Pathogenesis Of Pemphigus Vulgaris Research Articles

HDAC1-mediated regulation of KDM1A in pemphigus vulgaris: unlocking mechanisms on ERK pathway activation and cohesion loss.

Pemphigus vulgaris (PV) is an autoimmune skin disorder characterized by the loss of cell cohesion, with the histone deacetylase 1 (HDAC1) and lysine demethylase 1A (KDM1A) playing critical roles in its pathogenesis. This study aimed to elucidate the molecular mechanisms behind PV, focusing on the function of HDAC1 and KDM1A in disease onset and progression. Based on in vitro and in vivo PV models, we observed a significant increase in HDAC1 mRNA and protein levels in skin tissues of PV patients. Inhibition of HDAC1 ameliorated cell damage and reduced the loss of cell cohesion in human epidermal keratinocytes (HEKs) induced by PV-IgG. Our findings suggest that HDAC1 regulates KDM1A expression through deacetylation, with a notable deficiency in KDM1A expression in PV. Overexpression of KDM1A mitigated cell damage and cohesion loss. The extracellular signal-regulated kinase (ERK) pathway serves as a downstream executor of the HDAC1/KDM1A axis. Inhibiting HDAC1 and increasing KDM1A expression suppressed ERK phosphorylation, reducing PV-related apoptosis. These insights provide a new perspective on treating PV, highlighting the therapeutic potential of targeting HDAC1 expression. The regulatory mechanism of the HDAC1/KDM1A/ERK axis offers crucial clues for understanding PV pathogenesis and developing novel treatments.

Environmental triggers of pemphigus vulgaris and bullous pemphigoid: a case control study.

Previous case-control studies have suggested that environmental factors including exposure to pesticides and organic materials, diet and medications have an important role in the pathogenesis of pemphigus vulgaris. These studies lacked geographical population controls and had less than three controls per case. To identify environmental and occupational risk factors associated with the development of pemphigus vulgaris (PV) and bullous pemphigoid (BP). Cases were patients with PV (n = 25) and BP (n = 29) recruited from 2009 to 2017. Controls for PV (n = 72) and BP (n = 84) were recruited from the general population via electoral commission matching, matched for age, sex, residential location, and ethnicity. Data about demographics, environmental exposures and occupational exposures, was collected using a structured questionnaire. Conditional logistic regression analysis was undertaken using SPSS software to identify significant variables. Significant factors associated with PV included the daily consumption of leeks (odds ratio (OR) 3.6; p = 0.025), mustard oil (OR = 4.4; p = 0.049), tomatoes (OR = 4.735; p = 0.032), multivitamins (OR 3.6; p = 0.009), alcohol (0.039), and calcium supplements (OR = 44, p < 0.001). Other associated factors included the number of lifetime sunburns (p = 0.019), high levels of mental stress (p < 0.001), and the use of lime household cleaning products (p < 0.001), Significant factors associated with BP included the daily consumption of green or herbal tea (OR = 3.7; p = 0.004), fish oil (OR = 5.7; p < 0.001), calcium supplements (OR = 6.1; p < 0.001), multivitamins (OR = 2.6; p = 0.043), and glucosamine (OR = 3.0; p = 0.046). The use of lime household cleaning products (p < 0.001) and high levels of mental stress (p = 0.007) were also associated with BP. Dietary factors containing thiol groups such as leeks, tomatoes, and mustard oil may be potential triggers for PV. High levels of mental stress, the use of supplementary medications such as calcium and multivitamins, and chemical cleaning products containing lime may be associated with an increased risk of developing both PV and BP. Lifestyle changes should be part of routine management for these patients.

Proteomic Analysis Reveals Oxidative Phosphorylation and JAK-STAT Pathways Mediated Pathogenesis of Pemphigus Vulgaris.

