Type I interferon-associated cytotoxic inflammation in cutaneous lupus erythematosus

Chemokines and chemokine receptors: Potential therapeutic targets in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease that affects connective tissue and can lead to multisystem organ damage. Chemokines are a class of small proteins that interact with receptors and participate in a variety of physiological functions, including cell growth, differentiation, apoptosis and distribution. They also play important roles in pathological processes, such as the inflammatory response, wound repair, tumor formation and metastasis. Previous studies have shown that the levels of chemokines and their receptors are elevated in the blood and inflamed tissues of SLE patients. In addition, chemokine ligand-receptor interactions control the recruitment of leukocytes into tissues, suggesting that chemokines and their receptors may be biomarkers and therapeutic targets for SLE. This review summarizes the causative role of chemokines and their receptors in SLE, as well as their clinical values and challenges as potential biomarkers and therapeutic targets.

Implications of Inflammatory Processes on a Developing Central Nervous System in Childhood-Onset Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease that is increasingly affecting pediatric and adult populations. Neuropsychiatric manifestations (ie, cognitive dysfunction and mood disorders) appear to occur with greater severity and poorer prognosis in childhood-onset SLE (cSLE) versus adult-onset SLE, negatively impacting school function, self-management, and psychosocial health, as well as lifelong health-related quality of life. In this review, we describe pathogenic mechanisms active in cSLE, such as maladaptive inflammatory processes and ischemia, which are hypothesized to underpin central phenotypes in patients with cSLE, and the role of alterations in protective central nervous system (CNS) barriers (ie, the blood-brain barrier) are also discussed. Recent findings derived from novel neuroimaging approaches are highlighted because the methods employed in these studies hold potential for identifying CNS abnormalities that would otherwise remain undetected with conventional multiple resonance imaging studies (eg, T2-weighted or fluid-attenuated inversion recovery sequences). Furthermore, we propose that a more robust presentation of neuropsychiatric symptoms in cSLE is in part due to the harmful impact of a chronic inflammatory insult on a developing CNS. Although the immature status of the CNS may leave patients with cSLE more vulnerable to harboring neuropsychiatric manifestations, the same property may represent a greater urgency to reverse the maladaptive effects associated with a proneuroinflammatory state, provided that effective diagnostic tools and treatment strategies are available. Finally, considering the crosstalk among the CNS and other organ systems affected in cSLE, we postulate that a finer understanding of this interconnectivity and its role in the clinical presentation in cSLE is warranted.

Impaired activation of plasmacytoid dendritic cells via toll-like receptor 7/9 and STING is mediated by melanoma-derived immunosuppressive cytokines and metabolic drift

Introduction

Plasmacytoid dendritic cells (pDCs) infiltrate a large set of human cancers. Interferon alpha (IFN-α) produced by pDCs induces growth arrest and apoptosis in tumor cells and modulates innate and adaptive immune cells involved in anti-cancer immunity. Moreover, effector molecules exert tumor cell killing. However, the activation state and clinical relevance of pDCs infiltration in cancer is still largely controversial. In Primary Cutaneous Melanoma (PCM), pDCs density decreases over disease progression and collapses in metastatic melanoma (MM). Moreover, the residual circulating pDC compartment is defective in IFN-α production.

Methods

The activation of tumor-associated pDCs was evaluated by in silico and microscopic analysis. The expression of human myxovirus resistant protein 1 (MxA), as surrogate of IFN-α production, and proximity ligation assay (PLA) to test dsDNA-cGAS activation were performed on human melanoma biopsies. Moreover, IFN-α and CXCL10 production by in vitro stimulated (i.e. with R848, CpG-A, ADU-S100) pDCs exposed to melanoma cell lines supernatants (SN-mel) was tested by intracellular flow cytometry and ELISA. We also performed a bulk RNA-sequencing on SN-mel-exposed pDCs, resting or stimulated with R848. Glycolytic rate assay was performed on SN-mel-exposed pDCs using the Seahorse XFe24 Extracellular Flux Analyzer.

Results

Based on a set of microscopic, functional and in silico analyses, we demonstrated that the melanoma milieu directly impairs IFN-α and CXCL10 production by pDCs via TLR-7/9 and cGAS-STING signaling pathways. Melanoma-derived immunosuppressive cytokines and a metabolic drift represent relevant mechanisms enforcing pDC-mediated melanoma escape.

Discussion

These findings propose a new window of intervention for novel immunotherapy approaches to amplify the antitumor innate immune response in cutaneous melanoma (CM).

IL-1β and IL-17 in cutaneous lupus erythematous skin biopsies: could immunohistochemicals indicate a tendency towards systemic involvement?

BACKGROUND

Only a fraction of patients with cutaneous lupus erythematosus (CLE) will eventually progress toward systemic disease (SLE).

OBJECTIVE

To find inflammatory biomarkers which could predict the progression of cutaneous lupus erythematosus (CLE) into systemic lupus erythematosus (SLE) using immunohistochemical (IHC) assays.

METHODS

Immunohistochemical markers for cytotoxic, inflammatory, and anti-inflammatory responses and morphometric methods were applied to routine paraffin sections of skin biopsies, taken from lesions of 59 patients with discoid lupus, subacute lupus, and lupus tumidus. For the diagnosis of SLE, patients were classified by both the American College of Rheumatology (ACR-82) and the Systemic Lupus International Collaborating Clinics (SLICC-12) systems.

