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Background TH2 cells were thought to be a pivotal factor for initiation of the autoimmune blistering disease pemphigus. However, the role of other T-cell subsets in pemphigus pathogenesis remained unclear. Objective We aimed to characterize the exact phenotype of T cells responsible for the development of pemphigus. Methods Whole transcriptome shotgun sequencing was performed to determine differential gene expression in pemphigus lesions and skin of healthy individuals. The cutaneous cytokine signature was further evaluated by real-time quantitative PCR. In peripheral blood, the distribution of TH cell and folliclular helper (TFH) cell subsets was analyzed by flow cytometry. Finally, the capacity of TH and TFH cell subsets to induce desmoglein (Dsg)-specific autoantibodies by memory B cells was evaluated in coculture experiments. Results Transcriptome analysis of skin samples identified an IL-17A–dominated immune signature in patients with pemphigus, and Kyoto Encyclopedia of Genes and Genomes pathway analysis confirmed the dominance of the IL-17A signaling pathway. Increased expression of IL17A and associated cytokines was also detected by real-time quantitative PCR comparing lesional with perilesional or healthy skin. Interestingly, utilization of flow cytometry showed that patients with active pemphigus had elevated levels of circulating IL-17+, TH17, TFH17, and TFH17.1 cells. Notably, levels of TH17 and TFH17 cells correlated with levels of Dsg-specific CD19+CD27+ memory B cells, and patients with acute pemphigus showed higher levels of Dsg3-autoreactive TFH17 cells. Coculture experiments revealed TFH17 cells as primarily responsible for inducing Dsg-specific autoantibody production by B cells. Conclusion Our findings show that TFH17 cells are critically involved in the pathogenesis of pemphigus and offer novel targets for therapeutic intervention.

Pemphigus gehört zu den seltenen, aber potentiell lebensbedrohlichen Autoimmunerkrankungen. Typisch sind Blasen und Erosionen der Haut und der Schleimhäute. Grundsätzlich unterscheiden wir zwei Subtypen: Pemphigus vulgaris (PV) und Pemphigus foliaceus (PF). In dieser Studie wurden die klinisch-pathologischen Daten aus einem Register für bullöse Autoimmundermatosen analysiert mit dem Ziel, das Autoantikörperprofil und das Therapieansprechen bei Patienten mit PV und PF genauer zu charakterisieren.In einer retrospektiven Studie wurden die Daten von 69 Patienten mit PV und PF analysiert. Zur Beurteilung des klinischen Verlaufs, der Remissionen und Rezidive sowie des Schweregrads der Krankheit bei Erstmanifestation und während des gesamten Beobachtungszeitraums diente der ABSIS (Autoimmune Bullous Skin Intensity Score) (ABSIS). Mittels ELISA wurden die Spiegel von Anti-Desmoglein (Dsg)-1- und Anti-Dsg- IgG-Autoantikörpern im Serum bestimmt.Die mittlere Remissionszeit bei Patienten mit PV und PF betrug 63 Wochen. PV-Patienten mit Schleimhautbeteiligung zeigten eine schnellere Heilung. Bei PV-Patienten mit moderat oder stark erhöhten Anti-Dsg1-IgG-Autoantikörpern im Serum zu Beginn erfolgte im Lauf des Beobachtungszeitraums ein Absinken der Anti-Dsg3-IgG-Spiegel.Unsere Studie liefert neue Erkenntnisse zum Krankheitsverlauf bei Patienten mit PV und PF und offenbart, dass ein Phänotyp mit Schleimhautbeteiligung eine stärkere Neigung zur Remission aufweist.

Pemphigus diseases are potentially life-threatening and rare autoimmune bullous disorders characterized by blisters and erosions of the skin and mucous membranes. These disorders can be largely divided into two major subtypes: pemphigus vulgaris (PV) and pemphigus foliaceus (PF). The objective of this study was to evaluate the autoantibody profile and response to therapy of PV and PF patients by analyzing the clinicopathological data from a registry for bullous autoimmune dermatoses.In a retrospective study, data from 69 patients with PV and PF were included in the analysis. The Autoimmune Bullous Skin Intensity Score (ABSIS) was used to assess the clinical course, remissions, relapses and severity of the disease at first manifestation and throughout the observation period. ELISA was performed to assess levels of anti-desmoglein (Dsg)-1 and anti-Dsg3 IgG serum autoantibodies.The mean remission time in PV and PF patients was 63 weeks. PV patients with mucosal involvement showed a more favorable healing process. In PV patients with a moderate/high anti-Dsg1 IgG serum level at baseline, anti-Dsg3 IgG levels decreased during the observation period.Our study provides additional insights into the clinical course of patients with PV and PF, revealing that a mucosal phenotype is associated with a higher tendency towards remission.

