-mediated endocytosis but not fluid-phase endocytosis in murine epidermal Langerhans cells.

In order to define the influence of contact allergens on the fluid-phase endocytosis (FPE) of soluble molecules of murine epidermal Langerhans cells (LC), we studied the internalization of FITC-labeled bovine serum albumin (FITC-BSA), TRITC-labeled dextrane (TRITC-DEX) as well as horseradish peroxidase by LC. A 3-parameter flow-cytometric technique was performed for quantification of internalized FITC-BSA in LC using quantum red-labeled reagents for detection of la-antigen expression by LC and propidium iodide for exclusion of dead cells from analysis. A temperature-dependent rapid accumulation of FITC-BSA was noticed in time-course studies reaching a plateau between 1 and 2 h of in vitro c…

Human CD25+ regulatory T cells: two subsets defined by the integrins alpha 4 beta 7 or alpha 4 beta 1 confer distinct suppressive properties upon CD4+ T helper cells.

Down-regulation of autoreactive T cell responses in vivo includes cell-contact-dependent as well as contact-independent mechanisms. Infectious tolerance is a contact-dependent mechanism used by naturally occurring CD25(+) T regulatory cells (Tregs) to confer suppressive activity upon conventional CD4(+) T cells thereby generating secondary T helper suppressor cells(Th(sup)), which inhibit T cell activation via soluble mediators. Here, we describe two distinct subsets of human Tregs, characterized by expression of either the alpha(4)beta(7) integrin or the alpha(4)beta(1) integrin. Upon activation, both subsets show an enhanced expression of FoxP3, recently described as a key transcription f…

15. Mainzer Allergie-Workshop 2003

Change in expression of MGMT during maturation of human monocytes into dendritic cells.

Dendritic cells (DCs) maturated from monocytes play an important role in the immune system, not only in defense against conventional infections but also in cancer rejection. Because of the central role of DCs in tumor host defense it is highly important that DCs as well as the progenitor cell population are protected during cancer therapy. Since most anticancer drugs target DNA, the DNA repair capacity is most importance for the response of DCs and their precursor cells. Here, we studied the expression of the DNA repair protein O6-methylguanine-DNA methyltransferase (MGMT) in monocytes obtained from peripheral blood of healthy donors and DCs maturated from monocytes (moDCs). We show that MG…

Cytokines and their effects on maturation, differentiation and migration of dendritic cells.

In this review the role of cytokines in the maturation and migration of phenotypically and functionally diverse dendritic cell (DC) subpopulations is discussed and their role in the progress of differentiation from bone marrow progenitors to lymphoid DC is described. GM-CSF is the most important cytokine for the development of functional DC and acts in concert with a varying mixture of other cytokines such as IL-4, IL-1 and TNF-α to direct the development of individual DC subpopulations.

Investigation of the immune infiltrate of melanoma metastases under immune checkpoint inhibition.

9570 Background: Tumor infiltrating lymphocytes (TIL) play a crucial role in the therapeutic impact of immune checkpoint blockers. Methods: We investigated metastases from 56 melanoma patients before and during treatment with immune checkpoint blockers (i) immunohistochemically, (ii) with TCR repertoire profiling and (iii) analysis of the transcriptome. The patients were treated with ipilimumab (n = 25) or pembrolizumab (n = 23) or ipilimumab/nivolumab (n = 7); half of them had a disease control, the other half progressed as best response to treatment. Results: In contrast to previous reports immunohistochemical analysis of the immune infiltrate revealed no significant difference in the nu…

Allergic contact dermatitis: understanding the immune response and potential for targeted therapy using cytokines.

Allergic contact dermatitis is the most common job-related disease of the western world. The only available treatments are avoidance of contact with the allergen and the use of potent corticosteroids. Recently, the role of cytokines in the pathogenesis of this disease has been studied and, besides defining the key molecules and basic cellular immune responses responsible for disease development, these studies might help to develop new therapeutic strategies to target cytokines and thereby try to alter or abrogate ongoing immune reactions.

Granuloma anulare disseminatum als seltene Nebenwirkung von Allopurinol

During long-term therapy of hyperuricaemia with allopurinol (300 mg/d) two patients developed generalized granuloma annulare. The diagnoses were confirmed by histology; concomitant diseases, especially diabetes mellitus, were not detectable. Following discontinuation of allopurinol therapy, cutaneous granulomas healed without relapse. Hyperuricaemia could be controlled by low-purine diet and medication avoiding allopurinol. The clinical history of our two patients suggested a causal connection between allopurinol therapy and generalized granuloma annulare. For this reason we rate the development of this disease in both cases as a rare but significant side effect of allopurinol. This should …

Contact sensitivity as a model for T-cell activation in skin.

Contact sensitivity has served as a useful model for the primary activation of T cells in skin and skin-associated lymphoid tissue. We have been interested in the early signals necessary for the induction of an allergen-specific T-cell response, as well as the factors controlling the intensity and extent of such an immune reaction. Because cytokines qualified as possible candidate molecules involved in directing primary immune responses in skin, we studied the early changes in the cytokine pattern of the epidermis. Apart from defining a cytokine pattern specifically induced only after application of allergen, we also identified Langerhans-cell-derived interleukin (IL)-1β as the first cytoki…

Granulomatous mycosis fungoides, a rare subtype of cutaneous T-cell lymphoma

Granulomatous mycosis fungoides (GMF) is an unusual histologic subtype of cutaneous T-cell lymphoma.1 The diagnosis of GMF is usually established after observation of a granulomatous inflammatory reaction associated with a malignant lymphoid infiltrate. Epidermotropism, a clue to diagnosis in classical mycosis fungoides (MF) may be absent in about 47% of cases of GMF.2 In some instances, the granulomatous component may be intense and obscures the lymphomatous component of the infiltrate.1 There are no distinctive clinical patterns associated with GMF.1, 3

Expression of the actin-bundling protein fascin in cultured human dendritic cells correlates with dendritic morphology and cell differentiation.