RESULTS

Skin samples from CLE/SLE+patients presented higher expression of IL-1β (ARC-82: p=0.024; SLICC-12: p=0.0143) and a significantly higher number of cells marked with granzyme B and perforin (ARC: p=0.0097; SLICC-12: p=0.0148). Biopsies from CLE/SLE- individuals had higher expression of IL-17 (ARC-82: p=0.0003; SLICC-12: p=0.0351) and presented a positive correlation between the density of granzyme A+and FoxP3+ cells (ARC-82: p=0.0257; SLICC-12: p=0.0285) and CD8+ cells (ARC-82: p=0.0075; SLICC-12: p=0.0102), as well as between granulysin-positive and CD8+ cells (ARC-82: p=0.0024; SLICC-12: p=0.0116).

STUDY LIMITATIONS

Patients were evaluated at a specific point in their evolution and according to the presence or not of systemic disease. The authors cannot predict how many more, from each group, would have evolved towards SLE in the following years.

CONCLUSIONS

In this cohort, immunohistochemical findings suggested that patients with a tendency to systemic disease will show strong reactivity for IL-1β, while those with purely cutaneous involvement will tend to express IL-17 more intensely.

Bioinformatics analyses of gene expression profile to identify pathogenic mechanisms for COVID-19 infection and cutaneous lupus erythematosus

Objective

The global mortality rates have surged due to the ongoing coronavirus disease 2019 (COVID-19), leading to a worldwide catastrophe. Increasing incidents of patients suffering from cutaneous lupus erythematosus (CLE) exacerbations after either contracting COVID-19 or getting immunized against it, have been observed in recent research. However, the precise intricacies that prompt this unexpected complication are yet to be fully elucidated. This investigation seeks to probe into the molecular events inciting this adverse outcome.

Method

Gene expression patterns from the Gene Expression Omnibus (GEO) database, specifically GSE171110 and GSE109248, were extracted. We then discovered common differentially expressed genes (DEGs) in both COVID-19 and CLE. This led to the creation of functional annotations, formation of a protein-protein interaction (PPI) network, and identification of key genes. Furthermore, regulatory networks relating to these shared DEGs and significant genes were constructed.

Result

We identified 214 overlapping DEGs in both COVID-19 and CLE datasets. The following functional enrichment analysis of these DEGs highlighted a significant enrichment in pathways related to virus response and infectious disease in both conditions. Next, a PPI network was constructed using bioinformatics tools, resulting in the identification of 5 hub genes. Finally, essential regulatory networks including transcription factor-gene and miRNA-gene interactions were determined.

Conclusion

Our findings demonstrate shared pathogenesis between COVID-19 and CLE, offering potential insights for future mechanistic investigations. And the identification of common pathways and key genes in these conditions may provide novel avenues for research.

Aberrant inflammasome activation as a driving force of human autoimmune skin disease

Autoimmune skin diseases are understood as conditions in which the adaptive immune system with autoantigen-specific T cells and autoantibody-producing B cells reacting against self-tissues plays a crucial pathogenic role. However, there is increasing evidence that inflammasomes, which are large multiprotein complexes that were first described 20 years ago, contribute to autoimmune disease progression. The inflammasome and its contribution to the bioactivation of interleukins IL-1β and IL-18 play an essential role in combating foreign pathogens or tissue damage, but may also act as a pathogenic driver of myriad chronic inflammatory diseases when dysfunctionally regulated. Inflammasomes containing the NOD-like receptor family members NLRP1 and NLRP3 as well as the AIM2-like receptor family member AIM2 have been increasingly investigated in inflammatory skin conditions. In addition to autoinflammatory diseases, which are often associated with skin involvement, the aberrant activation of the inflammasome has also been implied in autoimmune diseases that can either affect the skin besides other organs such as systemic lupus erythematosus and systemic sclerosis or are isolated to the skin in humans. The latter include, among others, the T-cell mediated disorders vitiligo, alopecia areata, lichen planus and cutaneous lupus erythematosus as well as the autoantibody-driven blistering skin disease bullous pemphigoid. Some diseases are characterized by both autoinflammatory and autoimmune responses such as the chronic inflammatory skin disease psoriasis. Further insights into inflammasome dysregulation and associated pathways as well as their role in forming adaptive immune responses in human autoimmune skin pathology could potentially offer a new field of therapeutic options in the future.

Characterization of B cells in lupus erythematosus skin biopsies in the context of different immune cell infiltration patterns