Pemphigus vulgaris (PV) stands as a rare autoimmune bullous disease, while the precise underlying mechanism remains incompletely elucidated. High-throughput proteomic methodologies, such as LC-MS/MS, have facilitated the quantification and characterisation of proteomes from clinical skin samples, enhancing our comprehension of PV pathogenesis. The objective of this study is to elucidate the signalling mechanisms underlying PV through proteomic analysis. Proteins and cell suspension were extracted from skin biopsies obtained from both PV patients and healthy volunteers and subsequently analysed using LC-MS/MS and scRNA-seq. Cultured keratinocytes were treated with PV serum, followed by an assessment of protein expression levels using immunofluorescence and western blotting. A total of 880, 605, and 586 differentially expressed proteins (DEPs) were identified between the lesion vs. control, non-lesion vs. control, and lesion vs. non-lesion groups, respectively. The oxidative phosphorylation (OXPHOS) pathway showed activation in PV. Keratinocytes are the major cell population in the epidermis and highly expressed ATP5PF, ATP6V1G1, COX6B1, COX6A1, and NDUFA9. In the cellular model, there was a notable increase in the expression levels of OXPHOS-related proteins (V-ATP5A, III-UQCRC2, II-SDHB, I-NDUFB8), along with STAT1, p-STAT1, and p-JAK1. Furthermore, both the OXPHOS inhibitor metformin and the JAK1 inhibitor tofacitinib demonstrated therapeutic effects on PV serum-induced cell separation, attenuating cell detachment. Metformin notably reduced the expression of V-ATP5A, III-UQCRC2, II-SDHB, I-NDUFB8, p-STAT1, p-JAK1, whereas tofacitinib decreased the expression of p-STAT1 and p-JAK1, with minimal impact on the expression of V-ATP5A, III-UQCRC2, II-SDHB, and I-NDUFB8. Our results indicate a potential involvement of the OXPHOS and JAK-STAT1 pathways in the pathogenesis of PV.

Biomarkers in Pemphigus Vulgaris: A Systematic Review.

Pemphigus vulgaris (PV) is a rare intraepidermal blistering disease that is potentially life-threatening due to risk of infection and failure of skin barrier function. The identification of biomarkers has the potential to provide diagnostic utility and identify new therapeutic targets. The objective of this systematic review is to identify all potentially relevant PV biomarkers, categorize them, and identify trends to determine the involvement of T-cell-mediated, B-cell-1mediated, and innate immune-mediated pathways in PV pathogenesis. Medline and Embase databases were searched according to Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines, resulting in the inclusion of 66 studies that reported on a total of 2463 patients and 146 unique biomarkers. Biomarkers were categorized into T-cell-mediated, B-cell-mediated, and innate immune system pathways. The most notable biomarkers trends include elevations in IL-4, IL-6, IL-17A, anti-Dsg1/3 autoantibodies, and a reduction in Treg cells and FOXP3. The results of this review support current theories of PV pathogenesis, with increased Th2 activity, increased Th17 activity, decreased Treg activity, and production of anti-Dsg1/3 autoantibodies being observed. Targeting of IL-4 and IL-6 may provide therapeutic benefit. However, more research is required to validate biomarkers for clinical utility and assess viability as therapeutic targets.

Alteration of reactive oxygen species master transcription factor Nrf2 in keratinocytes exposed to monoclonal pathogenic antibody AK23 against desmoglein-3 in pemphigus vulgaris