Pemphigus vulgaris (PV) is an autoimmune blistering disease, in which autoantibodies against epidermal cadherins, such as desmoglein (Dsg)1 and Dsg3, lead to the development of blisters and erosions on the skin and mucous membranes. Autoreactive CD4+ T cells are essential for the induction and perpetuation of the disease by interaction with B cells producing autoantibodies. PV has a strong genetic association with certain human leucocyte antigen (HLA) alleles with HLA-DRB1*04:02 and LA-DQB1*05:03 being the most prevalent in patients. Recently, genome-wide association studies have provided a new approach to identify single nucleotide polymorphisms, alongside the known association with HLA alleles. Loss of tolerance against Dsgs and other autoantigens is a critical event in the pathogenesis of PV. Epitope spreading contributes to the progression of PV, leading to an extension of the Dsg-specific autoimmune response to other molecular epitopes of autoantigens, such as desmocollins or muscarinic receptors. Alterations in CD4+CD25+ FoxP3+ regulatory T cells are thought to contribute to the development of PV representing a suitable target for therapeutic interventions. Several CD4+ T-cell subsets and cytokines are involved in the pathogenesis of PV, while Th2 cells are the extensively studied population. Recently, other T cell subsets like T follicular helper cells and Th17 have gained attention as new potential players in PV pathogenesis. The involvement of local autoantibody production in the lesional skin of PV patients in tertiary lymphoid organs is currently discussed but not yet clarified. In this study, we reviewed the current knowledge about the development, characteristics and function of autoreactive T cells in pemphigus and present current new T cell-targeted therapeutic approaches.

Bullous pemphigoid (BP) is a prototypic autoimmune disorder of the elderly, characterized by serum IgG autoantibodies, namely anti-BP180 and anti-BP230, directed against components of the basal membrane zone that lead to sub-epidermal loss of adhesion. Pruritus may be indicative of a pre-clinical stage of BP, since a subset of these patients shows serum IgG autoantibodies against BP230 and/or BP180 while chronic pruritus is increasingly common in the elderly population and is associated with a variety of dermatoses. Clinical and experimental evidence further suggests that pruritus of the elderly may be linked to autoimmunity with loss of self-tolerance against cutaneous autoantigens. Thus, the objective of this study was to determine autoreactive T cell responses against BP180 in elderly patients in comparison to patients with BP. A total of 22 elderly patients with pruritic disorders, 34 patients with bullous or non-bullous BP and 34 age-matched healthy controls were included in this study. The level of anti-BP180 and anti-BP230 IgG serum autoantibodies, Bullous Pemphigoid Disease Area Index (BPDAI), and pruritus severity were assessed for all patients and controls. For characterization of the autoreactive T cell response, peripheral blood mononuclear cells were stimulated ex vivo with recombinant BP180 proteins (NH2- and COOH-terminal domains) and the frequencies of BP180-specific T cells producing interferon-γ, interleukin (IL)-5 or IL-17 were subsequently determined by ELISpot assay. Patients with BP showed a mixed Th1/Th2 response against BP180 while autoreactive Th1 cells were identified in a minor subset of elderly patients with pruritic disorders. Furthermore, our T cell characterization revealed that therapeutic application of topical clobetasol propionate ointment in BP patients significantly reduced peripheral blood BP180-specific T cells, along with clinically improved symptoms, strongly suggesting a systemic immunosuppressive effect of this treatment.

TWe aimed to characterize the exact phenotype of T cells responsible for the development of pemphigus.Whole transcriptome shotgun sequencing was performed to determine differential gene expression in pemphigus lesions and skin of healthy individuals. The cutaneous cytokine signature was further evaluated by real-time quantitative PCR. In peripheral blood, the distribution of TTranscriptome analysis of skin samples identified an IL-17A-dominated immune signature in patients with pemphigus, and Kyoto Encyclopedia of Genes and Genomes pathway analysis confirmed the dominance of the IL-17A signaling pathway. Increased expression of IL17A and associated cytokines was also detected by real-time quantitative PCR comparing lesional with perilesional or healthy skin. Interestingly, utilization of flow cytometry showed that patients with active pemphigus had elevated levels of circulating IL-17Our findings show that T