Cutaneous lesions in lupus erythematosus (LE) subtypes are heterogenous. In line with the heterogeneity of the clinical presentation, the underlying lesional inflammation in LE skin samples is defined by different immune cell infiltrates. Pathophysiologically, lesional inflammation is driven by autoreactive cytotoxic T cells, targeting keratinocytes; plasmacytoid dendritic cells (pDCs), producing large amounts of interferon (IFN); and B cells, whose function in cutaneous LE is still unclear. This study aims to (a) classify inflammatory patterns with regard to the dominating cell type or cytokine expression and (b) investigating the specific role of B cells in LE skin lesions. Therefore, the immunohistological expression of inflammatory surrogates (CD20, CD123, MXA) in skin samples of n = 119 LE (subtypes: subacute cutaneous LE, chronic discoid LE, chilblain LE, LE tumidus, other LE) and n = 17 patients with inflammatory skin diseases (atopic dermatitis, psoriasis) were assessed. Samples were classified with regard to inflammatory groups. In addition multiplex-immunohistochemical analyses of n = 17 LE skin samples focusing on lesional B cells were conducted. In this study, we show that cutaneous lesions present with eight different inflammatory groups dominated by B cells, pDCs, a strong IFN expression, or overlapping patterns. Altogether, LE subtypes show heterogenous infiltration regardless of LE subtype, certain subtypes display a preference for infiltration groups. Furthermore, lesional B cells either form diffuse infiltrates or pseudofollicular structures, wherein they show antigen-presenting and T cell-activating properties. Altogether, in the light of emerging targeted therapeutic options, we suggest histological assessment in regard to B-cell or pDC preponderance to allow tailored treatment decisions.

Current Concepts on Pathogenic Mechanisms and Histopathology in Cutaneous Lupus Erythematosus

Cutaneous lupus erythematosus (CLE) is an interferon (IFN)-driven autoimmune disease that may be limited to the skin or can be associated with systemic lupus erythematosus (SLE). CLE occurs in several morphologic subtypes ranging from isolated, disc-shaped plaques to disseminated skin lesions. The typical histopathologic pattern of skin lesions is named interface dermatitis and characterized by a lymphocytic infiltrate and necroptotic keratinocytes at the dermo-epidermal junction. Other histopathologic patterns primarily involve the dermis or subcutis, depending on the subtype. One critical mechanism in CLE is the chronic reactivation of innate and adaptive immune pathways. An important step in this process is the recognition of endogenous nucleic acids released from dying cells by various pattern recognition receptors (PRRs), including Toll-like receptors (TLRs) and other cytosolic receptors. Crucial cells in CLE pathogenesis comprise plasmacytoid dendritic cells (pDCs) as major producers of type I IFN, T cells exerting cytotoxic effects, and B cells, previously believed to contribute via secretion of autoantibodies. However, B cells are increasingly considered to have additional functions, supported by studies finding them to occur in highest numbers in chronic discoid lupus erythematosus (CDLE), a subtype in which autoantibodies are often absent. More precise knowledge of how CLE subtypes differ pathophysiologically may allow a tailored pharmacotherapy in the future, taking into account the specific molecular signature in relation to the morphologic subtype.

Activation of NLRP3 Inflammasome in the Skin of Patients with Systemic and Cutaneous Lupus Erythematosus

NLRP3 inflammasome is suggested to contribute to the complex pathogenesis of systemic lupus erythematosus, but its role in cutaneous lupus erythematosus has not been addressed. This study investigated the expression of NLRP3 inflammasome components and levels of type I interferons in the skin of 20 patients with cutaneous lupus erythematosus. Expression of NLRP1/3, adaptor protein ASC (apoptosis-associated speck-like protein), caspase-1, interferon-α (IFN-α), myxovirus resistance protein (MxA), and interferon-induced proteins 1 and 2 (IFIT 1/2) in the skin was assessed using reverse transcription quantitative real-time PCR (RT-qPCR), western blotting and immunohistochemistry. Serum interferon-α protein levels from 12 patients were measured using digital enzyme-linked immunoassay (ELISA). Interleukin-1β expression was significantly upregulated in the lesional skin of patients with cutaneous lupus erythematosus compared with their uninvolved skin. However, NLRP1/3, ASC and caspase-1 were not significantly upregulated compared with the skin of control persons. IFN-α and IFN-induced proteins MxA and IFIT1/2 were strongly expressed in cutaneous lupus erythematosus skin. Variability in the expression of NLRP3 inflammasome components among patients suggests heterogeneity of pathological pathways in cutaneous lupus erythematosus.

Using Gene Expression Analysis to Understand Complex Autoimmune Skin Disease Patients: A Series of Four Canine Cutaneous Lupus Erythematosus Cases

Cutaneous Lupus Erythematosus (CLE) is an autoimmune skin disease that occurs in almost two-thirds of people with Systemic Lupus Erythematosus (SLE) and can exist as its own entity. Despite its negative impact on the quality of life of patients, lupus pathogenesis is not fully understood. In recent years, the role of gene expression analysis has become important in understanding cellular functions and disease causation within and across species. Interestingly, dogs also develop CLE, providing a spontaneous animal model of disease. Here, we present a targeted transcriptomic analysis of skin biopsies from a case series of four dogs with complex autoimmunity with suspected CLE. We identified 92 differentially expressed genes (DEGs), including type 1 interferon, B cell, and T cell-related genes, in the four cases compared to healthy skin margin controls. Additionally, we compared our results with existing CLE datasets from humans and mice and found that humans and canines share 49 DEGs, whereas humans and mice shared only 25 DEGs in our gene set. Immunohistochemistry of IFNG and CXCL10, two of the most highly upregulated inflammatory mediators, confirmed protein-level expression and revealed immune cells as the primary source of CXCL10 in dogs with SLE, whereas keratinocytes stained strongly for CXCL10 in dogs without SLE. We propose that gene expression analysis may aid the diagnosis of complex autoimmune skin diseases and that dogs may provide important insights into CLE and SLE pathogeneses, or more broadly, skin manifestations during systemic autoimmunity.