Keratinocytes in mucosal and skin tissues maintain tissue integrity via desmosomes and desmoglein-3 (Dsg3). Pemphigus Vulgaris (PV) is a life-threatening autoimmune blistering disease characterized by autoantibodies against Dsg3, disrupting desmosomes. Nuclear factor erythroid 2–related factor 2 (Nrf2) regulates oxidative stress responses crucial for skin tissue protection. Although the pathogenesis of PV is known, the detailed molecular events remain unclear. This study investigates changes in Nrf2 expression in keratinocytes following pathogenic anti-Dsg3 antibody AK23 exposure, using dose- and time-dependent studies employing immunofluorescence analysis. N/TERT keratinocytes were cultured in keratinocytes serum-free medium and treated with AK23 at varying doses (5 µg/mL,40µg/mL,75µg/mL) and durations (2, 6, 24 h). Immunofluorescence staining was performed to assess the expression of Nrf2 and Dsg3. All fluorescent images were analyzed using ImageJ software. A dose-dependent increase in Dsg3 was noted following AK23 treatment, while Nrf2 expression and subcellular localization varied. Time-course analyses showed decreased Nrf2 at 24 h and increased Dsg3 levels. Early time-point (2 and 6 h) variations were evident in Nrf2 levels. This study highlights the impact of AK23 on Nrf2 expression, potentially disrupting Nrf2-mediated cytoprotection and implicating oxidative stress (ROS generation) in PV pathogenesis. Further investigation is necessary to validate the findings.

Distorted frequency and functionality of natural killer cells in pemphigus vulgaris: A potential therapeutic target

Pemphigus vulgaris (PV) is a rare autoimmune disorder where autoantibodies target the desmosomal proteins resulting in blistering of oral mucosa and skin. While the pathogenesis of PV is mainly mediated by the adaptive immune system, key players of innate immunity are also emerging. This study outlines the phenotypic as well as functional attributes of NK cells in PV. Through in-depth analysis using flow cytometry we identified an increase in the frequency of CD56+ CD3- NK cells and their subtypes in periphery. Along with this there is an increased frequency of IFNγ+ CD56bright CD16dim NK cells. mRNA expression of sorted NK cells for differentially expressed genes, particularly key transcription factors such as T-bet and EOMES, as well as surface receptors like NKG2D and KIR2D, and the cytokine IFNγ, displayed significant upregulation. A significant activation of NK cells was seen in the disease state. The levels of perforin and IFNγ were significantly elevated in the culture supernatants of patients. Additionally, a significantly higher cytotoxicity of NK cells in PV was observed. In lesioned tissues of PV, NK related markers were significantly increased. Lastly, we observed NK cells using confocal microscopy in the tissue biopsies of patients which showed significant infiltration of CD56+ CD3- NK cells at the lesional sites. This study aimed to shed light on the pivotal role of NK cells in the immunopathology of PV, offering a thorough understanding of their behaviour and changes in expression which might help in contributing to the development of novel therapeutics.

Immunostimulatory effects of Toll-like receptor ligands as adjuvants in establishing a novel mouse model for pemphigus vulgaris.

The meticulous selection of appropriate vaccine adjuvants is crucial for optimizing immune responses. Traditionally, pemphigus vulgaris (PV), an autoimmune disorder, has been modelled using complete Freund's adjuvant (CFA). In this study, we aimed to discern potential variations in immune responses elicited by Toll-like receptor (TLR) ligands as compared to CFA. A comprehensive investigation was conducted, comparing the effects of these adjuvants in conjunction with ovalbumin or desmoglein-3. Flow cytometry was employed to analyse distinct cell subsets, while enzyme-linked immunosorbent assay quantified antigen-specific antibodies and cytokine levels. Histological examination of harvested skin tissues and transcriptome analysis of skin lesions were performed to identify differentially expressed genes. TLR ligands demonstrated efficacy in inducing PV-like symptoms in wild-type mice, in contrast to CFA. This underscored the substantial impact of the adjuvant on self-antigen tolerance. Furthermore, we proposed an enhanced method for establishing a PV model through adoptive transfer, substituting CFA with TLR ligands. Our results revealed that in contrast to the perception that CFA being the most potent immunopotentiator reported, CFA promoted regulatory T cells (Treg), follicular regulatory T cells and IL-10-producing neutrophils, whereas TLR ligands downregulated CCL17 and IL-10. This suggested potential implications for the recruitment and activation of Treg subsets. While B cell and CD8+ T cell responses exhibited similarity, CFA induced less activation in dendritic cell subsets. A novel mouse model of PV and systemic comparison of immunostimulatory effects of adjuvants were provided by this study. The systematic comparison of CFA and TLR ligands shed light on the distinctive properties of these adjuvants, presenting innovative mouse models for the investigation of pemphigus. This study significantly contributes to adjuvant research and advances our understanding of PV pathogenesis. Immunization with desmoglein 3 and Toll-like receptor (TLR) ligands effectively induces pemphigus symptoms in wild-type mice, whereas complete Freund's adjuvant (CFA) fails. TLR ligands heightened the autoreactivity of donor cells in the adoptive transfer pemphigus model. CFA promoted regulatory T cells and IL-10-producing neutrophils, whereas TLR ligands downregulated CCL17 and IL-10, leading to more effective immune responses.

