Involvement of IL-17F via the induction of IL-6 in psoriasis

When recombinant proteins go wrong: The hidden pitfall of recombinant protein contamination

Recombinant proteins are critical tools in research; however, their purity is often assumed rather than verified, leading to potential experimental errors. This study aimed to investigate the inflammatory role of recombinant human IL-17F in dermal fibroblasts. Unexpectedly, we discovered with Western blot that recombinant IL-17F from the supplier was contaminated with IL-4, leading to unintended stimulatory effects such as STAT6 phosphorylation and gene induction of CCL26 and IL4R. This contamination led to misinterpretation of data, loss of research time, and erroneous conclusions about IL-17F activity. These findings underscore the critical need for stringent quality control in recombinant protein production and highlight the risks of relying on single-source suppliers. Researchers should remain cautious about potential contamination, ideally validating proteins from multiple suppliers. Our experience illustrates a broader requirement for suppliers to strengthen quality assurance measures, as contaminants can propagate misleading data in the literature and undermine research reproducibility.

Bimekizumab efficacy and safety in Korean patients with moderate to severe plaque psoriasis: A phase 3, randomized, placebo-controlled, double-blinded study

Bimekizumab treatment has demonstrated significant improvements in clinical outcomes in patients with moderate to severe plaque psoriasis; however, studies so far have focused on predominantly White patient populations from North America and Europe, with one smaller study in a Japanese population. Here, clinical responses, safety, and tolerability of bimekizumab treatment in Korean patients are reported. Korean patients with moderate to severe plaque psoriasis were randomized to bimekizumab 320 mg every 4 weeks (Q4W) or placebo Q4W to week 16. Co-primary efficacy end points were achievement of ≥90% improvement from baseline in the Psoriasis Area and Severity Index (PASI 90) and Investigator's Global Assessment score of 0/1 (clear/almost clear) at week 16. Secondary efficacy end points included achievement of PASI 75 at week 4 and Dermatology Life Quality Index 0/1 at week 16. Safety outcomes were also assessed. Statistical analysis of the co-primary efficacy end points was performed using a type I error rate, at a two-sided α level of 0.05. Overall, 47 Korean patients were randomized to treatment (bimekizumab: 32, placebo: 15). At week 16, bimekizumab-treated patients had significantly higher clinical responses versus placebo-treated patients (PASI 90: 81.3% vs. 0%; IGA 0/1: 87.5% vs. 0%, p < 0.001 for both). Bimekizumab showed a rapid onset of clinical response, with 75.0% of patients achieving PASI 75 by week 4 (0% in placebo patients [nominal p < 0.001]). A higher proportion of bimekizumab-treated patients achieved DLQI 0/1 at week 16 (46.9% vs. 6.7% in placebo patients, nominal p = 0.007), indicating greater improvements in health-related quality of life (HRQoL) following bimekizumab treatment. Bimekizumab was well-tolerated in Korean patients, with no new safety signals identified. Treatment with bimekizumab led to rapid improvements in clinical responses and HRQoL versus placebo in Korean patients, consistent with responses in global populations. These findings suggest that bimekizumab is an effective and well-tolerated treatment option in Korean patients with psoriasis.

Association of METS-IR index with psoriasis in US adults: a cross-sectional study

Psoriasis is linked to insulin resistance (IR). Nevertheless, the applicability of the METS-IR index, a new IR evaluation tool, for evaluating changes in insulin sensitivity in psoriasis populations is currently unknown. This study aimed to investigate the relationship between the METS-IR index and psoriasis in a US adult population. This cross-sectional study utilized data from adults aged 20 to 80 years from the U.S. National Health and Nutrition Examination Survey (NHANES) spanning 2003-2006 and 2009-2014. The associations between the METS-IR index and psoriasis were examined using multivariate logistic regression and smoothed curve fitting. Subgroup analyses and interaction tests were conducted to verify the stability of the association within the population. This study included 5,966 participants, of whom 182 had psoriasis. In the fully adjusted model, the METS-IR index was positively associated with psoriasis, showing a 1.7% increase in psoriasis prevalence for each one-unit increase in the METS-IR index (Model 2: OR 1.017, 95% CI 1.006-1.028). Participants in the highest quartile group were 91.9% more likely to develop psoriasis compared to those in the lowest quartile group (OR = 1.919, 95% CI 1.180-3.118). Smooth curve fitting revealed a nonlinear association between the METS-IR index and psoriasis, with an inflection point of 41.675. This positive association was more pronounced in females, non-obese individuals, those with light alcohol consumption, comorbid coronary heart disease and hyperlipidemia, non-hypertensive and non-diabetic individuals. The results of the study suggest that higher METS-IR scores are associated with an increased likelihood of psoriasis among U.S. adults. The METS-IR index is specifically recommended as a clinical indicator for the management and treatment of psoriasis in women, non-obese individuals, light alcohol consumers, individuals with comorbid coronary artery disease andhyperlipidemia, non-hypertensive and non-diabetic individuals. However, Considering the many known and unknown covariates that may be associated with psoriasis and influence theresults of the study, we remain cautious about the results obtained and look forward to the addition of subsequent studies.

Cytokines in psoriasis: From pathogenesis to targeted therapy

Psoriasis is a multifactorial disease that affects 0.84% of the global population and it can be associated with disabling comorbidities. As patients present with thick scaly lesions, psoriasis was long believed to be a disorder of keratinocytes. Psoriasis is now understood to be the outcome of the interaction between immunological and environmental factors in individuals with genetic predisposition. While it was initially thought to be solely mediated by cytokines of type-1 immunity, namely interferon-γ, interleukin-2, and interleukin-12 because it responds very well to cyclosporine, a reversible IL-2 inhibitor; the discovery of Th-17 cells advanced the understanding of the disease and helped the development of biological therapy. This article aims to provide a comprehensive review of the role of cytokines in psoriasis, highlighting areas of controversy and identifying the connection between cytokine imbalance and disease manifestations. It also presents the approved targeted treatments for psoriasis and those currently under investigation.

Association of IL-17F rs763780 polymorphism and risk of psoriasis in Turkish population: a case-control study

BACKGROUND

Psoriasis represents a chronic inflammatory phenotype shaped by genetic interactions, characterized by keratinocyte hyperproliferation and commonly affecting the skin and joints. Experimental and clinical studies suggest that the IL-17F gene locus plays a role as a central cytokine in the immunopathogenesis of psoriasis.

OBJECTIVES

Based on the central role of IL-17F in the pathogenesis of psoriasis, the authors thought that variations in this gene could affect the susceptibility and severity of this disease. Therefore, in this study, the authors aimed to analyze whether the IL-17F rs763780 variant has an effect on psoriasis pathogenesis in the Turkish population.

METHOD

In this case-control study, the study group consisted of 603 people (201 psoriasis patients (73 males/128 females)/402 controls (146 males/256 females) were genotyped in terms of IL-17F rs763780 polymorphism with TaqMan 5' Allelic Discrimination Test.

RESULTS

The genotype distributions of the IL-17F rs763780 polymorphism between patients and control groups were statistically different, and the TC (heterozygous genotype) and CC (homozygous mutant genotype) genotypes were more represented in the patients group than in the control group (24.9% vs. 10.2%; 2.0% vs. 0.2%, respectively). In addition, the variant C allele was higher in the patients group and this was statistically significant (p < 0.001), and the C allele carriage was associated with a 3.14-fold increased risk of psoriasis (95% CI 2.015‒24.921).

STUDY LIMITATIONS

The present study has some limitations. The first limitation is the relatively small sample size. The second limitation is that the authors could not measure IL-17F expression levels. However, the present study data draw attention to the importance of IL-17F which deserves to be studied in a larger sample group.

CONCLUSION

We report that IL-17F rs763780 TC and CC genotype and C allele are associated with an increased risk of psoriasis in the Turkish population.