Dermatomyositis With Anti-MDA5 Antibodies: Bioclinical Features, Pathogenesis and Emerging Therapies

Anti-MDA5 dermatomyositis is a rare systemic autoimmune disease, historically described in Japanese patients with clinically amyopathic dermatomyositis and life-threatening rapidly progressive interstitial lung disease. Subsequently, the complete clinical spectrum of the disease was enriched by skin, articular and vascular manifestations. Depending on the predominance of these symptoms, three distinct clinical phenotypes with different prognosis are now defined. To date, the only known molecular component shared by the three entities are specific antibodies targeting MDA5, a cytosolic protein essential for antiviral host immune responses. Several biological tools have emerged to detect these antibodies, with drawbacks and limitations for each of them. However, the identification of this highly specific serological marker of the disease raises the question of its role in the pathogenesis. Although current knowledge on the pathogenic mechanisms that take place in the disease are still in their enfancy, several lines of evidence support a central role of interferon-mediated vasculopathy in the development of skin and lung lesions, as well as a possible pathogenic involvement of anti-MDA5 antibodies. Here, we review the clinical and biological evidences in favor of these hypothesis, and we discuss the contribution of emerging therapies that shed some light on the pathogenesis of the disease.

Resident Memory T Cells in Autoimmune Skin Diseases

Tissue resident memory T cells (TRM) are a critical component of the immune system, providing the body with an immediate and highly specific response against pathogens re-infecting peripheral tissues. More recently, however, it has been demonstrated that TRM cells also form during autoimmunity. TRM mediated autoimmune diseases are particularly destructive, because unlike foreign antigens, the self-antigens are never cleared, continuously activating self-reactive TRM T cells. In this article, we will focus on how TRMs mediate disease in autoimmune skin conditions, specifically vitiligo, psoriasis, cutaneous lupus erythematosus, alopecia areata and frontal fibrosing alopecia.

Cutaneous lupus erythematosus: The impact of self-amplifying innate and adaptive immune responses and future prospects of targeted therapies

Cutaneous lupus erythematosus (CLE) is a heterogeneous autoimmune disease encompassing a broad spectrum of skin conditions including localized plaques or widespread lesions, which may be accompanied by systemic involvement (systemic lupus erythematosus (SLE)). The disease is characterized by necroptotic keratinocytes and a cytotoxic immune cell infiltrate at the dermo-epidermal junction (DEJ), orchestrated by interferon (IFN)-regulated proinflammatory cytokines. Molecular analyses revealed a strong upregulation of innate and adaptive immune pathways in lesional skin including DNA-recognition pathways, chemokine signalling, antigen presentation and B- and T-cell activation, which are believed to interact in a complex self-amplifying network. Concerning adaptive immune signalling, particularly B cells are currently being studied as there is growing evidence for additional abilities besides autoantibody expression in skin autoimmunity. These detailed insights have paved the way for the development of drugs targeting crucial molecules of pathogenic immune cells and pathways. Moreover, they forwarded the understanding of distinct molecular mechanisms within CLE subtypes, which might enable a more mechanism-directed, stratified pharmacotherapy of LE skin lesions in the future.

Current Insights in Cutaneous Lupus Erythematosus Immunopathogenesis

Cutaneous Lupus Erythematosus (CLE) is a clinically diverse group of autoimmune skin diseases with shared histological features of interface dermatitis and autoantibodies deposited at the dermal-epidermal junction. Various genetic and environmental triggers of CLE promote infiltration of T cells, B cells, neutrophils, antigen presenting cells, and NK cells into lesional skin. In this mini-review, we will discuss the clinical features of CLE, insights into CLE immunopathogenesis, and novel treatment approaches.

Cutaneous lupus erythematosus: new insights into pathogenesis and therapeutic strategies

Cutaneous lupus erythematosus (CLE) is an autoimmune disease that can present as an isolated skin disease or as a manifestation within the spectrum of systemic lupus erythematosus. The clinical spectrum of CLE is broad, ranging from isolated discoid plaques to widespread skin lesions. Histologically, skin lesions present as interface dermatitis (inflammation of the skin mediated by anti-epidermal responses), which is orchestrated by type I and type III interferon-regulated cytokines and chemokines. Both innate and adaptive immune pathways are strongly activated in the formation of skin lesions owing to continuous re-activation of innate pathways via pattern recognition receptors (PRRs). These insights into the molecular pathogenesis of skin lesions in CLE have improved our understanding of the mechanisms underlying established therapies and have triggered the development of targeted treatment strategies that focus on immune cells (for example, B cells, T cells or plasmacytoid dendritic cells), as well as immune response pathways (for example, PRR signalling, Janus kinase (JAK)-signal transducer and activator of transcription (STAT) signalling and nuclear factor-κB signalling) and their cytokines and chemokines (for example, type I interferons, CXC-chemokine ligand 10 (CXCL10), IL-6 and IL-12).