Beyond the skin: B cells in pemphigus vulgaris, tolerance and treatment.

Pemphigus vulgaris (PV) is a rare autoimmune bullous disease characterized by blistering of the skin and mucosa owing to the presence of autoantibodies against the desmosome proteins desmoglein 3 and occasionally in conjunction with desmoglein 1. Fundamental research into the pathogenesis of PV has revolutionized its treatment and outcome with rituximab, a B-cell-depleting therapy. The critical contribution of B cells to the pathogenesis of pemphigus is well accepted. However, the exact pathomechanism, mechanisms of onset, disease course and relapse remain unclear. In this narrative review, we provide an overview of the fundamental research progress that has unfolded over the past few centuries to give rise to current and emerging therapies. Furthermore, we summarize the multifaceted roles of B cells in PV, including their development, maturation and antibody activity. Finally, we explored how these various aspects of B-cell function contribute to disease pathogenesis and pave the way for innovative therapeutic interventions.

Single-Cell Transcriptomes and Immune Repertoires Reveal the Cell State and Molecular Changes in Pemphigus Vulgaris.

The etiology and pathogenesis of pemphigus vulgaris (PV) entail intricate interactions between immune cells and epithelial cells. However, the specific subtypes of immune cells involved in PV, along with their respective roles, remain elusive. Likewise, the precise functions and mechanisms by which glucocorticoids affect cell types within the disease context require further elucidation. To address these knowledge gaps, we performed 5' single-cell RNA sequencing, combined with V(D)J enrichment on buccal mucosal lesions and peripheral blood samples from treatment-naive patients with PV, in conjunction with post-treatment peripheral blood samples obtained after oral prednisone treatment. Our findings suggest that the IL-1α signaling pathway, myeloid APCs, inflammatory CD8+ resident memory T cells, and dysfunctional CD4+ regulatory T cells are involved in the pathogenesis of PV. Part of these findings were validated by immunohistochemical assays and multiplex immunofluorescence assays. Furthermore, our results highlight the significant impact of prednisone treatment on monocytes and mucosal-associated invariant T cells while revealing a limited effect on CD4+ regulatory T cells. Additionally, we present the CDR3 amino acid sequence of BCR related to PV disease and investigate the characteristics of TCR/BCR clonotypes. In conclusion, our study provides a comprehensive understanding of PV, particularly focusing on the mucosal-dominant type, and sheds light on the effects of glucocorticoids within the PV context. These insights hold promise for the development of new therapeutic strategies in this autoimmune disorder.