Clostridium botulinum C3bot mediated effects on cytokine-induced psoriasis-like phenotype in full-thickness skin model

Clostridium botulinum C3 exoenzyme (C3bot) exclusively inhibits RhoA, B and C by ADP-ribosylation and is therefore used as a cell-permeable tool for investigating the cellular role of these Rho-GTPases. Rho-GTPases represent a molecular switch integrating different receptor signalling to downstream cascades including transcriptional cascades that regulate various cellular processes, such as regulation of actin cytoskeleton and cell proliferation. C3bot-induced inhibition of RhoA leads to reorganization of the actin cytoskeleton, morphological changes, and inhibition of cell proliferation as well as modulation of inflammatory response. In this study, we characterized the C3bot-mediated effects on a full-thickness skin model exhibiting a psoriasis-like phenotype through the addition of cytokines. Indeed, after the addition of cytokines, a decrease in epidermal thickness, parakeratosis, and induction of IL-6 was detected. In the next step, it was studied whether C3bot caused a reduction in the cytokine-induced psoriasis-like phenotypes. Basal addition of C3bot after cytokine induction of the full-thickness skin models caused less epidermal thinning and reduced IL-6 abundance. Simultaneous basal incubation with cytokines and C3bot, IL-6 abundance was inhibited, but epidermal thickness was only moderately affected. When C3bot was added apically to the skin model, IL-6 abundance was reduced, but no further effects on the psoriasis-like phenotype of the epidermis were observed. In summary, C3bot inhibits the cytokine-induced expression of IL-6 and thus may have an impact on the pro-inflammatory immune response in the psoriasis-like phenotype.

Interleukins and Psoriasis

Psoriasis is an immune-mediated chronic inflammatory skin disease that affects 2% to 3% of the world's population. It is widely assumed that immune cells and cytokines acting together play a crucial part in the pathophysiology of psoriasis by promoting the excessive proliferation of skin keratinocytes and inflammatory infiltration. Interleukins (ILs), as a critical component of cytokines, have been closely associated with the pathogenesis and progression of psoriasis. This review summarizes the current contribution of ILs to psoriasis and describes the role each IL performs in psoriasis. Furthermore, the paper presents the therapeutic effects and application prospects of biologics developed for ILs in clinical treatment and experiments. The study aims to further the research on ILs in the treatment of psoriasis.

Elevated serum IL-6 levels predict treatment interruption in patients with moderate to severe psoriasis: a 6-year real-world cohort study

BACKGROUND

Real-world, primary data on the treatment of psoriasis are scarce, especially concerning the role of soluble biomarkers as outcome predictors.

OBJECTIVE

The authors evaluated the utility of Th1/Th17 serum cytokines along with clinical characteristics as predictors of drug survival in the treatment of psoriasis.

METHODS

The authors consecutively included participants with moderate to severe psoriasis who were followed up for 6 years. Baseline interferon-α, tumor necrosis factor-α, and interleukin (IL)-2, IL-4, IL-6, IL-10, and IL-17A were measured using a cytometric bead array; clinical data were assessed. The authors calculated hazard ratios (HRs) for drug survival using a Cox proportional hazards model.

RESULTS

The authors included 262 patients, most of whom used systemic immunosuppressants or biologics. In the multivariate model, poor quality of life measured by the Dermatology Life Quality Index (HR = 1.04; 95% CI 1.01‒1.07; p = 0.012) and elevated baseline IL-6 (HR = 1.99; 95% CI 1.29‒3.08; p = 0.002) were associated with treatment interruption.

STUDY LIMITATIONS

The main limitation of any cohort study is the presence of confounders that could not be detected in clinical evaluation.

CONCLUSIONS

Poor quality of life and elevated baseline serum IL-6 level predicted treatment interruption in patients with moderate to severe psoriasis. Although IL-6 is not the most important mediator of the inflammatory pathway in the skin environment, it is an interesting biomarker candidate for predicting psoriasis treatment response.

Signaling pathways and targeted therapies for psoriasis

Psoriasis is a common, chronic, and inflammatory skin disease with a high burden on individuals, health systems, and society worldwide. With the immunological pathologies and pathogenesis of psoriasis becoming gradually revealed, the therapeutic approaches for this disease have gained revolutionary progress. Nevertheless, the mechanisms of less common forms of psoriasis remain elusive. Furthermore, severe adverse effects and the recurrence of disease upon treatment cessation should be noted and addressed during the treatment, which, however, has been rarely explored with the integration of preliminary findings. Therefore, it is crucial to have a comprehensive understanding of the mechanisms behind psoriasis pathogenesis, which might offer new insights for research and lead to more substantive progress in therapeutic approaches and expand clinical options for psoriasis treatment. In this review, we looked to briefly introduce the epidemiology, clinical subtypes, pathophysiology, and comorbidities of psoriasis and systematically discuss the signaling pathways involving extracellular cytokines and intracellular transmission, as well as the cross-talk between them. In the discussion, we also paid more attention to the potential metabolic and epigenetic mechanisms of psoriasis and the molecular mechanistic cascades related to its comorbidities. This review also outlined current treatment for psoriasis, especially targeted therapies and novel therapeutic strategies, as well as the potential mechanism of disease recurrence.

Cellular Mechanisms of Psoriasis Pathogenesis: A Systemic Review

Psoriasis is a common inflammatory skin disease characterized by abnormal proliferation of epidermal keratinocytes and massive infiltration of inflammatory cells. Many kinds of cells, including keratinocytes, T lymphocytes, dendritic cells, neutrophils, and macrophages, are reported to play critical roles in the pathogenesis and progression of psoriasis. However, to date, the role of each kind of cell in the pathogenesis and development of psoriasis has not been systematically reviewed. In addition, although antibodies developed targeting cytokines (e.g. IL-23, IL-17A, and TNF-α) released by these cells have shown promising results in the treatment of psoriasis patients, these targeted antibodies still do not cure psoriasis and only provide short-term relief of symptoms. Furthermore, long-term use of these antibodies has been reported to have adverse physical and psychological effects on psoriasis patients. Therefore, gaining a deeper understanding of the cellular and molecular pathogenesis of psoriasis and providing new thoughts on the development of psoriasis therapeutic drugs is of great necessity. In this review, we summarize the roles of various cells involved in psoriasis, aiming to provide new insights into the pathogenesis and development of psoriasis at the cellular level and hoping to provide new ideas for exploring new and effective psoriasis treatments.

Severe udder cleft dermatitis lesion transcriptomics points to an impaired skin barrier, defective wound repair and a dysregulated inflammatory response as key elements in the pathogenesis

This study is the first to investigate the transcriptomic changes occurring in severe udder cleft dermatitis lesions (UCD) in Holstein-Friesian cows. An examination of the gene expression levels in natural UCD lesions and healthy udder skin through RNA Seq-Technology provided a deeper insight into the inflammatory pathways associated with this disease. A clear distinction between the gene expression patterns of UCD lesions and healthy skin was shown in the principal component analysis. Genes coding for inflammatory molecules were upregulated such as the chemokines C-X-C motif ligand 2 (CXCL2), 5 (CXCL5) and 8 (CXCL8), and C-C motif ligand 11 (CCL11). Moreover, the genes coding for the multifunctional molecules ADAM12 and SLPI were amongst the highest upregulated ones, whereas the most downregulated genes included the ones coding for keratins and keratin-associated molecules. Predominantly inflammatory pathways such as the chemokine signaling, cytokine receptor interaction and IL-17 signaling pathway were significantly upregulated in the pathway analysis. These results point towards a fulminant, dysregulated inflammatory response concomitant with a disruption of the skin barrier integrity and a hampered wound repair mechanism in severe UCD lesions.

HS 3D-SeboSkin Model Enables the Preclinical Exploration of Therapeutic Candidates for Hidradenitis Suppurativa/Acne Inversa

Despite the rapid development in hidradenitis suppurativa (HS) research, the immediate introduction of potent therapeutic compounds in clinical trials and the lack of definitive outcome measures have led to the discontinuation of potential therapeutic compound studies. HS is a solely human disease, and therefore, the search for preclinical human models has been given priority. The 3D-SeboSkin model, a co-culture of human skin explants with human SZ95 sebocytes as a feeder layer, has been shown to prevent the rapid degeneration of human skin in culture and has been validated for HS preclinical studies. In this work, the HS 3D-SeboSkin model has been employed to characterize cellular and molecular effects of the EMA- and FDA-approved biologic adalimumab. Adalimumab, a tumor necrosis factor-α inhibitor, was shown to target inflammatory cells present in HS lesions, inducing a prominent anti-inflammatory response and contributing to tissue regeneration through a wound healing mechanism. Adalimumab inhibited the lesional tissue expression of TNF-α, IL-3, IL-15, and MCP-3 and downregulated the secretion of IL-1α, IL-5, RANTES, MCP-2, TNF-α, TNF-β, TGF-β, and IFN-γ. In contrast, IL-6 was stimulated. The compound failed to modify abnormal epithelial cell differentiation present in the HS lesions. Patients with Hurley stage II lesions exhibited stronger expression of autophagy proteins in perilesional than in lesional skin. Adalimumab modified the levels of the pro-apoptotic proteins LC3A, LC3B, and p62 in an individual, patient-dependent manner. Finally, adalimumab did not modify the NFκB signal proteins in SZ95 sebocytes and NHK-19 keratinocytes, used to study this specific pathway. The administration of the validated HS 3D-SeboSkin model in ex vivo studies prior to clinical trials could elucidate the individual pathogenetic targets of therapeutic candidates and, therefore, increase the success rates of clinical studies, minimizing HS drug development costs.