Erosive oral lichen planus (OLP) is, at times, extremely difficult to treat and has a major impact on patients’ quality of life. There are only limited therapeutic options, such as topical and systemic glucocorticoids, retinoids, and immunosuppressants with considerable side effects and limited efficacy upon chronic use. In the present individualised clinical trial, we assessed the efficacy of adjuvant intravenous immunoglobulins (IVIG; 2 g/kg/monthly cycle) in addition to the oral retinoid, acitretin, in three patients with refractory OLP over a period of two to six months. The efficacy of adjuvant IVIG treatment was evaluated using the Autoimmune Bullous Skin Disorder Intensity Score (ABSIS) which measures both extent of mucosal lesions and functional sequelae. The three OLP patients showed mixed responses to adjuvant IVIG treatment, ranging from therapeutic efficacy to a lack of response to IVIG. In light of the observed therapeutic responses and a lack of good therapeutic options, adjuvant IVIG, although costly, warrants further investigation as a treatment option for OLP.

Pemphigus is a group of rare, potentially devastating autoimmune diseases of the skin and mucous membranes with high morbidity and potentially lethal outcome. The major clinical variant, pemphigus vulgaris (PV) is caused by a loss of intercellular adhesion of epidermal keratinocytes which is induced by IgG autoantibodies against components of desmosomes. Specifically, IgG against the desmosomal adhesion proteins, desmoglein 3 (Dsg3) and desmoglein 1 (Dsg1), preferentially target their ectodomains which are presumably critical for the transinteraction and signalling function of these adhesion molecules. There is a close immunogenetic association of PV with the human leukocyte antigen (HLA) class II alleles, HLA-DRB1*04:02 and HLA-DQB1*05:03. These have been shown to be critical for the presentation of immunodominant peptides to autoreactive CD4+ T helper cells. The importance of autoaggressive T-B cell interaction in the induction of pathogenic IgG autoantibodies which directly cause epidermal loss of adhesion has been demonstrated both clinically (by the use of the anti-CD20 monoclonal antibody rituximab) and experimentally (in PV mouse models). The strong association of clinically active pemphigus with autoantibodies of the IgG4 and IgE subclasses strongly suggests that T helper 2 cells are critical regulators of the immune pathogenesis of pemphigus. Novel therapeutic approaches target autoreactive T and B cells to specifically interfere with the T cell-dependent activation of B cells leading to the generation of autoantibody-producing plasma cells. Our improved understanding of the autoantibody-driven effector phase of pemphigus has led to the introduction of novel therapies that target pathogenic autoantibodies such as immunoadsorption and drugs that block pathogenic autoantibody-induced cell signalling events.

Pemphigus Vulgaris is an autoimmune disease that results in blister formation in the epidermis and in mucosal tissues due to antibodies recognizing desmosomal cadherins, mainly desmoglein-3 and -1. Studies on the molecular mechanisms of Pemphigus have mainly been carried out using the spontaneously immortalized human keratinocyte cell line HaCaT or in primary keratinocytes. However, both cell systems have suboptimal features, with HaCaT cells exhibiting a large number of chromosomal aberrations and mutated p53 tumor suppressor, whereas primary keratinocytes are short-lived, heterogeneous and not susceptible to genetic modifications due to their restricted life-span. We have here tested the suitability of the commercially available human keratinocyte cell line hTert/KER-CT as a model system for research on epidermal cell adhesion and Pemphigus pathomechanisms. We here show that hTert cells exhibit a calcium dependent expression of desmosomal cadherins and are well suitable for typical assays used for studies on Pemphigus, such as sequential detergent extraction and Dispase-based dissociation assay. Treatment with Pemphigus auto-antibodies results in loss of monolayer integrity and altered localization of desmoglein-3, as well as loss of colocalization with flotillin-2. Our findings demonstrate that hTert cells are well suitable for studies on epidermal cell adhesion and Pemphigus pathomechanisms.

Human B cell activating factor (TNFSF13B, BAFF) is a tumor necrosis factor superfamily member. Binding its unique receptor (TNFRSF13C, BAFF-R) mediates gene expression and cell survival in B cells via activation of NFκB pathway. Furthermore, there is data indicating a role in T cell function. A functionally inhibitory isoform (ΔBAFF) resulting from the deletion of exon 3 in the TNFSF13B pre-RNA has already been reported. However, data on the complexity of post-transcriptional regulation is scarce. Here, we report molecular cloning of nine TNFSF13B transcript variants resulting from alternative splicing of the TNFSF13B pre-mRNA including BAFFX1. This variant is characterized by a partial retention of intron 3 of the TNFSF13B gene causing the appearance of a premature stop codon. We demonstrate the expression of the corresponding BAFFX1 protein in Jurkat T cells, in ex vivo human immune cells and in human tonsillar tissue. Thereby we contribute to the understanding of TNFSF13B gene regulation and reveal that BAFF is regulated through a post-transcriptional mechanism to a greater extent than reported to date.