Serum Prolactin Concentration in Patients with Pemphigus Vulgaris

Background: Pemphigus vulgaris (PV) is an autoimmune bullous disorder characterized clinically by blisters and erosions of the skin and/or mucous membranes. Serum prolactin plays a role in the pathogenesis of pemphigus vulgaris. Objective: The study aims to observe the serum prolactin concentration in patients with pemphigus vulgaris. Methods: This cross-sectional study was conducted at the Department of Dermatology &amp; Venereology of Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh, between May 2017 and April 2018. A total of 35 patients were included in the study. A consecutive type of sampling technique was used. The dermatological examination was done to ascertain the extent of involvement of the disease. Results: Among 35 patients, 31.4% belonged to 30-50 years age group, while 62.9% belonged to &gt;50 years and 5.7% patients belonged to &lt;30 years ae group. The mean age was found 42.7±11.8 years with ranged from 19-65 years. The majority of the patients (57.1%) were male, and 42.9% patients were female. It was observed that 30(85.7%) had vesicles, 25(71.4%) had bulla, 35(100%) had erosions and 6(17.1%) had other types of lesions. 28 patients (80.0%) had scalp, 32(91.4%) had extremity, 35(100.0%) had trunk and 31(88.6%) had mucous membrane as the sites of involvement. The mean duration of disease was 9.0±12.7 months with a range from 0.5 to 36 months. It was observed that 9 patients (25.7%) had hyperprolactinemia, while 26 patients (74.3%) had normal levels of prolactin. The mean serum prolactin level was found 28.7±16.7 ng/ml with a range from 1.64 to 51.04 ng/ml. Conclusion: Since serum prolactin plays a role in the pathogenesis of pemphigus vulgaris, it may offer a novel therapeutic target for treatment of PV. Thus, we may reduce morbidity and mortality rate in PV patients by modifying their serum prolactin levels. Mugda Med Coll J. 2023; 6(1): 20-24

Type 2 T-Cell Responses against Distinct Epitopes of the Desmoglein 3 Ectodomain in Pemphigus Vulgaris

Pemphigus vulgaris (PV) is an autoimmune blistering disorder of the skin and/or mucous membranes caused by IgG autoantibodies that predominantly target two transmembrane desmosomal cadherins: desmoglein (DSG)1 and DSG3. DSG-specific T cells play a central role in PV pathogenesis because they provide help to autoreactive B cells for autoantibody production. In this study, we characterized DSG3-specific peripheral T cells in a cohort of 52 patients with PV and 41 healthy controls with regard to cytokine profile and epitope specificity. By ELISpot analysis, type 2 T cells reactive with the DSG3 ectodomain were significantly increased in patients with PV compared with those in healthy controls. By dextramer analysis, CD4+ T cells specific for an epitope within the extracellular domain of DSG3, DSG3(206-220), were found at significantly higher frequencies in patients with PV than in HLA-matched healthy controls. T-cell recognition of two distinct DSG3 epitopes, that is, DSG3(206-220) and DSG3(378-392), correlated significantly, suggesting a synergistic effect in B-cell help. Immunization of HLA-DRB1∗04:02-transgenic mice with PV with the same set of DSG3 peptides induced pathogenic DSG3-specific IgG antibodies, which induced loss of keratinocyte adhesion invitro. Thus, DSG3 peptide-specific T cells are of particular interest as surrogate markers of disease activity and potential therapeutic targets in PV.

Dominance and improved survivability of human γδT17 cell subset aggravates the immunopathogenesis of pemphigus vulgaris.

Human γδ T cells are highly enriched in epithelial cell-dominated compartments like skin. Nonetheless, their function in the pathogenesis of pemphigus vulgaris (PV), an autoimmune skin disorder, is lacking. Therefore, we investigated the functional expression of human γδT cell subsets along with their homing chemokine receptor-ligand and inflammatory cytokines in the immunopathogenesis of PV. Estimation of the frequency of γδT cell subsets by flow cytometry revealed four major subsets of γδ T cells (γδT1, γδT2, γδT17, γδTreg) in both control and PV circulation. The elevated frequency of γδT17 cells producing IL17 and expressing CCR6 receptor suggests their inflammatory and migratory potential in PV. In vitro culture of γδ T cells from patients showed increased mRNA expression of inflammatory cytokines IL17, RORγt, IL23, IL1, and co-stimulatory markers, CD27 and CD70. These findings correlated the role of IL1 and IL23 cytokines that alleviate the Th17 population in PV. Cytotoxic activities of γδ T cells were higher and inflammatory γδT17 cells were localized in the skin of PV whereas γδTreg cells associated TGFβ and FOXP3 were lowered. Hyperinflammatory phenotype of the γδT17 cell subset and its migratory potential might be aiding in the pathogenesis of PV, whereas γδTreg cells fail to suppress these inflammatory responses. Hence, γδT17 cell-associated markers can be targeted for identifying novel therapeutics in PV.