The interleukin-6 family in tissues is closely related to the clinical outcomes of oral lichen planus

OBJECTIVE

We attempted to investigate the role of interleukin-6 (IL-6) family expression in local tissues as it relates to presentations and outcomes in oral lichen planus (OLP), which is a common chronic inflammatory oral disease.

MATERIALS AND METHODS

A clinical follow-up cohort of OLP patients was established, and a biological sample library was constructed with categorization into erosive type (EOLP) and nonerosive type (NEOLP). Transcriptome sequencing of the lesions was then performed. A multiple regression model was used to explore the differences in IL-6 family expression among patients with different clinical types and clinical outcomes.

RESULTS

OLP tissue transcriptome sequencing showed that IL-6 family expression in EOLP increased significantly. It was also found that IL-6 family factors in the OLP recurrent erosion group were significantly increased compared to the persistent nonerosion group. Based on the multiple regression analysis of the OLP clinical cohort, it was found that the increased expression of the IL-6 family was closely related to the clinical types and clinical outcomes of OLP.

CONCLUSION

The high expression of the IL-6 family is closely related to the erosion of local mucosa and poor prognosis of OLP patients. IL-6-related factors may be used as therapeutic targets for OLP patients.

Continuous activation of the IL-17F driven inflammatory pathway in acute and chronic digital dermatitis lesions in dairy cattle

Objectives of the present study were to get a deeper insight into the course of the inflammatory pathways of digital dermatitis lesions in dairy cattle by investigating the gene expression patterns throughout the different clinical stages (M0 to M4.1) of the disease. Normal skin samples (M0) were used as a reference for comparing the gene expression levels in the other M-stages through RNA Seq-technology. Principal component analysis revealed a distinct gene expression pattern associated with digital dermatitis lesions in comparison to healthy skin with a further clustering of the acute M1, M2 and M4.1 stages versus the chronic M3 and M4 stages. The majority of the up-and downregulated genes in the acute and chronic stages can be placed into a common 'core' set of genes involved in inflammation, such as A2ML1, PI3, CCL11 and elafin-like protein, whereas the most downregulated genes included keratins and anti-inflammatory molecules such as SCGB1D and MGC151921. Pathway analysis indicated the activation of the pro-inflammatory IL-17 signaling pathway in all the M stages through the upregulation of IL-17F. These results indicate that digital dermatitis is associated with an excessive inflammatory immune response concomitant with a disrupted skin barrier and impaired wound repair mechanism. Importantly, despite their macroscopically healed appearance, a significant inflammatory response (Padj < 0.05) was still measurable in the M3 and M4 lesions, potentially explaining the frequent re-activation of such lesions.

Orchestrated Cytokines Mediated by Biologics in Psoriasis and Its Mechanisms of Action

Psoriasis is an autoimmune disease mediated by disturbed T cells and other immune cells, and is defined by deep-red, well-demarcated skin lesions. Due to its varied etiologies and indefinite standard pathogenesis, it is challenging to consider the right treatment exclusively for each psoriasis patient; thus, researchers yearn to seek even more precise treatments other than topical treatment and systemic therapy. Using biologics to target specific immune components, such as upregulated cytokines secreted by activated immune cells, is the most advanced therapy for psoriasis to date. By inhibiting the appropriate pro-inflammatory cytokines, cellular signaling can be altered and, thus, can inhibit further downstream inflammatory pathways. Herein, the roles of cytokines with their mechanisms of action in progressing psoriasis and how the usage of biologics alleviates cellular inflammation are discussed. In addition, other potential pro-inflammatory cytokines, with their mechanism of action, are presented herein. The authors hope that this gathered information may benefit future research in expanding the discovery of targeted psoriasis therapy.

Dihydroartemisinin Alleviates Imiquimod-Induced Psoriasis-like Skin Lesion in Mice Involving Modulation of IL-23/Th17 Axis

Background: Psoriasis is a T help 17 (Th17) cell-mediated chronic inflammatory skin disease. Recent studies have shown that dihydroartemisinin (DHA) can significantly reduce experimental autoimmune encephalomyelitis and rheumatoid arthritis by regulating Th17 cells.

Objective: To verify whether DHA can improve the symptoms of psoriasis and to further explore the possible mechanism.

Methods: The efficiency of DHA was preliminary detected on human keratinocytes (HaCaT) cells in psoriatic condition. Then, imiquimod-induced psoriasis-like model in BALB/c mice was established to evaluate the effects of DHA in vivo.

Results: Under the stimulation of tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ), DHA inhibited the proliferation of HaCaT cells and significantly affected the mRNA expression levels of IFN-γ, interleukin (IL), IL-17A and IL-23. DHA treatment reduced the severity of psoriasis-like skin and resulted in less infiltration of immune cells in skin lesions. DHA restored the expression of IFN-γ, IL-17A, and IL-23 in skins, as well as a decrease of cytokines and chemokines in skin supernatant. DHA also altered the cellular composition in the spleen, which is the makeup of the T cells, dendritic cells (DCs), and macrophages. DHA recovered Th17-related profile with decreased frequency of IL-17⁺CD4⁺T cells from splenocyte of mice. Furthermore, DHA also inhibited the concentration of IL-17 from Th17 cells and the expression of Th17 cell-related transcription factors retinoid-related orphan receptor-gamma t (ROR-γt) in vitro. In addition, phosphorylation of signal transducer and activator of transcription-3 (STAT3) was significantly reduced in DHA treatment mice, suggesting that the IL-23/Th17 axis plays a pivotal role.

Conclusion: DHA inhibits the progression of psoriasis by regulating IL-23/Th17 axis and is expected to be an effective drug for the treatment of psoriasis.

E3 ubiquitin ligase NEDD4L negatively regulates keratinocyte hyperplasia by promoting GP130 degradation

Psoriasis is mainly characterized by abnormal hyperplasia of keratinocytes and immune cells infiltrating into the dermis and epidermis. Neural precursor cell expressed developmentally downregulated 4-like (NEDD4L) is a highly conserved HECT type E3 ligase that plays an important role in regulating physiological and pathological processes. Here, we identify NEDD4L as a negative regulator of psoriasis. Nedd4l significantly inhibits imiquimod (IMQ)-induced skin hyperplasia, and this effect is attributed to the inhibitory effect of NEDD4L on IL-6/GP130 signaling in keratinocytes. Mechanistically, NEDD4L directly interacts with GP130 and mediates its Lys-27-linked ubiquitination and proteasomal degradation. Moreover, the expression of NEDD4L is downregulated in the epidermis from IMQ-treated mice and psoriasis patients and negatively correlates with the protein levels of GP130 and p-STAT3 in clinical samples. Collectively, we uncover an inhibitory role of NEDD4L in the pathogenesis of psoriasis and suggest a new therapeutic strategy for the treatment of psoriasis.

Application of imiquimod-induced murine psoriasis model in evaluating interleukin-17A antagonist

BACKGROUND

Interleukin-17A (IL17A) is a proinflammatory cytokine critically involved in autoimmune diseases, and monoclonal antibodies of IL17A have been approved for clinical treatment of psoriasis. However, a usable psoriatic animal model has been always required for preclinical evaluation of IL17A antagonists. Imiquimod (IMQ)-induced psoriasis model is widely used in fundamental research, but it's not able to accurately show anti-psoriatic effect of IL17A antagonists with conventional modelling condition.

RESULTS

On female C57BL/6 mice, with optimization on the usage of IMQ, positive control reagent and anti-mIL17A antibody, a 7-day model with proper testing window, acceptable disease severity as well as high repeatability was developed, and the efficacy of IL17A antagonist can be objectively evaluated by several qualitative and quantitative indices. Meanwhile, we validated the detailed involvement of IL17A signaling in disease progression, confirmed that the expression levels of IL17A and its related cytokines were induced by IMQ application, and its downstream cytokines can be inhibited by IL17A antagonist treatment. In further study, we revealed that IL17A was transient induced by IMQ and directly caused downstream signaling activation. This finding on the kinetical change of IL17A signaling will manifest the pharmacokinetics-pharmacodynamics investigation of IL17A antagonists.