Spleen tyrosine kinase (SYK) is a potential target for the treatment of cutaneous lupus erythematosus patients

Spleen tyrosine kinase (SYK) is a protein kinase involved in cell proliferation and the regulation of inflammatory pathways. Due to the increasing evidence that kinase inhibitors have potential as specific anti-inflammatory drugs, we have investigated the potential for SYK inhibition as a therapeutic target in autoimmune diseases, particularly cutaneous lupus erythematosus (CLE). Skin samples of patients with different CLE subtypes and appropriate controls were analysed for the expression of SYK and SYK-associated pro-inflammatory mediators via gene expression analysis and immunohistochemistry. The functional role of SYK in keratinocytes was investigated in vitro, using LE-typical pro-inflammatory stimuli and a selective inhibitor of SYK. SYK-associated genes are strongly upregulated in CLE skin lesions. Importantly, phosphorylated SYK (pSYK) is strongly expressed by several immune cell types and also keratinocytes in CLE skin. In vitro, immunostimulatory nucleic acids are capable of inducing SYK phosphorylation in keratinocytes leading to the induction of pro-inflammatory cytokines, while small-molecule SYK inhibition decreases the expression of these proteins. The results demonstrate that pSYK is expressed by immune cells and keratinocytes in skin lesions of CLE patients. LE-typical stimuli induce the expression of pSYK in vitro. Small-molecule SYK inhibition leads to a reduction of pSYK expression and downregulation of pro-inflammatory cytokines in keratinocytes. We therefore believe that pSYK provides a potential future drug target for the treatment of patients who suffer from CLE and related skin disorders. Specifically, our study reveals evidence supporting the use of topical SYK inhibitors in treating lupus.

Advances in the treatment of cutaneous lupus erythematosus

Lupus erythematosus (LE) is a multifactorial autoimmune disease with clinical manifestations of differing severity which may present with skin manifestations as primary sign of the disease (cutaneous lupus erythematosus, CLE) or as part of a disease spectrum (systemic lupus erythematosus, SLE). To date, no drugs are approved specifically for the treatment of CLE and only single agents have been applied in randomized controlled trials. Therefore, topical and systemic agents are used "off-label", primarily based on open-label studies, case series, retrospective analyses, and expert opinions. In contrast, several agents, such as hydroxychloroquine, chloroquine, cyclophosphamide, azathioprine, and belimumab, are approved for the treatment of SLE. Recent approaches in the understanding of the molecular pathogenesis of LE enabled the development of further new agents, which target molecules such as interleukin 6 (IL-6) and interferon (IFN). Only single trials, however, applied these new agents in patients with cutaneous involvement of the disease and/or included endpoints which evaluated the efficacy of these agents on skin manifestations. This article provides an updated review on new and recent approaches in the treatment of CLE.

Microarray study reveals a transforming growth factor-β-dependent mechanism of fibrosis in discoid lupus erythematosus

BACKGROUND

Discoid lupus erythematosus (DLE) is characterized by scarring lesions that develop and perpetuate fibrotic lesions. These are not observed in subacute cutaneous lupus erythematosus (SCLE). The pathophysiological basis of this is currently unknown.

OBJECTIVES

To identify contradistinctive signalling pathways and cellular signatures between the two type of lupus, with a focus on the molecular mechanisms leading to fibrosis.

METHODS

We conducted a gene expression microarray analysis in lesional and nonlesional skin biopsy specimens of patients with DLE (n = 10) and SCLE (n = 10). Confirmatory reverse-transcriptase quantitative polymerase chain reaction (RT-qPCR) and immunohistochemistry were performed on selected transcripts in a new cohort of paraffin-embedded skin biopsies (n = 20). Changes over time of a group of selected inflammatory and fibrotic genes were also evaluated in a second biopsy taken 12 weeks later. In vitro functional studies were performed in primary isolated fibroblasts.

RESULTS

Compared with nonlesional skin, DLE samples expressed a distinctive T-cell gene signature. DLE samples displayed a significant CD4 T-cell enrichment with an imbalance towards T helper 1 cytokine predominance and a relative increased forkhead box (FOX)P3 response. RT-qPCR and immunochemical analysis over time showed a progressive increment of fibrotic markers and persistent FOXP3 recruitment. Ex vivo upregulation of SERPINE1, MMP9, TGFBR1, phosphorylated SMAD3 and TGFB1 suggested a transforming growth factor (TGF)-β-dependent mechanism of fibrosis in DLE, also confirmed by the results observed following in vitro stimulation with TGF-β.

CONCLUSIONS

These results highlight major pathogenic pathways in DLE and provide novel molecular targets for the development of new therapies. The data suggest the existence of a TGF-β-dependent pathway inducing fibrosis in DLE.

Cicatricial alopecia: What’s new in etiology?

Cicatricial alopecia is a rare, clinically diversified set of disorders causing permanent and irreversible hair loss, which often results in serious discomfort and patient’s mental problems.

Clinically, this form of irreversible hair loss is characterized by visible loss of hair follicle openings in the bald spots. Histologically, it consists in destroying a hair follicle and replacing it with fibrocartilage. Such disorders are perceived as primary if a hair follicle itself is the target of the disease process and secondary if hair follicles are damaged incidentally in the context of more general tissue damage (e.g. deep skin infections, thermal burns, trauma or ionizing radiation).

In this article we tried to summarize the knowledge on possible pathogenic mechanisms of cicatricial alopecia. The presented factors usually overlap and affect prognosis of particular patients. Their profound understanding may enable further research on the treatment methods of this challenging disease unit.