Dendritic cells are key players of the immune system as they efficiently induce primary immune responses by activating naive T cells. We generated human dendritic cells from CD14+ blood precursors and investigated expression of the actin-bundling protein fascin during maturation by western blotting, immunofluorescence, and cytofluorometry. Cells obtained by culture of CD14+ blood precursors in the presence of granulocyte-macrophage colony-stimulating factor and interleukin-4, which were only weakly positive for the maturation marker CD83, expressed low amounts of fascin. Addition of a cytokine cocktail including tumor necrosis factor alpha, interleukin-1beta, interleukin-6, and prostaglandi…

Is cytokine expression responsible for differences between allergens and irritants?

Abstract Irritant and allergic contact dermatitis are two very similar diseases, and differentiating between these two can be difficult clinically. Recently, cytokines have been identified as useful tools for differentiation. Thus, our laboratory has identified an early cytokine pattern in the induction phase of contact sensitivity that is specific for allergens and is not found after epicutaneous application of irritants or tolerogens. The upregulation of the Langerhans' cell—derived signal interleukin (IL)-1β early after allergen application especially seems to be highly specific for contact allergens. This cytokine was also found to be essential for the development of epicutaneous sensit…

Treatment of relapsing idiopathic nodular panniculitis (Pfeifer-Weber-Christian disease) with mycophenolate mofetil

Idiopathic nodular panniculitis (Pfeifer-WeberChristian disease) is characterized by fever and symmetric subcutaneous nodules often located on the lower extremities.1,2 Histologically, a lobular panniculitis with a pronounced neutrophilic infiltrate is observed. The course of the disease is characterized by acute onset with fever and malaise and the simultaneous appearance of painful subcutaneous nodules. Some patients experience involvement of the intra-abdominal or retroperitoneal fat. Relapses are frequent, and a fatal outcome has been described repeatedly. Therapy usually consists of steroids in medium to high dosages, as well as immunosuppressive drugs such as azathioprine or methotrex…

Regulatory T cell-derived adenosine induces dendritic cell migration through the Epac-Rap1 pathway.

Abstract Dendritic cells (DC) are one target for immune suppression by regulatory T cells (Treg), because their interaction results in reduced T cell stimulatory capacity and secretion of inhibitory cytokines in DC. We show that DC in the presence of Treg are more mobile as compared with cocultures with conventional CD4+ T cells and form DC–Treg aggregates within 2 h of culture. The migration of DC was specifically directed toward Treg, as Treg, but not CD4+ T cells, attracted DC in Boyden chambers. Treg deficient for the ectonucleotidase CD39 were unable to attract DC. Likewise, addition of antagonists for A2A adenosine receptors abolished the formation of DC–Treg clusters, indicating a ro…

Atypical facial porokeratosis of Mibelli

Summary An atypical case of porokeratosis of Mibelli that was localized to the face is reported.

Regulatory T Cells Prevent Neutrophilic Infiltration of Skin during Contact Hypersensitivity Reactions by Strengthening the Endothelial Barrier

The healing phase of contact hypersensitivity reactions is critically dependent on regulatory T cells (Tregs), but even the early inflammatory phase, that is, 6-24 hours after induction of a contact hypersensitivity reaction, is susceptible to Treg-mediated suppression. To investigate the underlying mechanisms, we injected Tregs before the challenge and analyzed the skin-infiltrating cells as early as 6 hours later. Early on, we found mainly neutrophils in the challenged skin, but only a few T cells. This influx of neutrophils was blocked by the injection of Tregs, indicating that they were able to prevent the first wave of leukocytes, which are responsible for starting an immune reaction. …

Induction of hapten-specific tolerance by interleukin 10 in vivo.

Interleukin 10 (IL-10) is released during the induction phase of contact sensitivity and was shown in prior functional studies to convert epidermal Langerhans cells (LC) from potent inducers of primary immune responses to specifically tolerizing cells in vitro. To investigate whether IL-10 also subserves the function of a tolerizing agent in vivo ears of BALB/c or C3H mice were injected intradermally with 1-2 micrograms of recombinant mouse (rm)IL-10 8 h before epicutaneous application of 3% trinitrochlorobenzene (TNCB; a contact allergen). As a control, mice were injected with phosphate-buffered saline or IL-10 plus neutralizing amounts of anti-IL-10 mAb. 5 d later, mice were challenged wi…

T Cell Receptor Mimic Peptidesand Their Potential Application in T-Cell-Mediated Diseas e

<i>Background:</i> A T cell receptor (TCR) peptide was designed that mimics the intramembranous amino acid sequence of the TCR chain. Prior studies had shown that this mimic peptide would inhibit TCR signaling. This study was designed to investigate the use of this mimic peptide for the treatment of T-cell-mediated skin diseases. <i>Methods:</i> Synthesized mimic peptides were first tested for their T-cell-inhibitory effect in proliferation assays. Afterwards, mimic peptides were applied to murine ear skin prior to application of a contact allergen and tested for their inhibitory effect in the model of murine allergic contact sensitivity. The effect of epicutaneous t…

Insect venom immunotherapy induces interleukin-10 production and a Th2-to-Th1 shift, and changes surface marker expression in venom-allergic subjects.