CONCLUSIONS

Our work presents the application of a convenient psoriatic animal model in the research and development of IL17A antagonists, meanwhile providing extra evidence for understanding IL17A's role in the progression of IMQ-induced psoriasis model, which manifest the research and development of IL17A antagonists.

Interleukin 22 and 6 serum concentrations decrease under long-term biologic therapy in psoriasis

Introduction

Psoriasis, affecting approximately 2% of the worldwide population, is a chronic, inflammatory skin disease in which overexpression of proinflammatory cytokines is observed. Most of the available data on the influence of antipsoriatic therapy on the cytokine serum concentration are inconsistent and based on short-term observations.

Aim

To evaluate the influence of long-term biologic therapy with tumor necrosis factor α (TNF-α) blockers (adalimumab, etanercept, infliximab) and IL-12/23 inhibitor (ustekinumab) on the level of IL-6, IL-22 in the sera of patients with psoriasis.

Material and methods

Blood samples were collected from 42 psoriatic patients in order to determine IL-6 and IL-22 serum concentrations prior to and at the 3^rd, 12^th, 24^th and 36^th month of biologic therapy. Psoriasis Activity and Severity Index (PASI) was assessed at the same time points. The control group consisted of 30 sex- and age-matched healthy volunteers.

Results

Mean PASI index at baseline was 14.49 ±3.69 and decreased significantly until the end of the observation. Mean IL-6 serum concentration decreased significantly in all study groups (p < 0.05). A statistically significant decrease in IL-22 concentrations was demonstrated during the treatment with adalimumab and infliximab but not etanercept or ustekinumab.

Conclusions

According to obtained results, IL-6 and IL-22 serum concentration may be an accurate marker of response to antipsoriatic therapy, even though not correlated with PASI index. Biologic therapy in psoriasis allows for long-term clinical improvement expressed not only by the remission of skin lesions, but also by lowering serum concentrations of pro-inflammatory interleukins.

The role of Th17 cells in psoriasis

T helper 17 (Th17) cells have been involved in the pathogenesis of many autoimmune and inflammatory diseases, like psoriasis, multiple sclerosis (MS), rheumatoid arthritis (RA), and inflammatory bowel disease (IBD). However, the role of Th17 cells in psoriasis has not been clarified completely. Th17-derived proinflammatory cytokines including IL-17A, IL-17F, IL-21, IL-22, and IL-26 have a critical role in the pathogenesis of these disorders. In this review, we introduced the signaling and transcriptional regulation of Th17 cells. And then, we demonstrate the immunopathology role of Th17 cells and functions of the related cytokines in the psoriasis to get a better understanding of the inflammatory mechanisms mediated by Th17 cells in this disease.

Association of Pathogenic Th17 Cells with the Disease Severity and Its Potential Implication for Biological Treatment Selection in Psoriasis Patients

Psoriasis is an inflammatory autoimmune disease characterized by cutaneous lesions in plaques. It has been proposed that the immune response has a key role in the disease progression. Particularly, the Th17 cells through IL-17 can contribute to maintain the inflammatory process. The pathogenic Th17 phenotype has been described in human diseases and associated with high severity in inflammatory experimental models. However, it is not clear if the pathogenic phenotype could be present in the skin and peripheral blood as well as its possible association to severity in psoriasis. In the lesional skin, we found high infiltration of Th17 cells and the pathogenic phenotype, finding a correlation between the frequency of Th17 cells and the Psoriasis Area and Severity Index (PASI) score. In peripheral blood, we observed a pool of Th17 lymphocytes with potential to acquire pathogenic features. Interestingly, the percentage of pathogenic Th17 cells (CD4⁺ RORγt⁺ IFN-γ⁺) correlates with disease severity. Moreover, we distinguished three groups of patients based on their IL-17/IFN-γ production by Th17 lymphocytes, which seems to be related with a dynamic or stable potential to express these cytokines. Remarkably, we evaluated the cytokine production by Th17 cells as an immunological marker for the adequate selection of biologic therapy. We found that patients analyzed by this immunological approach and treated with antibodies against IL-17 and TNFα showed great improvement depicted by reduction in PASI and Dermatology Life Quality Index (DLQI) score as well as the percentage of Body Surface Area (BSA). Altogether, our results highlight the importance of the assessment of the pathogenic phenotype in Th17 cells as an immune personalized analysis with the potential to support the therapy choice in the clinical practice.

IL-17 in inflammatory skin diseases psoriasis and hidradenitis suppurativa

The skin is one of the most important organs in the body, providing integrity and acting as a barrier to exclude microbes, allergens and chemicals. However, chronic skin inflammation can result when barrier function is defective and immune responses are dysregulated or misdirected against harmless or self-antigens. During the last 15 years interleukin (IL)-17 cytokines have emerged as key players in multiple inflammatory disorders, and they appear to be especially prominent in skin inflammation. IL-17 cytokines produced by T cells and other cell types potently activate keratinocytes to promote inflammation in a feed-forward loop. Given this key pathogenic role of the IL-17 pathway in autoimmune and inflammatory disease, it has been the focus of intense efforts to target therapeutically. The inflammatory effects of IL-17 can be targeted directly by blocking the cytokine or its receptor, or indirectly by blocking cytokines upstream of IL-17-producing cells. Psoriasis has been the major success story for anti-IL-17 drugs, where they have proven more effective than in other indications. Hidradenitis suppurativa (HS) is another inflammatory skin disease which, despite carrying a higher burden than psoriasis, is poorly recognized and under-diagnosed, and current treatment options are inadequate. Recently, a key role for the IL-17 pathway in the pathogenesis of HS has emerged, prompting clinical trials with a variety of IL-17 inhibitors. In this review, we discuss the roles of IL-17A, IL-17F and IL-17C in psoriasis and HS and the strategies taken to target the IL-17 pathway therapeutically.

Interventions for chronic palmoplantar pustulosis

BACKGROUND

Palmoplantar pustulosis is a chronic inflammatory disease in which sterile, relapsing pustules appear on the palms and soles, possibly in conjunction with other symptoms. The previous Cochrane Review on this topic was published in 2006, before biological treatments were extensively used.

OBJECTIVES

To assess the effects of interventions for chronic palmoplantar pustulosis to induce and maintain complete remission.

SEARCH METHODS

We searched the following databases up to March 2019: Cochrane Skin Specialised Register, CENTRAL, MEDLINE, Embase, and LILACS. We also searched five trials registers and checked the reference lists of the included studies for further references to relevant randomised controlled trials (RCTs).

SELECTION CRITERIA

We considered RCTs including people with palmoplantar pustulosis or chronic palmoplantar pustular psoriasis assessing topical therapy, systemic therapy, combinations of topical or systemic therapies, or non-pharmacological therapies compared with placebo, no intervention, or each other.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Our outcomes included 'Proportion of participants cleared or almost cleared', 'Proportion of participants with adverse effects serious or severe enough to cause withdrawal', 'Proportion of participants with at least 50% improvement in disease severity', and 'Proportion of participants with adverse effects'.