Detection of herpes simplex viruses in the oral lesions of patients with pemphigus vulgaris: Is it diagnostic or predictive of disease severity?

Some studies emphasise the relationship between the herpes simplex virus (HSV) and pemphigus. Although the possible role of HSV in the pathogenesis of pemphigus and the severity of the disease is obscure, we aimed to evaluate the presence of herpes simplex viruses (HSV 1/2) in the oral lesions of patients with pemphigus vulgaris and also assess its association with disease severity and types of lesions. A retrospective study was conducted on collected data in the form of collecting paraffin blocks, slides, and relevant pathology reports and referring to patients' medical records. A questionnaire containing details on the degree of skin, scalp, and mucosal involvement (Pemphigus Disease Area Index (PDAI)) was fulfiled. The immunoassay result was also collected to check the anti-desmoglein 3 and 1 antibodies (using ELISA technique). In this study, 52 patients of pemphigus vulgaris with oral lesions (case) and 52 patients with oral lesions not related to the disease (control) were evaluated. HSV1 was detected in 13.5% of oral pemphigus lesions and 1.9% of the control group (p=0.0598). There were no positive cases of HSV2 in either group. There was no significant association between the positivity of HSV1 and the site of lesions (p=1.00) or disease severity (p=0.28). However, we found a strong correlation between the PDAI disease severity score with the titre of the AntiDsg3 antibody (r=0.487, p=0.001) and AntiDsg1 antibody (r=0.309, p=0.026). This study demonstrated a significant prevalence of HSV1 in oral pemphigus lesions, and acyclovir therapy may play a significant role in managing these patients. However, HSV's role in the pathogenesis of pemphigus vulgaris cannot be clearly determined.

The dysregulation of circulating innate lymphoid cells is related to autoantibodies in pemphigus vulgaris.

Pemphigus vulgaris (PV) is a typical autoimmune disease caused by autoantibodies. Innate lymphoid cells (ILCs) are non-antigen-dependent populations composed of different subsets, also known as "mirror cells" of T cells, which play a crucial role in immune inflammatory diseases. However, the characteristics of ILCs in PV are unclear. Patients diagnosed with PV along with healthy controls in Second Xiangya Hospital of Central South University were studied. Flow cytometry was used to detect the proportion of ILC subsets in the peripheral blood. Anti-desmoglein (DSG) 1 and anti-DSG3 antibody levels of PV patients were detected. Thirty-eight PV patients and 37 healthy controls were enrolled. There were no differences in sex or age between the two groups. Compared with controls, ILCs/CD45+ lymphocytes were significantly decreased in patients with PV. The frequency of ILC1s increased in patients with PV and was positively correlated with anti-DSG3 antibodies. However, the frequency of ILC3s decreased in patients with PV and was negatively correlated with anti-DSG1 antibodies. After methylprednisolone treatment, ILC1/ILC levels significantly decreased. Circulating ILC subsets are associated with PV pathogenesis. Upregulated ILC1s seem to correlate positively with PV severity and can be restored after treatment.

The genetic basis of pemphigus vulgaris

AbstractThe severe autoimmune blistering disease pemphigus vulgaris (PV) is most probably mainly due to autoantibodies directed against desmosomal components of the epithelium, disrupting cell‐cell adhesion. The precise mechanisms underlying the development of the disease are still unknown, and immunosuppressive medications such as corticosteroids, which are linked to potentially serious adverse effects, are still the mainstay of treatment. Ethnic susceptibility and familial incidence hint to a genetic component to the pathophysiology of PV, which, if identified, could further improve our understanding of PV pathogenesis and lead to the discovery of new therapeutic targets for this potentially fatal condition. In this article, we review the evidence supporting a genetic component in PV and discuss the clinical and therapeutic implications of these discoveries.