Abstract The current study was carried out to elucidate the immunoregulatory changes induced by venom immunotherapy (VIT) in bee or wasp allergic subjects. All subjects included in this study had a history of severe systemic allergic reactions to stings of the respective insect as well as positive skin tests with the respective venom or venom-specific IgE in the sera. Parameters assessed in peripheral blood mononuclear cells (PBMC) before and after initiation of VIT (rush therapy reaching a maintenance dose of 100 micrograms venom injected subcutaneously within 1 week) were expression of CD3, CD4, CD8, CD45RA, CD45RO, interleukin (IL)-2 receptor (R) alpha, IL-4R, IL-12R, Fc epsilon RII, CD4…

Erfolgreiche Behandlung des systemischen Lupus erythematodes mit IgM-angereicherten Immunglobulinen

Der systemische Lupus erythematodes ist im akuten Schub eine potentiell lebensbedrohliche Erkrankung. Auch unter Einsatz potenter Immunsuppressiva sind schwere systemische Verlaufsformen oft kaum beherrschbar. Zusatzlich stellen sich im Verlauf der oft mit hohen Dosen von Steroiden in Kombination mit anderen Immunsuppressiva kontrollierten Erkrankung zahlreiche therapieinduzierte Nebenwirkungen ein. Wir berichten uber 2 Falle eines akut exazerbierten systemischen Lupus erythematodes, die auch durch Gabe hoher Dosen von Prednisolon und Cyclophosphamid/Azathioprin kaum zu kontrollieren waren. Beide Fale wurden zusatzlich zur durchgefuhrten Immunsuppression mit IgM-angereicherten hochdosierten…

Down-Regulation of CD62L Shedding in T Cells by CD39+ Regulatory T Cells Leads to Defective Sensitization in Contact Hypersensitivity Reactions

Injection of regulatory T cells (Tregs) followed by sensitization with 2,4,6-trinitrochlorobenzene induced a transient increase in size and cellularity of skin-draining lymph nodes (LNs) in mice. This led us to hypothesize that Tregs may affect the trafficking of T cells from and to peripheral LNs. Two to three hours after sensitization, we found fewer CD8+ T cells expressing CD62L in LNs compared with untreated controls. Injection of wild-type Tregs prevented this down-regulation of CD62L. In contrast, Tregs devoid of the adenosine triphosphate (ATP)-degrading ecto-enzyme CD39 were unable to do so. As for the mechanism of CD62L regulation, we found that ATP, which is released in skin upon …

Mage-3 and influenza-matrix peptide-specific cytotoxic T cells are inducible in terminal stage HLA-A2.1+ melanoma patients by mature monocyte-derived dendritic cells.

Abstract Dendritic cell (DC) vaccination, albeit still in an early stage, is a promising strategy to induce immunity to cancer. We explored whether DC can expand Ag-specific CD8+ T cells even in far-advanced stage IV melanoma patients. We found that three to five biweekly vaccinations of mature, monocyte-derived DC (three vaccinations of 6 × 106 s.c. followed by two i.v. ones of 6 and 12 × 106, respectively) pulsed with Mage-3A2.1 tumor and influenza matrix A2.1-positive control peptides as well as the recall Ag tetanus toxoid (in three of eight patients) generated in all eight patients Ag-specific effector CD8+ T cells that were detectable in blood directly ex vivo. This is the first time …

Treatment of pemphigus vulgaris with mycophenolate mofetil

different pattern of diffusion changes in a 51-year-old woman with chronic epilepsy and recurrent episodes of focal status epilepticus, for whom no aetiology could be established. Status consisted of clonic jerking of the right leg, which continued for 22 days and was followed by transient paresis. DWI during status showed decreased diffusion in the motor cortex of the right leg (relative decrease in ADC of 27%, see figure). Surprisingly, the diffusion was increased in the subcortical white matter (relative increase in ADC of 31%). On the T2-weighted image (not shown), both cortex and subcortical white matter of the corresponding region returned a high signal similar to previously reported …

CD83+ human dendritic cells transfected with tumor peptide cDNA by electroporation induce specific T-cell responses: A potential tool for gene immunotherapy.

Dendritic cells (DC) are the most potent immunostimulatory cells, with the capacity to induce primary T-cell responses. Functional autologous DC can be generated from fetal calf serum-free peripheral blood mononuclear cells in the presence of interleukin-4 and granulocyte-macrophage colony-stimulating factor and are stimulated with a defined cytokine cocktail for terminal maturation. We were able to establish a nonviral transfection protocol for these DC by electroporation. Using enhanced green fluorescent protein as a reporter gene, we achieved transfection efficiencies of up to 10%. FACScan analyses revealed a stable phenotype, and the expression of major histocompatibility complex class …

CD40 signalling induces IL-10-producing, tolerogenic dendritic cells

Dendritic cells (DC) are potent antigen-presenting cells capable to induce efficient antigen-specific T cell responses in vitro and in vivo. Herein, the maturation process is of great significance, as immature DC (iDC) are known to induce rather regulatory than effector T cell differentiation. This study was designed to characterize the role of the CD40-CD40L pathway for differentiation and function of human DC. Therefore, iDC were stimulated through CD40-CD40L interaction by transduction of DC with adenoviral vectors encoding for CD40L (Ad-CD40L). Resulting DC (CD40L-DC) were analysed concerning their phenotype, cytokine profile and T cell stimulatory capacity. Transduction induced a DC ph…

Induction of Interleukin 10–Producing, Nonproliferating Cd4+ T Cells with Regulatory Properties by Repetitive Stimulation with Allogeneic Immature Human Dendritic Cells