MAIN RESULTS

We included 37 studies (1663 participants; mean age 50 years (range 34 to 63); 24% males). These studies reported condition severity differently. Around half of the included trials stated the setting (hospitals, community clinics, or both). More than half of the studies were at high risk of bias in at least one domain. Our included studies assessed mainly systemic treatments (retinoids, ciclosporin, biologics, etretinate + PUVA (combination of psoralens and long-wave ultraviolet radiation) therapy combined, and antibiotics), but also topical treatments (dermocorticoids, vitamin D) and phototherapy (PUVA, ultraviolet A1 (UVA1)). Other interventions were assessed by single studies. The most common comparator was placebo. All results presented in this abstract were assessed in the short term (mean treatment duration was 11 weeks (range 8 to 24 weeks)) and are based on participants with chronic palmoplantar pustulosis. All outcome time point measurements were taken from baseline and assessed at the end of treatment. Short-term and long-term outcomes were defined as measurement up to 24 weeks after randomisation and between 24 and 104 weeks after randomisation, respectively. One trial (188 participants) assessed the topical vitamin D derivative maxacalcitol versus placebo and found that maxacalcitol may be more effective than placebo in achieving clearance (risk ratio (RR) 7.83, 95% confidence interval (CI) 1.85 to 33.12; low-quality evidence), and the risk of adverse effects (such as mild local irritation, pruritus, and haematological or urinary test abnormalities) is probably similar in both groups (RR 0.87, 95% CI 0.64 to 1.19; moderate-quality evidence). Severity was not reported. Two trials (49 participants) assessed PUVA therapy versus placebo or no treatment, providing very low-quality evidence. Adverse effects were reported with oral PUVA (including nausea, ankle swelling, and non-purulent conjunctivitis) and with local PUVA (including blistering, erythema, and pruritus). With regard to the systemic retinoid alitretinoin, one trial (33 participants; moderate-quality evidence) showed that alitretinoin probably makes little or no difference in reducing severity when compared to placebo (RR 0.69, 95% CI 0.36 to 1.30). A similar number of adverse events were reported in both treatment groups, including headache, cheilitis, nausea, arthralgia, and nasopharyngitis (RR 0.84, 95% CI 0.61 to 1.17). Clearance was not reported. There may be little or no difference between etanercept and placebo in achieving clearance (RR 1.64, 95% CI 0.08 to 34.28; 1 study; 15 participants; low-quality evidence); however, the 95% CI was very wide, showing there may be a difference between groups. Severity was not measured. More patients treated with placebo may achieve reduced severity than those treated with ustekinumab, but the wide 95% CI indicates there might be little or no difference between groups and there might be greater effect with ustekinumab (RR 0.48, 95% CI 0.11 to 2.13; 1 study; 33 participants; low-quality evidence). Clearance was not reported. It is uncertain whether guselkumab increases clearance when compared to placebo (2 studies; 154 participants) because the quality of evidence is very low, but guselkumab probably better reduces disease severity (RR 2.88, 95% CI 1.24 to 6.69; 1 study; 49 participants; moderate-quality evidence). Secukinumab is probably superior to placebo in reducing severity (RR 1.55, 95% CI 1.02 to 2.35; 1 study; 157 participants; moderate-quality evidence), but our clearance outcome was not reported. None of these trials reported on occurrence of adverse effects. Only two of the studies discussed above reported adverse effects serious or severe enough to cause withdrawal. Guselkumab may cause more serious adverse events when compared to placebo, but there is uncertainty due to the very wide 95% CI showing there may be little or no difference and showing more events with placebo (RR 2.88, 95% CI 0.32 to 25.80; 1 study; 49 participants; low-quality evidence). Secukinumab probably causes more serious adverse events than placebo (RR 3.29, 95% CI 1.40 to 7.75; 1 study; 157 participants; moderate-quality evidence).

AUTHORS' CONCLUSIONS

Evidence is lacking for major chronic palmoplantar pustulosis treatments such as superpotent corticosteroids, phototherapy, acitretin, methotrexate, and ciclosporin. Risk of bias and imprecision limit our confidence. Maxacalcitol may be more effective than placebo in achieving clearance in the short term (low-quality evidence), and the risk of adverse effects is probably similar (moderate-quality evidence). Oral alitretinoin is probably no more effective than placebo in reducing severity, with a similar risk of adverse effects (moderate-quality evidence). Regarding biological treatments, we are uncertain of the effect of etanercept on clearance and the effect of ustekinumab on severity (low-quality evidence). Secukinumab and guselkumab are probably superior to placebo in reducing severity (moderate-quality evidence). Adverse events not requiring withdrawal were not reported for these treatments. Reporting of serious adverse effects was incomplete: compared to placebo, secukinumab probably caused more participant withdrawals (moderate-quality evidence), but we are uncertain of the effect of guselkumab (low-quality evidence). Future trials should assess commonly used treatments using validated severity and quality of life scales.

Measurement of squamous cell carcinoma antigen 2 in lichen planus patients

BACKGROUND

Lichen planus (LP) is an autoinflammatory mucocutaneous skin disorder with a multifactorial pathogenesis. Squamous cell carcinoma antigen (SCCA) is a tumor marker recognized as a part of the ovalbumin-serpin family. In patients' serum and skin, SCCA expression is increased with inflammatory skin diseases as psoriasis.

AIM

This study aimed to estimate serum SCCA2 levels in patients with LP and to assess its relationship with disease severity and types.

PATIENTS AND METHODS

We included 34 adult patients with LP and 20 healthy adults as control. The total score of LP activity, area, and severity index was calculated for all patients, whereas serum SCCA2 levels were measured in all participants using enzyme-linked immunosorbent assay.

RESULTS

The mean serum SCCA2 levels were significantly higher in patients than their healthy controls (P < .001) and in female patients than male patients (P < .01). The mean serum SCCA2 levels in patients with eruptive LP were significantly higher compared to those with localized (P < .05) and hypertrophic (P < .01) forms. In ROC analysis, when LPAASI = 5 was taken as the limit, an ideal SCCA2 endpoint was discovered at 0.45 ng/mL with the upper Youden index.

CONCLUSION

Serum SCCA2 might be a potential biomarker for LP as it was elevated in patients with LP and was associated with disease severity. Further studies are needed to assess the therapeutic effect of its blockade, which could be a way to improve outcome in LP patients.

Evaluation of The Expression Levels of Three Long Non-Coding RNAs in Multiple Sclerosis

Objective

Multiple sclerosis (MS) is a chronic disorder involving both inflammatory and neurodegenerative responses. Long non-coding RNAs (lncRNAs) have been had an emerging role as the biomarkers of different disorders, including autoimmune diseases. Previous studies have shown that NR_003531.3 (MEG3a), AC000061.1_201, and AC007182.6 play a role in the pathogenesis of human autoimmune diseases. However, the potential significance of these lncRNAs, as the diagnostic biomarkers of MS, has not been studied yet. We aimed to quantitatively evaluate the expression levels of NR_003531.3, AC000061.1_201, and AC007182.6 in peripheral blood samples of MS patients in comparison with healthy controls.

Materials and Methods

In this case-control study, the blood samples from 20 MS patients and 10 healthy controls were collected. Total RNA was extracted, and the expression levels of three selected lncRNAs were quantitatively measured using the quantitative real time-polymerase chain reaction (qRT-PCR) method.

Results

We detected a significant down-regulation in the expression of NR_003531.3 in MS patients, while no marked changes were observed in the expression of AC000061.1_201 and AC007182.6 in patients compared with controls. Based on the receiver operating characteristic (ROC) curve analysis, NR_003531.3 could discriminate MS patients from healthy subjects effectively. Regarding the prognosis of MS patients, NR_003531.3 is significantly and inversely correlated with the expanded disability status scale (EDSS).

Conclusion

The potential role of NR_003531.3 lncRNA as a diagnostic biomarker to distinguish MS patients is proposed. Prognostically, NR_003531.3 correlates with lower disability rates in MS patients.

Psoriasis: Association of interleukin-17 gene polymorphisms with severity and response to treatment

Psoriasis is a chronic, inflammatory disease with a complex pathogenesis that is not yet fully understood. Although it is a multifactorial disease, the genetic factor has a major role in the pathogenesis of psoriasis. Genome wide association studies have identified over 50 genetic loci associated with psoriasis risk. Beside TNF-α or IL-23, the IL-17 family is a newer group that has proven implications in the pathogenesis of psoriasis. The most important members of the family, with pro-inflammatory qualities, are IL-17A and IL-17F. These interleukins are produced by a varied number of cells, but by far the most important are Th17 cells. Of the patients 20-30% present moderate-to-severe psoriasis, therefore, systemic medication (phototherapy, methotrexate, cyclosporine, acitretin or biologic agents) is mandatory. The necessity of an individualized treatment plan, for each patient, is imperative in order to establish the best strategy for non-responders to classical treatment or to other biologic treatments. The discovery of Th17 pathway improved the treatment and prognosis of psoriasis. Anti-psoriatic agents against IL-17 or its receptors are a novel group of biologic agents; these include ixekizumab, secukinumab and brodalumab. Polymorphisms of IL-17 family have been correlated with the severity and response to treatment in psoriasis, and also with the risk of inflammatory, infectious, autoimmune or neoplastic pathologies. The significant difference in the presence or absence of susceptibility loci in different population is due to genetic background and environmental factors that have a major impact on disease predisposition. In this study, we reviewed the importance and influence of the IL-17 polymorphisms as predictors of response to treatment and severity of the disease.