Background Anti-laminin-γ1 (lam-γ1) pemphigoid, a recently described immunobullous disorder sharing immune serological features of bullous pemphigoid and epidermolysis bullosa acquisita (EBA), is characterized by the detection of serum IgG autoantibodies against the lam-γ1 chain, a 200 kDa heterotrimeric component of the dermal-epidermal junction (DEJ). Objective The aim of the study was to develop an easy-to-perform and reliable assay for the serological detection of anti-lam-γ1 IgG autoantibodies. The clinical appearance alone is not sufficient to establish diagnosis of anti-lam-γ1 pemphigoid and rather requires immune serological evidence of (i) IgG reactivity against the dermal portion of salt-split human skin; (ii) exclusion of IgG against other components of the DEJ; and (iii) IgG reactivity with a 200 kDa protein of dermal extracts by immunoblot analysis (IB). Methods The sera of 55 patients with anti-lam-γ1 pemphigoid were tested by IB with two recombinant heterotrimers, laminin 111 (lam-111) and laminin 421 (lam-421), as well as with a recombinant lam-γ1 chain monomer. Additionally, a total of 41 control sera from patients with EBA (n = 15), psoriasis vulgaris (PV; n = 14), and healthy controls (HC; n = 12) were tested. Results Immunoblot analysis revealed a positive reactivity with lam-111 and/or lam-421 in 46/55 (84%) of anti-lam-γ1 pemphigoid sera. Moreover, 8/9 of the initially non-reactive sera were positive with the lam-γ1 monomer, leading to an overall sensitivity of 98.2%. Analyses of 41 control sera with the three lam-γ1 recombinants led to a specificity of 88%. Specifically, 3/15 EBA sera, 1/14 PV serum and 1/12 HC serum reacted with the lam-γ1 monomer while only the 3 EBA sera reacted with lam-421. Conclusions Here we show a novel two-step IB assay using the two recombinant laminin trimers and lam-γ1 chain monomer for the detection of anti-lam-γ1 serum IgG with high sensitivity and specificity. This assay will facilitate the diagnosis and further characterization of this disease.

Autoimmune blistering diseases are examples of autoantibody-mediated, organ-specific autoimmune disorders. Based on a genetic susceptibility, such as a strong HLA-class II association, as yet unknown triggering factors induce the formation of circulating and tissue-bound autoantibodies that are mainly directed against adhesion structures of the skin and mucous membranes. Compared with other autoimmune diseases, especially systemic disorders, the pathogenicity of autoimmune blistering diseases is relatively well described. Several animal models of autoimmune blistering diseases have been established that helped to uncover the immunological and molecular mechanisms underlying the blistering phenotypes. Each in vivo model focuses on specific aspects of the autoimmune cascade, from loss of immunological tolerance on the level of T and B cells to the pathogenic effects of autoantibodies upon binding to their target autoantigen. We discuss current mouse models of autoimmune blistering diseases, including models of pemphigus vulgaris, bullous pemphigoid, epidermolysis bullosa acquisita, and dermatitis herpetiformis.

Pemphigus is an autoimmune disease in which IgG auto-antibodies (auto-ab) against the desmosomal cadherins desmoglein (Dsg) 3 and Dsg1 cause loss of epidermal keratinocyte adhesion. Aim of this study was to investigate cytokines derived from antigen-presenting cells (APC) and their relation to CD4+ T cell subpopulations and to the auto-ab response in pemphigus. In this regard, patients with pemphigus were compared to patients with myasthenia gravis (MG), an unrelated auto-ab-mediated autoimmune disease, and healthy controls. In pemphigus and MG, the plasma concentrations of the APC-derived immunomodulatory cytokine IL-27 were highly increased. Strikingly, IL-27 strongly correlated with Dsg-specific IgG auto-ab titers. T helper (Th) 17 cells were augmented in both pemphigus and MG patients while T follicular helper (Tfh) cells, which are essential in providing B cell help, were increased only in pemphigus along with increasing plasma concentrations of IL-21, a cytokine produced by Th17 and Tfh cells. Moreover, we could detect Dsg3-specific autoreactive T cells producing IL-21 upon ex vivo stimulation with Dsg3. These findings suggest that IL-27 and IL-21-producing T cells, are involved in the pathogenesis of pemphigus. The further characterization of IL-21-producing T cells and of the role of IL-27 will lead to a more defined understanding of the auto-ab response in pemphigus.