The functional properties of dendritic cells (DCs) are strictly dependent on their maturational state. To analyze the influence of the maturational state of DCs on priming and differentiation of T cells, immature CD83− and mature CD83+ human DCs were used for stimulation of naive, allogeneic CD4+ T cells. Repetitive stimulation with mature DCs resulted in a strong expansion of alloreactive T cells and the exclusive development of T helper type 1 (Th1) cells. In contrast, after repetitive stimulation with immature DCs the alloreactive T cells showed an irreversibly inhibited proliferation that could not be restored by restimulation with mature DCs or peripheral blood mononuclear cells, or by…

Active suppression induced by cutaneous exposure to bacterial superantigen is prevented by interleukin-12 treatmentin vivo

Exposure to the bacterial superantigen staphylococcal enterotoxin B (SEB) leads to inhibition of several immune responses and the induction of regulatory cells. The aim of this study was to characterize these regulatory cells further and to investigate the effect of interleukin-12 (IL-12) on superantigen-induced suppression. For this purpose BALB/c mice were injected subcutaneously with low doses of SEB that did not deplete the SEB-reactive V beta T cells. Intravenous transfer of unseparated local-draining lymph node cells from these SEB-treated animals suppressed the proliferative response of mononuclear spleen cells of naive syngeneic recipients for at least 3 weeks. The regulatory cells …

Induction of strong and persistent MelanA/MART-1-specific immune responses by adjuvant dendritic cell-based vaccination of stage II melanoma patients

A significant percentage of stage II melanoma patients (tumor thickness >1 mm) remain at risk of tumor recurrence after primary tumor excision. In this study, we used tumor antigen-pulsed dendritic cells as an adjuvant for immunization of these “high-risk” melanoma patients after resection of the primary tumor. A total of 13 patients were included and vaccinated 6 times every 14 days with autologous dendritic cells pulsed with a MelanA/MART-1 peptide in combination with a recall antigen. Antigen-specific immune responses were monitored before, during and up to 1 year after the last vaccination. The majority of patients exhibited increased recall antigen-specific CD4+ T cell responses upon v…

Regulatory T cell deficient scurfy mice exhibit a Th2/M2-like inflammatory response in the skin

Abstract 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.…

CD4(+) and CD8(+) anergic T cells induced by interleukin-10-treated human dendritic cells display antigen-specific suppressor activity.

Interleukin-10 (IL-10)–treated dendritic cells (DCs) induce an alloantigen- or peptide-specific anergy in various CD4+ and CD8+ T-cell populations. In the present study, we analyzed whether these anergic T cells are able to regulate antigen-specific immunity. Coculture experiments revealed that alloantigen-specific anergic CD4+ and CD8+ T cells suppressed proliferation of syngeneic T cells in a dose-dependent manner. The same effect was observed when the hemagglutinin-specific CD4+T-cell clone HA1.7 or tyrosinase-specific CD8+ T cells were cocultured with anergic T cells of the same specificity. Anergic T cells did not induce an antigen-independent bystander inhibition. Suppression was depe…

How do dendritic cells prevent autoimmunity: what is a mature dendritic cell in the mouse?

We appreciate the comment by Morel and Feili-Hariri with regard to our most-recent publication in Trends in Immunology 1xDendritic cells as a tool to induce anergic and regulatory T cells. Jonuleit, H. et al. Trends Immunol. 2001; 7: 394–400Abstract | Full Text | Full Text PDF | Scopus (384)See all References1. We certainly do not argue that other subtypes of dendritic cell (DC) might not be suitable for the induction of tolerance also, but certain experimental differences should be considered, particularly with regard to the maturational status of the murine DCs used by Feili-Hariri et al. 2xImmunotherapy of NOD mice with bone-marrow-derived dendritic cells. Feili-Hariri, M. et al. Diabete…

Systemic immunosuppression in times of COVID‐19: Do we need to rethink our standards?

Summary The current SARS‐CoV‐2 pandemic particularly endangers older people with pre‐existing cardiopulmonary and metabolic conditions. However, it is also currently under discussion whether patients under immunosuppressive therapy also have a higher risk of suffering a severe course of the COVID‐19 disease. In principle though, there is currently no data available for a general reduction or pause of immunosuppression in patients with autoimmune diseases because of the SARS‐CoV‐2 pandemic. However, since there is currently neither an effective therapy nor corresponding vaccination protection, the indication for a prolonged immunosuppressive therapy should be made with special care. In parti…

Allergen-Specific Low Zone Tolerance Is Independent of MRP8/14-, TLR4-, TLR7-, and TLR9-Mediated Immune Processes.

Programmed cell death protein 1 inhibitors in advanced cutaneous squamous cell carcinoma: real-world data of a retrospective, multicenter study

Abstract Background Cutaneous squamous cell carcinoma (cSCC) is one of the most common malignancies of the skin. Even though most patients are sufficiently treated by surgical resection, some will eventually metastasize and need systemic therapy. Phase I and II studies have shown efficacy for programmed cell death protein 1 (PD-1) inhibitors, but cohort sizes are low and real-world data especially on long-term outcome are pending. Methods Patients from six German skin cancer centers treated with PD-1 inhibitors (pembrolizumab, nivolumab or cemiplimab) for advanced cSCC were retrospectively studied. Internal patient records were analyzed for clinical outcome including response, progression-f…

Production of Extracellular Adenosine by CD73+ Dendritic Cells Is Crucial for Induction of Tolerance in Contact Hypersensitivity Reactions

Dendritic cells (DCs) express the ecto-5′-nucleotidase CD73 that generates immunosuppressive adenosine (Ado) by dephosphorylation of extracellular Ado monophosphate and diphosphate. To investigate whether CD73-derived Ado has immune-suppressive activity, 2,4-dinitrothiocyanobenzene (DNTB) was applied to skin of wild-type (WT) or CD73-deficient (CD73–/–) mice, followed by sensitization and challenge with 2,4-dinitrofluorobenzene. In this model, we show the induction of tolerance by DNTB against 2,4-dinitrofluorobenzene only in WT but not in CD73–/– mice. Analysis of skin DCs showed increased expression of CD73 after application of DNTB in WT mice. That was accompanied by elevated concentrati…

Heat-stable antigen is expressed by murine keratinocytes and delivers costimulatory signals in T-cell activation.