Infiltration of T Cells into a Three-Dimensional Psoriatic Skin Model Mimics Pathological Key Features

Psoriasis is an autoimmune chronic dermatosis that is T cell-mediated, characterized by epidermal thickening, aberrant epidermal differentiation and inflammatory infiltrates, with a dominant Th1 and Th17 profile. Additional in vitro models are required to study the complex interactions between activated T cells and skin cells, and to develop new, more effective treatments. We have therefore sought to model this psoriatic inflammation by the generation of tissue-engineered immunocompetent tissues, and we have investigated the response of activated T-cell infiltration in models produced with lesional psoriatic skin cells on major hallmarks of psoriasis. The immunocompetent lesional skin model displayed a delayed onset of epidermal differentiation, an hyperproliferation of the basal keratinocytes, a drastic increase in the secretion of proinflammatory cytokines, and a disturbed expression of key transcription factors, as observed in lesional plaques, suggesting a crucial importance of combining the pathological phenotype of cutaneous cells to T cells in order to generate a relevant model for psoriasis. Finally, we found this skin model to be responsive to methotrexate treatment, making it a valuable tool for drug development.

A randomized, double-blind, placebo-controlled phase 1 study of multiple ascending doses of subcutaneous M1095, an anti-interleukin 17A/F nanobody, in moderate-to-severe psoriasis

BACKGROUND

Interleukin 17 is involved in the pathogenesis of psoriasis, a chronic debilitating disease.

OBJECTIVES

To evaluate the safety/tolerability, immunogenicity, pharmacokinetics/pharmacodynamics, and efficacy of M1095, an anti-interleukin 17A/F nanobody, in moderate-to-severe plaque psoriasis.

METHODS

This multicenter, double-blind, placebo-controlled dose escalation phase 1 study randomized 44 patients 4:1 to treatment with subcutaneous M1095 (30, 60, 120, or 240 mg) or placebo biweekly for 6 weeks, in 4 ascending dose cohorts.

RESULTS

The most frequent treatment-emergent adverse events with M1095 were pruritus (n = 4) and headache (n = 3); 2 patients withdrew owing to adverse events (injection site reaction and elevated liver enzyme levels). The terminal half-life of M1095 was 11 to 12 days. The area under the curve/maximum concentration was dose proportional. Of 10 M1095-treated patients positive for antidrug antibodies, 5 showed treatment-emergent antidrug antibody responses. There was no effect on M1095 exposure. Marked decreases in psoriasis inflammatory markers were observed with M1095. By day 85, 100% and 56% of patients receiving M1095, 240 mg, achieved psoriasis area and severity index 90 and 100, respectively. Improvements in static Physician's Global Assessment and affected body surface area were also seen.

LIMITATIONS

Interpretation of efficacy data is limited by the small sample size.

CONCLUSION

Multiple subcutaneous doses of M1095 showed a favorable safety profile with dose-dependent improvements in psoriasis.

Unmet Needs in the Field of Psoriasis: Pathogenesis and Treatment

In times of targeted therapies, innovative therapeutics become tools to further unravel the pathogenesis of the treated disease, thus influencing current pathogenetic concepts. Based on such paradigm shifts, the next generation of novel therapeutic targets might be identified. Psoriasis is a good example for the resulting most fruitful dialog between clinical and fundamental research. As a result of this, the key role of Th17 lymphocytes, some of their effector molecules, as well as mediators contributing to their maturation have been identified, many of these being targeted by some of the most effective drugs currently available to treat psoriasis. During this process, it became obvious that major parts of the puzzle remain yet to be uncovered or understood in much more detail. This review will therefore address the search for additional important effector cells other than Th17 lymphocytes, such as neutrophils, monocytes, and mast cells, mediators other than IL-17A, including some other IL-17 isoforms, and trigger factors such as potential autoantigens. This will lead to discussing the next generation of targeted therapies for psoriasis as well as treatment goals. These goals need to comprise both psoriasis as well as its comorbidities, as a comprehensive approach to manage the whole patient with all his health issues is urgently needed. Finally, given the substantial differences in resources available in different parts of the world, the global burden of psoriasis and options on how to care for patients outside developed countries will be assessed.

Caspase 1/11 Deficiency or Pharmacological Inhibition Mitigates Psoriasis-Like Phenotype in Mice

Inflammatory caspases, activated within the inflammasome, are responsible for the maturation and secretion of IL-1β/IL-18. Although their expression in psoriasis was shown several years ago, little is known about the role of inflammatory caspases in the context of psoriasis. Here, we confirmed that caspases 1, 4, and 5 are activated in lesional skin from psoriasis patients. We showed in three psoriasis-like models that inflammatory caspases are activated, and accordingly, caspase 1/11 invalidation or pharmacological inhibition by Ac-YVAD-CMK (i.e., Ac-Tyr-Val-Ala-Asp-chloromethylketone) injection induced a decrease in ear thickness, erythema, scaling, inflammatory cytokine expression, and immune cell infiltration in mice. We observed that keratinocytes were primed to secrete IL-1β when cultured in conditions mimicking psoriasis. Generation of chimeric mice by bone marrow transplantation was carried out to decipher the respective contribution of keratinocytes and/or immune cells in the activation of inflammatory caspases during psoriasis-like inflammatory response. Our data showed that the presence of caspase 1/11 in the immune system is sufficient for a fully inflammatory response, whereas the absence of caspase 1/11 in keratinocytes/fibroblasts had no impact. In summary, our study indicates that inflammatory caspases activated in immune cells are implicated in psoriasis pathogenesis.

The IL-17 Family of Cytokines in Psoriasis: IL-17A and Beyond

Psoriasis is a frequent chronic inflammatory skin disease, nowadays considered a major global health problem. Several new drugs, targeting the IL-23/IL-17A pathway, have been recently licensed or are in clinical development. These therapies represent a major improvement of the way in which psoriasis is managed, since they show an unprecedented efficacy on skin symptoms of psoriasis. This has been made possible, thanks to an increasingly more accurate pathogenic view of psoriasis. Today, the belief that Th17 cells mediate psoriasis is moving to the concept of psoriasis as an IL-17A-driven disease. New questions arise at the horizon, given that IL-17A is part of a newly described family of cytokines, which has five distinct homologous: IL-17B, IL-17C, IL-17D, IL-17E, also known as IL-25 and IL-17F. IL-17 family cytokines elicit similar effects in target cells, but simultaneously trigger different and sometimes opposite functions in a tissue-specific manner. This is complicated by the fact that IL-17 cytokines show a high capacity of synergisms with other inflammatory stimuli. In this review, we will summarize the current knowledge around the cytokines belonging to the IL-17 family in relation to skin inflammation in general and psoriasis in particular, and discuss possible clinical implications. A comprehensive understanding of the different roles played by the IL-17 cytokines is crucial to appreciate current and developing therapies and to allow an effective pathogenesis- and mechanisms-driven drug design.

Serum Squamous Cell Carcinoma Antigen in Psoriasis: A Potential Quantitative Biomarker for Disease Severity

BACKGROUND

An objective and quantitative method to evaluate psoriasis severity is important for practice and research in the precision care of psoriasis.

OBJECTIVES

We aimed to explore serum biomarkers quantitatively in association with disease severity and treatment response in psoriasis patients, with serum squamous cell carcinoma antigen (SCCA) evaluated in this pilot study.

METHODS

15 psoriasis patients were treated with adalimumab. At different visits before and after treatment, quantitative body surface area (qBSA) was obtained from standardized digital body images of the patients, and the psoriasis area severity index (PASI) was also monitored. SCCA were detected by using microparticle enzyme immunoassay. The serum biomarkers were also tested in healthy volunteers as normal controls. Receiver-operating characteristic (ROC) curve analysis was used to explore the optimal cutoff point of SCCA to differentiate mild and moderate-to-severe psoriasis.

RESULTS

The serum SCCA level in the psoriasis group was significantly higher (p < 0.05) than in the normal control group. After treatment, the serum SCCA levels were significantly decreased (p < 0.05). The SCCA level was well correlated with PASI and qBSA. In ROC analysis, when taking PASI = 10 or qBSA = 10% as the threshold, an optimal cutoff point of SCCA was found at 2.0 ng/mL with the highest Youden index.

CONCLUSION

Serum SCCA might be a useful quantitative biomarker for psoriasis disease severity.