Cutaneous lupus erythematosus: pathogenesis, clinical pattern, diagnostics, therapy

This article contains the latest information about the mechanisms of development of lupus erythematosus based on the literature review. The modern classification of specific and non-specific skin lesions in lupus erythematosus is shown.The authors described the clinical pattern of cutaneous forms of lupus erythematosus very detailed. the data about pathological and immunological criteria for the disease diagnostics, modern methods of pharmacotherapy lupus erythematosus was classified.

Association of CXCL10 and CXCL13 levels with disease activity and cutaneous manifestation in active adult-onset Still's disease

INTRODUCTION

C-X-C motif chemokine 10 (CXCL10) is produced in response to interferon-γ, and tumor necrosis factor-α (TNF-α) triggers the accumulation of activated lymphocytes. CXCL13 is constitutively expressed in secondary lymphoid tissues, and the expression is upregulated by TNF-α, via T cell stimulation. It appears that CXCL10 and CXCL13 could play a potential role in the pathogenesis of adult-onset Still's disease (AOSD), therefore, we investigated the associations between CXCL10 and CXCL13 levels and clinical manifestations in patients with active AOSD.

METHODS

Blood samples were collected from 39 active AOSD patients, 32 rheumatoid arthritis (RA) patients and 40 healthy controls (HC). Of the AOSD patients, follow-up samples were collected from 15 9.6 ± 9.2 months later. Serum levels of CXCL10 and CXCL13 were determined using enzyme-linked immunosorbent assay. CXCL10, CXCL13, and C-X-C chemokine receptor type 3 (CXCR3) expression levels in biopsy specimens obtained from 26 AOSD patients with skin rashes were investigated via immunohistochemistry.

RESULTS

The CXCL10 levels in AOSD patients (1,031.3 ± 2,019.6 pg/mL) were higher than in RA (146.3 ± 91.4 pg/mL, p = 0.008) and HC (104.4 ± 47.9 pg/mL, p = 0.006). Also, the CXCL13 levels of AOSD patients (158.8 ± 151.2 pg/mL) were higher than those of RA (54.4 ± 61.1 pg/mL, p < 0.001) and HC (23.5 ± 18.1 pg/mL, p < 0.001). Serum CXCL10 levels correlated with ferritin and systemic scores. Serum CXCL13 levels correlated with those of hemoglobin, C-reactive protein, ferritin, and albumin, and systemic scores. In follow-up AOSD patients, the levels of CXCL10 and CXCL13 fell significantly (153.7 ± 130.1 pg/mL, p = 0.002, and 89.1 ± 117.4 pg/mL, p = 0.001, respectively). On immunohistochemistry, the percentages of inflammatory cells expressing CXCL10 ranged from 1 to 85%, CXCL13 from 1 to 72%, and CXCR3 from 2 to 65%. The percentage of CXCL10-positive inflammatory cells was higher in skin biopsy samples exhibiting mucin deposition than in those that did not (p = 0.01). CXCL13 levels were correlated with those of CD4 and CD68.

CONCLUSIONS

Serum CXCL10 and CXCL13 levels may serve as clinical markers for assessment of disease activity in AOSD. CXCL10/CXCR3 and CXCL13 may contribute to the inflammatory response, especially skin manifestations thereof, in AOSD.

Genome-wide transcriptional profiling of chronic cutaneous lupus erythematosus (CCLE) peripheral blood identifies systemic alterations relevant to the skin manifestation

Major gaps remain regarding pathogenetic mechanisms underlying clinical heterogeneity in lupus erythematosus (LE). As systemic changes are likely to underlie skin specific manifestation, we analyzed global gene expression in peripheral blood of a small cohort of chronic cutaneous LE (CCLE) patients and healthy individuals. Unbiased hierarchical clustering distinguished patients from controls revealing a "disease" based signature. Functional annotation of the differentially expressed genes (DEGs) highlight enrichment of interferon related immune response and apoptosis signatures, along with other key pathways. There is a 26% overlap of the blood and lesional skin transcriptional profile from a previous analysis by our group. We identified four transcriptional "hot spots" at chromosomal regions harboring statistically increased numbers of DEGs which offer prioritized potential loci for downstream fine mapping studies in the search for CCLE specific susceptibility loci. Additionally, we uncover evidence to support both shared and distinct mechanisms for cutaneous and systemic manifestations of lupus.

Lichen planopilaris is characterized by immune privilege collapse of the hair follicle's epithelial stem cell niche

Lichen planopilaris (LPP) is a chronic inflammatory disease of unknown pathogenesis that leads to permanent hair loss. Whilst destruction of epithelial hair follicle stem cells (eHFSCs) that reside in an immunologically protected niche of the HF epithelium, the bulge, is a likely key event in LPP pathogenesis, this remains to be demonstrated. We have tested the hypotheses that bulge immune privilege (IP) collapse and inflammation-induced eHFSC death are key components in the pathogenesis of LPP. Biopsies of lesional and non-lesional scalp skin from adult LPP patients (n = 42) were analysed by quantitative (immuno)histomorphometry, real-time quantitative polymerase chain reaction (qRT-PCR), laser capture microdissection and microarray analysis, or skin organ culture. At both the protein and transcriptional level, lesional LPP HFs showed evidence for bulge IP collapse (ie increased expression of MHC class I and II, β2microglobulin; reduced TGFβ2 and CD200 expression). This was accompanied by a Th1-biased cytotoxic T cell response (ie increased CD8(+) GranzymeB(+) T cells and CD123(+) plasmacytoid dendritic cells, with increased CXCR3 expression) and increased expression of interferon-inducible chemokines (CXCL9/10/11). Interestingly, lesional LPP eHFSCs showed both increased proliferation and apoptosis in situ. Microarray analysis revealed a loss of eHFSC signatures and increased expression of T cell activation/binding markers in active LPP, while bulge PPARγ transcription was unaltered compared to non-lesional LPP HFs. In organ culture of non-lesional LPP skin, interferon-γ (IFNγ) induced bulge IP collapse. LPP is an excellent model disease for studying and preventing immune destruction of human epithelial stem cells in situ. These novel findings raise the possibility that LPP represents an autoimmune disease in whose pathogenesis IFNγ-induced bulge IP collapse plays an important role. Therapeutically, bulge IP protection/restoration may help to better manage this highly treatment-resistant cicatricial alopecia.