Heat-stable antigen (HSA), expressed by various antigen-presenting cells (APC), has been described as a costimulatory molecule for CD4+ T cells. Recently, we observed that HSA also serves as an important costimulatory molecule on epidermal Langerhans cells (LC). During these studies, low levels of HSA staining were also detected on normal murine keratinocytes (KC). To investigate whether HSA also is involved in T-cell activation by KC, normal murine KC or the spontaneously transformed KC cell-line PAM 212 were treated with PDB or PMA to induce HSA-expression. FACS analyses showed induction of HSA expression on normal murine KC, as well as PAM 212 cells. In functional assays PDB or PMA-treat…

FCS-free generation of functionally active murine dendritic cells suitable for in vivo therapeutic approaches

Induction of dendritic cell maturation and modulation of dendritic cell-induced immune responses by prostaglandins

Dendritic cells (DC) are the most potent antigen-presenting cells of the immune system. In this study we investigated the effects of various prostaglandins (PG) on the stimulatory capacity of DC. DC were generated from peripheral progenitor cells in the presence of IL-4 and GM-CSF and stimulated with IL-1, IL-6 and TNF-alpha on day 7. Simultaneously, PG (PGD(2), PGE(1), PGE(2), PGF(2 alpha), PGI(2)) were added at various concentrations (10(-5) to 10(-9) M) on day 7. In all experiments, PGE(2) had the most potent influence on the maturation of the DC, followed by other PG in the order PGE(1) > PGD(2) > PGF(2 alpha) > PGI(2). In addition, the expression of the surface molecules CD40, CD54, CD…

Contact Sensitizers Specifically Increase MHC Class II Expression on Murine Immature Dendritic Cells

Contact sensitivity is a T-cell-mediated immune disease that can occur when low-molecular-weight chemicals penetrate the skin. In vivo topical application of chemical sensitizers results in morphological modification of Langerhans cells (LC). Moreover, within 18 h, LC increase their major histocompatibility complex (MHC) class II antigens expression and migrate to lymph nodes where they present the sensitizer to T lymphocytes. We wanted to determine if such an effect could also be observed in vitro. However, because of the high genetic diversity encountered in humans, assays were performed with dendritic cells (DC) obtained from a Balb/c mouse strain. The capacity of a strong sensitizer, DN…

Modulation of Contact Sensitivity Responses by Bacterial Superantigen

Superantigens are potent modulators of the immune system, especially T cells. Therefore, we determined the influence of superantigens on the T-cell-mediated immune response, contact sensitivity. We chose the combination of staphylococcal enterotoxin B (SEB) as superantigen and 2,4-dinitrofluorbenzene (DNFB) as the contact sensitizer, because in BALB/c mice SEB reacts almost exclusively with V beta 8+ T cells, and these cells are capable of transferring contact sensitivity to DNFB from sensitized donors to naive syngeneic recipients. Pretreatment with a single intradermal injection of 50 ng SEB 24 h before DNFB exposure at the same site on the lower abdomen enhanced the induction of contact …

Dendritic cells as mediators of tumor-induced tolerance in metastatic melanoma.

Escape from immune surveillance is critical for tumor progression in metastatic melanoma. We assessed the function of melanoma-derived dendritic cells (DCs) in patients presenting simultaneously with responding (rM) or progressing (pM) melanoma metastases. These rare coincidences allowed us to compare syngeneically the function of tumor DCs. CD83+ DCs were purified freshly from large responding (rDCs) or progressing (pDCs) metastases following chemo-immunotherapy. rDCs were 5 times more potent inducers of allogeneic T-cell proliferation than the pDCs that were used as control. Phenotypic analysis showed a marked depression of CD86 expression on pDCs. Culture supernatants from pM showed prod…

Identification and Functional Characterization of Human Cd4+Cd25+ T Cells with Regulatory Properties Isolated from Peripheral Blood

A subpopulation of peripheral human CD4(+)CD25(+) T cells that expresses CD45RO, histocompatibility leukocyte antigen DR, and intracellular cytotoxic T lymphocyte-associated antigen (CTLA) 4 does not expand after stimulation and markedly suppresses the expansion of conventional T cells in a contact-dependent manner. After activation, CD4(+)CD25(+) T cells express CTLA-4 on the surface detectable for several weeks. These cells show a G1/G0 cell cycle arrest and no production of interleukin (IL)-2, IL-4, or interferon (IFN)-gamma on either protein or mRNA levels. The anergic state of CD4(+)CD25(+) T cells is not reversible by the addition of anti-CD28, anti-CTLA-4, anti-transforming growth fa…

Infectious Tolerance

Regulatory CD4(+)CD25(+) T cells (Treg) are mandatory for maintaining immunologic self-tolerance. We demonstrate that the cell-cell contact-mediated suppression of conventional CD4(+) T cells by human CD25(+) Treg cells is fixation resistant, independent from membrane-bound TGF-beta but requires activation and protein synthesis of CD25(+) Treg cells. Coactivation of CD25(+) Treg cells with Treg cell-depleted CD4(+) T cells results in anergized CD4(+) T cells that in turn inhibit the activation of conventional, freshly isolated CD4(+) T helper (Th) cells. This infectious suppressive activity, transferred from CD25(+) Treg cells via cell contact, is cell contact-independent and partially medi…