Clinical Significance of Decreased Interleukin-35 Expression in Patients with Psoriasis

In psoriasis, a chronic, recurrent, inflammatory skin disease, CD4+T cells and their related cytokines play an important role in its pathogenesis. The role of interleukin (IL)-35, an immunosuppressive cytokine involved in many autoimmune diseases, is unclear in the pathogenesis of psoriasis. This study evaluated IL-35 expression and clinical significance in psoriasis. Protein and mRNA levels of specified markers were measured by enzyme-linked immunosorbent assay (ELISA) and real-time quantitative polymerase chain reaction (qRT-PCR), respectively. Results showed that plasma IL-35 concentrations were lower in patients with psoriasis than in healthy individuals (Z = -6.525, P < .0001). Ebi3 and p35 showed lower mRNA levels in peripheral blood mononuclear cells from patients with psoriasis than in healthy individuals (Z = -5.078, P < .0001, Z = -2.609, P = .009, respectively). The areas under the receiver-operating characteristic (ROC) curves of IL-35, Ebi3, and p35 for patients with psoriasis versus the control were 0.86, 0.78, and 0.64, respectively. Pearson correlation analysis showed that plasma IL-35 expression negatively correlated with interferon-gamma, tumor necrosis factor-alpha, levels of IL-23, -17, and -22, or the Psoriasis Activity and Severity Index and positively correlated with levels of transforming growth factor beta and IL-10 levels in patients with psoriasis. Summarily, IL-35 might mediate psoriasis pathogenesis by influencing the expression of Th1/Th17/Treg -related cytokines and might be a putative target in monitoring or treating psoriasis.

Dual IL-17A and IL-17F neutralisation by bimekizumab in psoriatic arthritis: evidence from preclinical experiments and a randomised placebo-controlled clinical trial that IL-17F contributes to human chronic tissue inflammation

OBJECTIVE

Interleukin (IL)-17A has emerged as pivotal in driving tissue pathology in immune-mediated inflammatory diseases. The role of IL-17F, sharing 50% sequence homology and overlapping biological function, remains less clear. We hypothesised that IL-17F, together with IL-17A, contributes to chronic tissue inflammation, and that dual neutralisation may lead to more profound suppression of inflammation than inhibition of IL-17A alone.

METHODS

Preclinical experiments assessed the role of IL-17A and IL-17F in tissue inflammation using disease-relevant human cells. A placebo-controlled proof-of-concept (PoC) clinical trial randomised patients with psoriatic arthritis (PsA) to bimekizumab (n=39) or placebo (n=14). Safety, pharmacokinetics and clinical efficacy of multiple doses (weeks 0, 3, 6 (240 mg/160 mg/160 mg; 80 mg/40 mg/40 mg; 160 mg/80 mg/80 mg and 560 mg/320 mg/320 mg)) of bimekizumab, a humanised monoclonal IgG1 antibody neutralising both IL-17A and IL-17F, were investigated.

RESULTS

IL-17F induced qualitatively similar inflammatory responses to IL-17A in skin and joint cells. Neutralisation of IL-17A and IL-17F with bimekizumab more effectively suppressed in vitro cytokine responses and neutrophil chemotaxis than inhibition of IL-17A or IL-17F alone. The PoC trial met both prespecified efficacy success criteria and showed rapid, profound responses in both joint and skin (pooled top three doses vs placebo at week 8: American College of Rheumatology 20% response criteria 80.0% vs 16.7% (posterior probability >99%); Psoriasis Area and Severity Index 100% response criteria 86.7% vs 0%), sustained to week 20, without unexpected safety signals.

CONCLUSIONS

These data support IL-17F as a key driver of human chronic tissue inflammation and the rationale for dual neutralisation of IL-17A and IL-17F in PsA and related conditions.

TRIAL REGISTRATION NUMBER

NCT02141763; Results.

Role of mesenchymal stem cells in the pathogenesis of psoriasis: current perspectives

Mesenchymal stem cells (MSCs) are multipotent nonhematopoietic stromal cells studied for their properties and importance in management of several skin diseases. This review collects and analyzes the emerging published data, which describe the function of MSCs in the pathogenesis of psoriasis.

Old and New Biological Therapies for Psoriasis

Biological therapy became available for psoriasis with the introduction of alefacept at the beginning of this century. Up to then, systemic treatment options comprised small molecule drugs, targeting the immune system in a non-specific manner. The first biologics targeted T-cell activation and migration and served as an alternative to small molecules. However, significant improvement in outcome was first accomplished with the introduction of tumor necrosis factor-α inhibitors that were already approved for other inflammatory disorders, including rheumatic diseases. Along with the progress in understanding psoriasis pathogenesis, highly targeted and effective therapies have since developed with the perspective not only to improve but to clear psoriasis. These accomplishments enable future achievement of advanced goals to individualize treatment best suited for each patient. Mechanistic studies with patients treated with the new highly targeted biologics may guide us towards these goals. This review offers an overview of biologics developed for psoriasis and illustrate a historical progress in the treatment of this common chronic inflammatory skin condition.

Obesity and inflammation: the linking mechanism and the complications

Obesity is the accumulation of abnormal or excessive fat that may interfere with the maintenance of an optimal state of health. The excess of macronutrients in the adipose tissues stimulates them to release inflammatory mediators such as tumor necrosis factor α and interleukin 6, and reduces production of adiponectin, predisposing to a pro-inflammatory state and oxidative stress. The increased level of interleukin 6 stimulates the liver to synthesize and secrete C-reactive protein. As a risk factor, inflammation is an imbedded mechanism of developed cardiovascular diseases including coagulation, atherosclerosis, metabolic syndrome, insulin resistance, and diabetes mellitus. It is also associated with development of non-cardiovascular diseases such as psoriasis, depression, cancer, and renal diseases. On the other hand, a reduced level of adiponectin, a significant predictor of cardiovascular mortality, is associated with impaired fasting glucose, leading to type-2 diabetes development, metabolic abnormalities, coronary artery calcification, and stroke. Finally, managing obesity can help reduce the risks of cardiovascular diseases and poor outcome via inhibiting inflammatory mechanisms.

Imiquimod induced ApoE-deficient mice might be a composite animal model for the study of psoriasis and dyslipideamia comorbidity

BACKGROUND

Psoriasis patients are at increased risk of developing lipid metabolism disturbances. Both psoriasis and dyslipideamia not only closely interact in disease development, but occur as mutual side effects in some medicine treatment. The interactive mechanism of the two diseases is complicated and still unclear.

OBJECTIVE

Here, we proposed applying imiquimod on the dorsal skin of ApoE^-/- mice to establish a composite animal model which formed psoriasiform skin lesions under hyperlipidemic condition.

METHOD

By comparison with corresponding wild-type(C57BL/6) mice, the composite mice model was evaluated by skin pathological features, lipid levels, immune inflammatory factors in order to clarify the diseases interplay mechanism. In addition, IL-17 mAb treatment was applied to observe the effect of IL-17 antibody on the composite animal model.

RESULTS

The results verified that imiquimod-induced ApoE^-/- mice model presented keratinocyte hyperplasia, parakeratosis, inflammatory cells infiltration and elevated serum lipid levels, and also reflected the complex interaction between inflammation and lipid metabolism. IL-17 mAb could inhibit psoriasis skin lesions with lipid accumulation via STAT3 pathway, but no influence on elevated serum cholesterol.

CONCLUSIONS

Imiquimod-induced ApoE^-/- mice model presented the pathological features of psoriasis and dyslipideamia, which could be an ideal composite animal model for the study of pathogenesis and pharmacotherapeutics of psoriasis and dyslipideamia comorbidity.

First-in-human randomized study of bimekizumab, a humanized monoclonal antibody and selective dual inhibitor of IL-17A and IL-17F, in mild psoriasis

AIMS

To assess safety, pharmacokinetics (PK) and clinical efficacy of bimekizumab (formerly UCB4940), a novel humanized monoclonal antibody and dual inhibitor of interleukin (IL)-17A and IL-17F, in subjects with mild plaque psoriasis.

METHODS

Randomized, double-blind, first-in-human study of bimekizumab in 39 subjects who received single-dose intravenous bimekizumab (8-640 mg) or placebo (NCT02529956).

RESULTS

Bimekizumab demonstrated dose-proportional linear PK and was tolerated across the dose range assessed. No subject discontinued due to treatment-emergent adverse events and no severe adverse events were reported. Bimekizumab demonstrated fast onset of clinically-meaningful effects on skin of patients with mild psoriasis as early as Week 2. Maximal improvements (100% or near 100% reductions from baseline) in all measures of disease activity were observed between Weeks 8-12 in subjects receiving 160-640 mg bimekizumab. The duration of effect at doses ≥160 mg was evident up to Weeks 12-20 after a single intravenous dose, dependent on endpoint.

CONCLUSIONS

This is the first study to demonstrate the safety, tolerability and clinical efficacy of a dual IL-17A and IL-17F inhibitor, in subjects with mild psoriasis. Bimekizumab showed fast onset of clinically-meaningful efficacy by Week 2, with a maximal or near-maximal magnitude of response that was maintained up to study Weeks 12-20. These findings support the continued clinical development of bimekizumab for diseases mediated by both IL-17A and IL-17F, including psoriasis.