Evaluation of E‐Cadherin Expression in Patients with Pemphigus Vulgaris via Immunohistochemistry

Pemphigus is a group of autoimmune bullous diseases that can affect the skin and mucous membranes, and it is vital to recognize the exact pathogenesis of this disease. This study aimed to investigate the role of E‐cadherin in the pathogenesis of pemphigus vulgaris (PV) and compare the expression of E‐cadherin in the lesions of PV patients with that in healthy individuals’ skin. Thirty tissue samples from histopathologically confirmed PV patients as the case group and 30 skin samples from healthy individuals as the control group were evaluated for E‐cadherin expression via the immunohistochemical method. Data analysis was performed using SPSS software version 25; chi‐squared and Fisher’s exact tests were used to examine the relationship between qualitative variables. Immunohistochemical staining revealed decreased E‐cadherin expression in the basal and suprabasal layers of the epidermis of PV patients compared with healthy individuals (P &lt; 0.001). E‐cadherin expression was 1+ in 53.3% of patients, 2+ in 40% of patients, and 3+ in only one (3.3%) patient. On the other hand, the expression of E‐cadherin in other layers of the epidermis was 1+ in one patient, 2+ in five patients (25%), and 3+ in 14 patients (70%). Also, the expression of E‐cadherin in all layers of the epidermis was 3+ in all controls. E‐cadherin expression in the basal and suprabasal layers of the epidermis appears to be lower in patients with PV compared with controls. Therefore, E‐cadherin immunohistochemical staining helps diagnose PV along with other diagnostic methods. Moreover, these findings may shed light on the role of E‐cadherin as a potential target for disease treatment aiming at disease stabilization. However, more studies are needed to clarify this issue.

ERK/MEK Pathway Regulates Th17 Cell Differentiation in Patients with Pemphigus Vulgaris.

T helper (Th) cells are involved in the pathogenesis of pemphigus vulgaris (PV). However, the mechanism still needs more exploration. This study aimed to evaluate the molecular mechanism of the dysregulation of Th17 cells in the peripheral blood of patients with PV. Serum levels of IL-17 and anti-Dsg3 titres in patients with PV were analysed using ELISA. The mRNA expression of retinoic acid orphan receptor γt (RORγt) in CD4+ T cells was detected using reverse transcription-quantitative PCR (qPCR). The number of Th17 cells was examined using flow cytometry. Western blot analysis and immunofluorescent staining were also performed to investigate the expression levels of ERK/MAPK signalling proteins and Th17 lineage-associated proteins. The proportion of Th17 cells and Th17 spectrum-associated proteins (p-STAT3, RORγt and IL-17) were upregulated in CD4+ cells in PV patients. The increased transcriptional levels of RORγt and IL-17 correlated positively with the severity of PV. Elevated phosphorylation of the ERK signalling factors was found in the collected CD4+ T cells in PV patients. The inhibition of the ERK signalling pathway significantly reduced the differentiation of Th17 cells in PV patients in vitro. Th17 cells are essential in the dysregulation of PV, and ERK signalling is involved in Th17-type immunity and promotes the development of PV. The study here provides us with a potential therapeutic target for PV.

Identification of Six microRNAs as Potential Biomarkers for Pemphigus Vulgaris: From Diagnosis to Pathogenesis.