Allergen-specific immune deviation from a T H2 to a T H1 response induced by dendritic cells and collagen type I

Background: Atopy and IgE production are associated with enhanced allergen-specific TH2 responses. Therefore a causative treatment may result from the deviation of this T H2dominated immune response toward a TH1 response. Objective: This study was carried out to analyze whether dendritic cells, the most potent antigen-presenting cells that are also known to induce antigen-specific T H1 responses, are suitable for therapy of atopic diseases by shifting the allergen-specific TH2 response toward a TH1 response. Methods: Monocyte-derived dendritic cells were used to present allergens in vitro to autologous CD4 + T cells of allergic persons. Because collagen type I activates dendritic cells and …

Different Efficiency of Heat Shock Proteins (HSP) to Activate Human Monocytes and Dendritic Cells: Superiority of HSP60

Abstract One essential immunoregulatory function of heat shock protein (HSP) is activation of the innate immune system. We investigated the activation of human monocytes and monocyte-derived dendritic cells (DC) by recombinant human HSP60, human inducible HSP72, and preparations of human gp96 and HSP70 under stringent conditions, in the absence of serum and with highly purified monocytes. HSP60 induced human DC maturation and activated human DC to secrete proinflammatory cytokines. HSP72 induced DC maturation to a lesser extent, but activated human monocytes and immature DC as efficiently as HSP60 to release proinflammatory cytokines. The independence of the effects of HSP60 and HSP72 from …

Targeted Therapy in Advanced Melanoma With Rare BRAF Mutations

PURPOSE BRAF/MEK inhibition is a standard of care for patients with BRAF V600E/K–mutated metastatic melanoma. For patients with less frequent BRAF mutations, however, efficacy data are limited. METHODS In the current study, 103 patients with metastatic melanoma with rare, activating non-V600E/K BRAF mutations that were treated with either a BRAF inhibitor (BRAFi), MEK inhibitor (MEKi), or the combination were included. BRAF mutation, patient and disease characteristics, response, and survival data were analyzed. RESULTS Fifty-eight patient tumors (56%) harbored a non-E/K V600 mutation, 38 (37%) a non-V600 mutation, and seven had both V600E and a rare BRAF mutation (7%). The most frequent mu…

Induction of tumor peptide-specific cytotoxic T cells under serum-free conditions by mature human dendritic cells

Tumor vaccination strategies using antigen-pulsed dendritic cells (DC) are currently under development. We established an in vitro system using cultured DC from HLA-typed volunteers for the induction of tumor peptide-specific CD8+ T cells. The strength and specificity of the resulting CTL responses were investigated. For stimulation of syngeneic CD8+ T cells two well-defined DC populations were generated: CD1a+ immature DC cultured in the presence of GM-CSF and IL-4 and mature CD83+ DC generated by additional stimulation with a cytokine cocktail. Stimulations were performed under serum-free conditions and in the absence of exogenous cytokines. Analysis of T cell responses showed that mature…

Inhibition of human allergic T-cell responses by IL-10–treated dendritic cells: Differences from hydrocortisone-treated dendritic cells

Abstract Background: Dendritic cells (DCs) are able to induce human allergic T H 1 responses as well as T H 2 responses. Objective: In this study, we examined the effect of antiinflammatory agents such as IL-10 and hydrocortisone (HC) on the accessory function of DCs and the resulting T-cell response, especially that of T H 2 cells. Methods: Naive and memory CD4 + T cells from atopic donors were stimulated with autologous allergen-pulsed DCs generated from CD14 + monocytes by culture with GM-CSF/IL-4 and fully matured with IL-1β, TNF-α, and PGE 2 in the presence or absence of IL-10 or HC. Results: IL-10–treated DCs and, to a lesser extent, HC-treated DCs showed a decreased expression of MHC…

Dendritic cells, engineered to secrete a T-cell receptor mimic peptide, induce antigen-specific immunosuppression in vivo

A T-cell receptor mimic peptide (TCRpep) consisting of an 8-amino-acid peptide, homologous to the transmembrane region of the T-cell receptor (TCR) alpha chain, blocks T-cell activation after systemic application. When dendritic cells (DCs) were transduced to secrete the TCRpep and injected into mice, evidence of immunosuppression was observed. In a CD8-driven allergy model, the injection of DCs transduced with the TCRpep reduced inflammation markedly and in a CD4+ T cell-dependent model of multiple sclerosis (experimental autoimmune encephalitis, EAE), injection of TCRpep-secreting DCs abrogated EAE symptoms and prolonged survival. These effects were antigen specific, because transduced DC…

A comparison of two types of dendritic cell as adjuvants for the induction of melanoma-specific T-cell responses in humans following intranodal injection

Dendritic cells (DCs) elicit potent anti-tumoral T-cell responses in vitro and in vivo. However, different types of DC have yet to be compared for their capacity to induce anti-tumor responses in vivo at different developmental stages. Herein, we correlated the efficiencies of different types of monocyte-derived DC as vaccines on the resulting anti-tumor immune responses in vivo. Immature and mature DCs were separately pulsed with a peptide derived from tyrosinase, MelanA/MART-1 or MAGE-1 and a recall antigen. Both DC populations were injected every 2 weeks in different lymph nodes of the same patient. Immune responses were monitored before, during and after vaccination. Mature DCs induced …

Induction of tolerogenic DCs: ‘you are what you eat’

Abstract Dendritic cells (DCs) take up antigens using antigen receptors that can be divided into three major classes: C-type lectins, integrins and Fc receptors. These receptors facilitate effective presentation of MHC–peptide complexes to T cells, resulting in the induction of immune responses. However, we discuss recent evidence that some receptors also cause induction of tolerance. Signaling motifs within the receptors either block maturation of DCs or induce signals that render DCs tolerogenic. These DCs then either induce regulatory T cells or cause deletion of effector T cells, resulting in the induction of tolerance. Antigen receptors expressed by DCs might therefore have an importan…

Enhanced expression of IL-8 in normal human keratinocytes and human keratinocyte cell line HaCaT in vitro after stimulation with contact sensitizers, tolerogens and irritants.