The Inflammatory Response in Psoriasis: a Comprehensive Review

Psoriasis is a chronic inflammatory autoimmune disease characterized by an excessively aberrant hyperproliferation of keratinocytes. The pathogenesis of psoriasis is complex and the exact mechanism remains elusive. However, psoriasis is thought to result from a combination of genetic, epigenetic, and environmental influences. Recent studies have identified that epigenetic factors including dysregulated DNA methylation levels, abnormal histone modification and microRNAs expressions are involved in the development of psoriasis. The interplay of immune cells and cytokines is another critical factor in the pathogenesis of psoriasis. These factors or pathways include Th1/Th2 homeostasis, the Th17/Treg balance and the IL-23/Th17 axis. Th17 is believed particularly important in psoriasis due to its pro-inflammatory effects and its involvement in an integrated inflammatory loop with dendritic cells and keratinocytes, contributing to an overproduction of antimicrobial peptides, inflammatory cytokines, and chemokines that leads to amplification of the immune response. In addition, other pathways and signaling molecules have been found to be involved, including Th9, Th22, regulatory T cells, γδ T cells, CD8(+) T cells, and their related cytokines. Understanding the pathogenesis of psoriasis will allow us to develop increasingly efficient targeted treatment by blocking relevant inflammatory signaling pathways and molecules. There is no cure for psoriasis at the present time, and much of the treatment involves managing the symptoms. The biologics, while lacking the adverse effects associated with some of the traditional medications such as corticosteroids and methotrexate, have their own set of side effects, which may include reactivation of latent infections. Significant challenges remain in developing safe and efficacious novel targeted therapies that depend on a better understanding of the immunological dysfunction in psoriasis.

Increased Interleukin-17F is Associated with Elevated Autoantibody Levels and More Clinically Relevant Than Interleukin-17A in Primary Sjögren's Syndrome

Th17 related immune response is pathogenic in primary Sjögren's syndrome (pSS). However, the role of IL-17F, one potent inflammatory member of IL-17 family cytokines in pSS, has not been specifically defined. We recruited one hundred and nine pSS patients and forty-two healthy controls and their serum levels of IL-17A and IL-17F were determined by multiplex cytokine assays. White blood cell, red blood cell, neutrophil, lymphocyte, IgM, IgG, C3, C4, RF, ANA, anti-SSA antibody, and anti-SSB antibody were measured by standard laboratory techniques. EULAR Sjögren's syndrome disease activity index (ESSDAI) score was also evaluated accordingly. We found that IL-17F was significantly increased in pSS patients. Elevated levels of IL-17F were associated with increased IgG and IgM, higher titers of ANA and anti-SSA antibodies, and reduction of C3 and C4. Patients with higher disease activity also showed higher serum IL-17F levels. However, serum IL-17A was only increased in patients with longer disease duration and showed few correlation with clinical and laboratory features in pSS patients. In conclusion, IL-17F was correlated with increased autoantibody levels and disease activity in pSS and is more clinically relevant than IL-17A.

T Helper Cell Subsets in Clinical Manifestations of Psoriasis

Psoriasis is a chronic inflammatory skin disease, which is associated with systemic inflammation and comorbidities, such as psoriatic arthritis and cardiovascular diseases. The autoimmune nature of psoriasis has been established only recently, conferring a central role to epidermal CD8 T cells recognizing self-epitopes in the initial phase of the disease. Different subsets of helper cells have also been reported as key players in the psoriasis pathogenesis. Here, we reviewed the knowledge on the role of each subset in the psoriatic cascade and in the different clinical manifestations of the disease. We will discuss the role of Th1 and Th17 cells in the initiation and in the amplification phase of cutaneous inflammation. Moreover, we will discuss the recently proposed role of tissue resident Th22 cells in disease memory in sites of recurrent psoriasis and the possible involvement of Th9 cells. Finally, we will discuss the hypothesis of a link between T helper cell subsets recirculating from the skin and the systemic manifestations of psoriasis.

Elevation of serum squamous cell carcinoma antigen 2 in patients with psoriasis: associations with disease severity and response to the treatment

BACKGROUND

Squamous cell carcinoma antigen (SCCA) belongs to the ovalbumin-serpin family and is a known tumour marker. Expression of SCCA is upregulated in the serum and skin of patients with psoriasis.

OBJECTIVES

The aim of this study was to determine SCCA2 levels in association with disease severity and treatment efficacy in patients with psoriasis.

MATERIALS AND METHODS

Patients with psoriasis (n = 123) and healthy controls (n = 25) were enrolled in this prospective cross-sectional study. Enzyme-linked immunosorbent assay (ELISA) analysis was performed to determine serum SCCA2 levels. SCCA2 expression in skin was evaluated using immunohistochemical analysis. Serum SCCA2 levels were compared with Psoriasis Area Severity Index (PASI) scores. The effect of treatment on serum SCCA2 levels was assessed using serial examinations. Induction of SCCA2 by several psoriatic cytokines in human keratinocytes was evaluated.

RESULTS

The serum levels of SCCA2 were significantly higher in patients with psoriasis than healthy controls and correlated well with disease severity. Increased SCCA2 staining was observed in lesional skin but not in nonlesional skin of patients with psoriasis. In addition, SCCA2 expression levels in skin correlated with serum concentrations of SCCA2. SCCA2 significantly decreased according to improvement of PASI scores. Interleukin (IL)-17 and IL-22 synergistically increased the production of SCCA2 at both mRNA and protein levels in human keratinocytes.

CONCLUSIONS

Significant elevation of SCCA2 is associated with disease severity and reflects treatment efficacy. SCCA2 may be a useful biomarker in psoriasis, reflecting T-helper 17-type inflammation - the main determinant of the severity of psoriasis.

Dual Inhibition of Interleukin-23 and Interleukin-17 Offers Superior Efficacy in Mouse Models of Autoimmunity

Therapies targeting either interleukin (IL)-23 or IL-17 have shown promise in treating T helper 17 (Th17)-driven autoimmune diseases. Although IL-23 is a critical driver of IL-17, recognition of nonredundant and independent functions of IL-23 and IL-17 has prompted the notion that dual inhibition of both IL-23 and IL-17 could offer even greater efficacy for treating autoimmune diseases relative to targeting either cytokine alone. To test this hypothesis, we generated selective inhibitors of IL-23 and IL-17 and tested the effect of either treatment alone compared with their combination in vitro and in vivo. In vitro, using a novel culture system of murine Th17 cells and NIH/3T3 fibroblasts, we showed that inhibition of both IL-23 and IL-17 completely suppressed IL-23-dependent IL-22 production from Th17 cells and cooperatively blocked IL-17-dependent IL-6 secretion from the NIH/3T3 cells to levels below either inhibitor alone. In vivo, in the imiquimod induced skin inflammation model, and in the myelin oligodendrocyte glycoprotein peptide-induced experimental autoimmune encephalomyelitis model, we demonstrated that dual inhibition of IL-17 and IL-23 was more efficacious in reducing disease than targeting either cytokine alone. Together, these data support the hypothesis that neutralization of both IL-23 and IL-17 may provide enhanced benefit against Th17 mediated autoimmunity and provide a basis for a therapeutic strategy aimed at dual targeting IL-23 and IL-17.

Dual Inhibition of TNFR1 and IFNAR1 in Imiquimod-Induced Psoriasiform Skin Inflammation in Mice

Psoriasis is a chronic inflammatory skin disease affecting 2-3% of the world population and is mainly characterized by epidermal hyperplasia, scaling, and erythema. A prominent role for TNF in the pathogenesis of psoriasis has been shown, and consequently various types of TNF antagonists such as etanercept and infliximab have been used successfully. Recently, increasing amounts of data suggest that type I IFNs are also crucial mediators of psoriasis. To investigate whether blocking their respective receptors would be useful, TNFR1- and IFNAR1-deficient mice were challenged with Aldara, which contains imiquimod, and is used as an experimental model to induce psoriasis-like skin lesions in mice. Both transgenic mice showed partial protection toward Aldara-induced inflammation compared with control groups. Additionally, TNFR1 knockout mice showed sustained type I IFN production in response to Aldara. Double knockout mice lacking both receptors showed superior protection to Aldara in comparison with the single knockout mice and displayed reduced levels of IL-12p40, IL-17F, and S100A8, indicating that the TNF and type I IFN pathways contribute significantly to inflammation upon treatment with Aldara. Our findings reveal that dual inhibition of TNFR1 and IFNAR1 may represent a potential novel strategic treatment of psoriasis.