Dominant Th1 and minimal Th17 skewing in discoid lupus revealed by transcriptomic comparison with psoriasis

Discoid lupus erythematosus (DLE) is the most common skin manifestation of lupus. Despite its high frequency in systemic lupus in addition to cases without extracutaneous manifestations, targeted treatments for DLE are lacking, likely because of a dearth of knowledge of the molecular landscape of DLE skin. Here, we profiled the transcriptome of DLE skin in order to identify signaling pathways and cellular signatures that may be targeted for treatment purposes. Further comparison of the DLE transcriptome with that of psoriasis, a useful reference given our extensive knowledge of molecular pathways in this disease, provided a framework to identify potential therapeutic targets. Although a growing body of data support a role for IL-17 and T helper type 17 (Th17) cells in systemic lupus, we show a relative enrichment of IFN-γ-associated genes without that for IL-17-associated genes in DLE. Extraction of T cells from the skin of DLE patients identified a predominance of IFN-γ-producing Th1 cells and an absence of IL-17-producing Th17 cells, complementing the results from whole-skin transcriptomic analyses. These data therefore support investigations into treatments for DLE that target Th1 cells or the IFN-γ signaling pathway.

Treatment options for alopecia: an update, looking to the future

INTRODUCTION

Hair loss is a very common complaint. The diagnosis is based on clinical, dermoscopic and pathological examination. The treatment is usually continuous and requires strong compliance.

AREAS COVERED

This article aims to i) summarize current treatment options for the most common forms of hair loss; ii) update the literature on treatment options to emerge over the 3 years since the release of the first edition of this article in 2009; and iii) outline future strategies for treating alopecia.

EXPERT OPINION

There is good evidence-based information for the treatment of androgenetic alopecia. There are very few good-quality randomized studies, and no information about long-term results for most of the available treatments for alopecia areata and cicatricial alopecias. Significant research success has been achieved over the past few years through i) discovering the genetic profile of alopecia areata; ii) working on follicular neogenesis in androgenetic alopecia; and iii) discovering the PPAR-γ pathway in scarring alopecia.

Roles of pro- and anti-inflammatory cytokines in the pathogenesis of SLE

SLE is an autoimmune inflammatory disease in which various pro- and anti-inflammatory cytokines, including TGF-β, IL-10, BAFF, IL-6, IFN-α, IFN-γ, IL-17, and IL-23, play crucial pathogenic roles. Virtually, all these cytokines can be generated by both innate and adaptive immune cells and exert different effects depending on specific local microenvironment. They can also interact with each other, forming a complex network to maintain delicate immune homeostasis. In this paper, we elaborate on the abnormal secretion and functions of these cytokines in SLE, analyze their potential pathogenic roles, and probe into the possibility of them being utilized as targets for therapy.

Activation of type I interferon pathway in systemic lupus erythematosus: association with distinct clinical phenotypes

Growing evidence over the last few years suggests a central role of type I IFN pathway in the pathogenesis of systemic autoimmune disorders. Data from clinical and genetic studies in patients with systemic lupus erythematosus (SLE) and lupus-prone mouse models, indicates that the type I interferon system may play a pivotal role in the pathogenesis of several lupus and associated clinical features, such as nephritis, neuropsychiatric and cutaneous lupus, premature atherosclerosis as well as lupus-specific autoantibodies particularly against ribonucleoproteins. In the current paper, our aim is to summarize the latest findings supporting the association of type I IFN pathway with specific clinical manifestations in the setting of SLE providing insights on the potential use of type I IFN as a therapeutic target.

Recent advances in cytokines in cutaneous and systemic lupus erythematosus

Lupus erythematosus (LE) includes a broad spectrum of diseases from a cutaneous-limited type to a systemic type. Systemic lupus erythematosus (SLE) is a systemic autoimmune disease which affects multiple organs. Cutaneous lupus erythematosus (CLE) includes skin symptoms seen in SLE and cutaneous-limited LE. Although immune abnormalities, as well as heritable, hormonal and environmental factors, are involved in the pathology of LE, the actual pathogenesis is still unclear. Recently, the involvement of various cytokines has been shown in the pathogenesis of LE. Moreover, some trials with biological agents targeted specific cytokines are also ongoing for SLE. In this article, we review the contributions of major cytokines such as interferon, tumor necrosis factor-α and interleukin-18 to LE, especially SLE and CLE.