Abstract To investigate the interleukin-8 production of keratinocytes after stimulation in vitro we have used various agents: (i) contact sensi-tizer (2,4-dinitrofiuorobenzene, 3-n-penladecylcatechol); (ii) tolerogen (5-methyl-3-n-pentadecylcatechol); (iii) irritant (sodium lauryl sulfate). Interleukin-8 gene expression was assessed by northern blot hybridization of the total cytoplasmic RNA extracted from subconfluent normal human keratinocyte cultures and the keratinocyte cell line HaCaT using a radiolabeled DNA probe specific for human interleukin-8. Intcrleukin-8 gene expression was markedly increased upon in vitro stimulation after 1-6 h with contact sensitizers, tolerogen and the irri…

Opening a Niche for Therapy: Local Lymphodepletion Helps the Immune System to Fight Melanoma

In this issue, Fujiwara et al. report that local ablation of CD4+ T cells in a murine B16 melanoma model, together with concomitant activation of the immune system by OX40L, leads to complete rejection of the melanomas. Rejection was driven mainly by CD8+ T cells, which infiltrated the melanomas and secreted sizeable amounts of IFN-γ. However, CD8+ T-cell infiltration also caused the recruitment of immunosuppressive myeloid-derived suppressor cells (MDSCs). Although these cells did not prevent the rejection of the melanomas, in clinical settings the long-term repopulation of tumors by MDSCs may counteract successful treatment. Thus, local ablation of CD4+ leukocytes may improve anti-melanom…

Anaphylaktischer Schock nach Lipid-Austauschchromatographie bei einer Patientin mit angeborenem IgA-Mangel

We report on a 59-year-old woman patient with selective IgA deficiency and familial hypercholesterinaemia. To lower elevated LDL levels in the patient's blood, immunoadsorption therapy with sheep-anti-human polyclonal antibodies coupled to sepharose columns was administered. During the procedure, the patient developed an anaphylactic shock requiring intensive care treatment. The patient's history revealed a fresh cell therapy with fetal sheep cells 10 years previously. Intracutaneous testing confirmed sensitization to sheep immunoglobulin, which was the most likely reason for the anaphylactic shock.

Influence of extracellular matrix proteins on the development of cultured human dendritic cells.

The development of dendritic cells (DC) is still only partly understood. Recently established culture systems using CD34+ cells or monocytes as precursor cells for the generation of DC indicate the necessity of pro-inflammatory cytokines for their development. In vivo the contact to other cells or to the proteins of the extracellular matrix might also be essential for their development. In our experiments we used granulocyte-macrophage colony-stimulating factor- and IL-4-treated human monocytes as precursor cells to investigate the interaction of DC at different maturation stages with the matrix proteins fibronectin, collagen type I and collagen type IV. We demonstrate a strong beta1-integr…

European Guidelines (S1) on the use of high‐dose intravenous immunoglobulin in dermatology

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 g…

Epidermal Cells Enhance Interleukin 4 and Immunoglobulin E Production After Stimulation with Protein Allergen

Exposure to certain allergens via epithelial tissues is the primary route for tile induction of immunoglobulin E–dependent allergies of the immediate type associated with atopic diseases. In order to address the question whether and how epithelial cells might contribute to the induction or increase of T H2 -dependent IgE production, we performed co-culture experiments of syngeneic epidermal cells and cells from the associated lymphoid tissue or spleen (responder cells) of BALB/c mice primed with ovalbumin in vivo . In the presence of ovalbumin in vitro , immunoglobulin E but not immunoglobulin G 2a production was significantly enhanced by the addition of epidermal cells, and separation of e…

Fallberichte

High-dose immunoglobulins (IVIG) are important agents in the treatment of numerous autoimmune disorders. In the field of dermatology, increasing numbers of patients with bullous autoimmune disorders and mixed connective tissue diseases have been treated. We successfully treated a patient with pemphigus vulgaris with IVIG, after he had developed osteonecrosis of his right femoral head while on azathioprine and corticosteroids. After reduction of oral corticosteroids, his disease flared dramatically. The addition of a high dose immunosuppressive regimen including azathioprine and dapsone failed to help. Thus high dose IVIG (2 mg/kg, 4 weeks interval) therapy was initiated and induced complete…

Dendritic cells as a tool to induce anergic and regulatory T cells

Abstract The induction of antigen-specific T-cell tolerance in the thymus and its maintenance in the periphery is crucial for the prevention of autoimmunity. As well as their stimulatory functions, there is growing evidence that dendritic cells, acting as professional antigen-presenting cells, also maintain and regulate T-cell tolerance in the periphery. This control function is exerted by certain maturation stages and subsets of different ontogeny, and can be influenced by immunomodulatory agents. What is the current state of knowledge of the ‘immunoregulatory' properties of dendritic cells and how might tolerance-inducing dendritic cells be relevant to therapeutic applications in humans?