Pemphigus vulgaris (PV) is a potentially fatal autoimmune bullous disease. The role of microRNA (miRNA, miR) in the diagnosis and pathogenesis of PV remains unknown. This study aims to provide potential miRNA biomarkers for PV diagnosis and therapy options. Serum samples were obtained from 22 PV patients, 15 mucous membrane pemphigoid (MMP) patients, and 10 normal controls (NC). Total RNA was extracted from the serum samples, and 12 selected miRNAs were detected by quantitative real-time polymerase chain reaction (qRT-PCR). Bioinformatic analyses including target gene prediction and enrichment analysis were performed. Twelve miRNAs were increased in the serum of the PV group compared with the NC group, in which six miRNAs had good efficacy to diagnose PV from MMP with the area under the receiver operator characteristic curves of 0.970 to 0.988. A series test for the combination of miR-584-5p and miR-155-5p reached the sensitivity and specificity of 95.5% and 100%. Bioinformatic analysis revealed target gene enrichment in the cell adhesion pathways, immune-relating pathways, and P38 mitogen-activated protein kinases signaling pathway. The study provides new insights and targets of miRNAs for the precise diagnosis and the exploration of pathogenesis for PV, which may serve as a reference for further research into autoimmune bullous diseases.

Detection of rare autoreactive T cell subsets in patients with pemphigus vulgaris.

Analysis of T lymphocyte proliferation and activation after antigenic or mitogenic stimulation is a vital parameter used in the diagnosis of various immuno-deficiencies and during the monitoring of treatment responses. Most applied techniques are based on the incorporation of tritiated thymidine (3H-TdR) or ELISPOT analysis, both rely on rather time-consuming/-intensive ex vivo protocols or encompass inherent drawbacks such as the inability to distinguish specific cell populations (3H-TdR, ELISPOT) or focus on a single cytokine (ELISPOT). Here we aimed at characterizing the rapid expression of intracellular CD154 (CD40L) as a marker for rare antigen-specific CD4+ T cells in pemphigus vulgaris (PV). Upon stimulation with human desmoglein (Dsg) 3, the major autoantigen in PV, the expression of CD154 was significantly increased in PV patients compared to healthy controls (HC) and correlated with anti-Dsg3 IgG titers. Patients with active disease showed higher numbers of Dsg3-reactive CD4+ T cells in CXCR5+ T follicular helper cells. In remittent PV and HC, CXCR5+CD4+ T cells remained largely unaffected by Dsg3. IL-17 and IL-21 expression were significantly induced only in CD154+CD4+ T cells from PV patients, lending themselves as potential novel treatment targets. Additionally, stimulation with immunodominant Dsg3-derived epitopes strongly induced a CD4+ T cell response via CD40-CD154 interaction similar to the human Dsg3 protein. We here established a rapid ex vivo assay allowing the detection of Dsg3-reactive CD4+ T cells from activated systemically available PBMCs, which further supports the crucial concept of antigen-specific T cells in the pathogenesis of PV.

Assessment of tissue E-cadherin and its proteolytic serum fragment in pemphigus vulgaris before and after remission: Acase-control study.

E-cadherin is a classic cadherin that mediates keratinocyte adhesion. To assess the tissue expression of E-cadherin and its proteolytic serum fragment (soluble E-cadherin) in pemphigus vulgaris (PV) before and after clinical remission compared with controls. Thirty-seven PV patients and thirty controls were enrolled. Pemphigus disease area index (PDAI) was calculated for patients at baseline and after remission. Punch biopsy specimens were taken from patients before, and after remission, and from controls for assessment of tissue E-cadherin by immunofluorescence. Similarly, serum samples were collected for assessment of serum soluble E-cadherin by ELISA. Presence, intensity, and mean intensity of tissue E-cadherin were significantly reduced in PV patients before treatment compared with controls (p< 0.001). Detected E-cadherin showed mainly a basal and suprabasal distribution with cell surface and a cytoplasmic expression. Serum E-cadherin was significantly higher in patients before treatment compared with controls (p= 0.006). With remission, tissue E-cadherin presence, intensity, mean intensity, and serum E-cadherin showed statistically significant improvement (p= 0.003, <0.001, <0.001, and 0.003 respectively). Tissue E-cadherin presence and serum E-cadherin level reached values equivalent to the controls (p= 0.49 and 0.44, respectively). Disruption of tissue E-cadherin and upregulation of serum soluble E-cadherin can contribute to the pathogenesis of PV. Clinical remission of PV is associated with normalization of tissue and serum E-cadherin.