Production of functional IL-18 by different subtypes of murine and human dendritic cells (DC): DC-derived IL-18 enhances IL-12-dependent Th1 development

IL-18 is a recently described cytokine that shares biological activities with IL-12 in driving the development of Th1-type T cells. As dendritic cells (DC) are very potent inducers of T cell proliferation and differentiation we wondered whether they utilize IL-18 as a factor driving Th1 development. We demonstrate by Northern blot and reverse transcription-PCR that various subtypes of human and murine DC as well as the DC-line XS contain IL-18 mRNA. When supernatants of either enriched Langerhans cells (LC) or bone marrow-derived DC were analyzed for production of IL-18 protein, IL-18 production was detected in an IL-18-specific ELISA. To assess whether the IL-18 protein released by DC is f…

Pro-inflammatory cytokines and prostaglandins induce maturation of potent immunostimulatory dendritic cells under fetal calf serum-free conditions.

Culture conditions for human dendritic cells (DC) have been developed by several laboratories. Most of these culture methods, however, have used conditions involving fetal calf serum (FCS) to generate DC in the presence of granulocyte-macrophage colony-stimulating factor and interleukin (IL)-4. Recently, alternative culture conditions have been described using an additional stimulation with monocyte-conditioned medium (MCM) and FCS-free media to generate DC. As MCM is a rather undefined cocktail, the yield and quality of DC generated by these cultures varies substantially. We report that a defined cocktail of tumor necrosis factor (TNF)-alpha, IL-1beta and IL-6 equals MCM in its potency to …

Intermittent intensified high-dose intravenous interferon alpha 2b (IFNa2b) for adjuvant treatment of stage III malignant melanoma: Pooled analysis of two randomized phase III trials (NCT00226408 and ISRCTN75125874) with 980 patients.

e20028 Background: Adjuvant high-dose interferon (HDI) treatment of patients (pts) with malignant melanoma (MM) consists of 4 weeks intravenous (IV) induction with 20 MU/m² interferon (IFN) alpha 2b followed by 11 months of 10 Mio IU/m² IFN subcutaneously (sc). It is unclear whether both parts of the regimen are mandatory for the efficacy of HDI treatment. The adjuvant phase III trials DeCOG MM-ADJ-5 and the Italian Melanoma Intergroup (IMI) trial evaluated intermittent IV HDI (iHDI) regimens as compared to standard HDI. In both trials, the experimental arm consisted of iHDI for 3 or 4 cycles, respectively. To gain more insight into the role of iHDI in the adjuvant setting we performed a p…

Europäische Leitlinien (S1) für die Anwendung von hochdosierten intravenösen Immunglobulinen in der Dermatologie.

Hintergrund und Ziele Die Behandlung schwerer dermatologischer Autoimmunerkrankungen und der toxischen epidermalen Nekrolyse (TEN) mit hochdosierten intravenosen Immunglobulinen (IVIg) ist ein bewahrtes therapeutisches Verfahren in der Dermatologie. Da eine IVIg‐Therapie in der Regel nur bei seltenen Erkrankungen oder bei schweren Fallen in Betracht gezogen wird, stutzt sich die Anwendung von Immunglobulinen zumeist nicht auf Daten aus randomisierten kontrollierten Studien, wie sie in der evidenzbasierten Medizin erforderlich sind. Da Indikationen fur die Anwendung von IVIg selten sind, ist es unwahrscheinlich, dass solche Studien in absehbarer Zeit durchgefuhrt werden. Wegen der hohen Kost…

Interleukin-10–Treated Human Dendritic Cells Induce a Melanoma-Antigen–Specific Anergy in CD8+ T Cells Resulting in a Failure to Lyse Tumor Cells

Abstract Dendritic cells (DC) are critically involved in the initiation of primary immune processes, including tumor rejection. In our study, we investigated the effect of interleukin-10 (IL-10)–treated human DC on the properties of CD8+ T cells that are known to be essential for the destruction of tumor cells. We show that IL-10–pretreatment of DC not only reduces their allostimulatory capacity, but also induces a state of alloantigen-specific anergy in both primed and naive (CD45RA+) CD8+ T cells. To investigate the influence of IL-10–treated DC on melanoma-associated antigen-specific T cells, we generated a tyrosinase-specific CD8+ T-cell line by several rounds of stimulation with the sp…

17. Mainzer Allergie-Workshop

Vaccination with Mage-3a1 Peptide–Pulsed Mature, Monocyte-Derived Dendritic Cells Expands Specific Cytotoxic T Cells and Induces Regression of Some Metastases in Advanced Stage IV Melanoma

Dendritic cells (DCs) are considered to be promising adjuvants for inducing immunity to cancer. We used mature, monocyte-derived DCs to elicit resistance to malignant melanoma. The DCs were pulsed with Mage-3A1 tumor peptide and a recall antigen, tetanus toxoid or tuberculin. 11 far advanced stage IV melanoma patients, who were progressive despite standard chemotherapy, received five DC vaccinations at 14-d intervals. The first three vaccinations were administered into the skin, 3 × 106 DCs each subcutaneously and intradermally, followed by two intravenous injections of 6 × 106 and 12 × 106 DCs, respectively. Only minor (less than or equal to grade II) side effects were observed. Immunity t…

Epidermal cytokines govern immune responses of the skin.

Prevention and reversal of superantigen-induced anergy by contact allergen exposure

The superantigen Staphylococcal enterotoxin B (SEB) and the contact allergen 2,4-dinitrofluorbenzene (DNFB) both react with V beta 8+ T-cells delivering distinct signals. Pre-treatment with DNFB painted onto the same skin site where SEB was to be injected, prevented the induction of anergy in V beta + T-cells that was otherwise induced after SEB had been injected intradermally over a period of 2 weeks. Application of the irritant sodium dodecyl sulfate (SDS) instead of DNFB did not exert this effect. Application of DNFB at a site distant from the site where SEB was injected resulted in a much weaker inhibitory influence on the induction of anergy by SEB. Established anergy of V beta 8+ T-ce…