IFN-α mediates the development of autoimmunity both by direct tissue toxicity and through immune cell recruitment mechanisms

IFN-α is known to play a key role in autoimmunity, but the mechanisms are uncertain. Although the induction of autoimmunity by IFN-α is consistent with primarily immunomodulatory effects, the high frequency of nonautoimmune inflammation suggests other mechanisms. We used thyroiditis as a model to dissect these possibilities. IFN-α treatment of cultured thyrocytes increased expression of thyroid differentiation markers, thyroglobulin, thyroid-stimulating hormone receptor, thyroid peroxidase, and sodium iodide transporter. RNAseq analysis demonstrated that pathways of Ag presentation, pattern recognition receptors, and cytokines/chemokines were also stimulated. These changes were associated with markedly increased nonapoptotic thyroid cell death, suggesting direct toxicity. To corroborate these in vitro findings, we created transgenic mice with thyroid-specific overexpression of IFN-α under control of the thyroglobulin promoter. Transgenic mice developed marked inflammatory thyroid destruction associated with immune cell infiltration of thyroid and surrounding tissues leading to profound hypothyroidism, findings consistent with our in vitro results. In addition, transgenic mice thyroids showed upregulation of pathways similar to those observed in cultured thyrocytes. In particular, expression of granzyme B, CXCL10, a subset of the tripartite motif-containing family, and other genes involved in recruitment of bystander cytotoxic immune responses were increased. Pathways associated with apoptosis and autophagy were not induced. Taken together, our data demonstrate that the induction of tissue inflammation and autoimmunity by IFN-α involves direct tissue toxic effects as well as provocation of destructive bystander immune responses.

Increased expression of guanylate binding protein-1 in lesional skin of patients with cutaneous lupus erythematosus

The large GTPase human guanylate binding protein-1 (GBP-1) is a key mediator of angiostatic effects of inflammation and is induced by interferon (IFN)-α and IFN-γ in endothelial cells (ECs). The aim of this study was to investigate whether GBP-1 is a marker of skin lesions in patients with cutaneous lupus erythematosus (CLE). Western blotting revealed that GBP-1 was in vitro induced by IFN-α and -γ in primary keratinocytes obtained from healthy controls. Moreover, we found that this protein was expressed by keratinocytes and ECs in primary and ultraviolet (UV)-induced skin lesions from patients with various subtypes of CLE, when compared to non-lesional skin. No GBP-1 expression was noted in skin biopsy specimens 24 or 72 h after UV irradiation prior to lesion formation in patients with CLE or in healthy control specimens with or without UV irradiation. Initial findings suggest that GBP-1 is not expressed in other skin diseases with different inflammatory aetiology, such as atopic dermatitis. We conclude that GBP-1 expression is closely associated with skin lesions in patients with CLE, suggesting a contribution of GBP-1 in the pathogenesis of this disease.

Overview of common, rare and atypical manifestations of cutaneous lupus erythematosus and histopathological correlates

The skin is the second most frequently affected organ system in lupus erythematosus. Although only very rarely life threatening--an example is lupus erythematosus-associated toxic epidermal necrolysis--skin disease contributes disproportionally to disease burden in terms of personal and psychosocial wellbeing, vocational disability, and hence in medical and social costs. Since several manifestations are closely associated with the presence and activity of systemic lupus erythematosus, prompt and accurate diagnosis of cutaneous lupus erythematosus is essential. This review aims to cover common, rare, and atypical manifestations of lupus erythematosus-associated skin disease with a detailed discussion of histopathological correlates. Cutaneous lupus erythematosus covers a wide morphological spectrum well beyond acute, subacute and chronic cutaneous lupus erythematosus, which are commonly classified as lupus-specific skin disease. Other uncommon or less well-known manifestations include lupus erythematosus tumidus, lupus profundus, chilblain lupus, mucosal lupus erythematosus, and bullous lupus erythematosus. Vascular manifestations include leukocytoclastic and urticarial vasculitis, livedoid vasculopathy and livedo reticularis/ racemosa. Finally, we discuss rare presentations such as lupus erythematosus-related erythema exsudativum multiforme (Rowell syndrome), Kikuchi-Fujimoto disease, extravascular necrotizing palisaded granulomatous dermatitis (Winkelmann granuloma), and neutrophilic urticarial dermatosis.

Activation of the interferon pathway in peripheral blood of patients with Sjogren's syndrome

OBJECTIVE

DNA microarray analysis and quantitative real-time polymerase chain reaction (PCR) were performed to identify key target genes in peripheral blood from patients with Sjögren's syndrome (SS).

METHODS

DNA microarray analysis was performed in 19 patients with SS (all women) and 10 healthy controls (5 men and 5 women) using a low-density DNA microarray system with 778 genes. For confirmation, the expression of upregulated genes was analyzed by quantitative real-time PCR in another 37 SS patients (35 women and 2 men) and 9 healthy controls (8 women and 1 man). Relationships between gene signatures and various clinical measures, such as disease duration, symptoms and signs, complications, immunological findings, and salivary and lacrimal functions, were analyzed.

RESULTS

Interferon-α (IFN-α)-inducible protein 27 (IFI27) showed the most significant difference between SS patients and controls in the microarray screening. We performed quantitative RT-PCR for IFI27. IFI27 gene expression level was increased in patients with SS compared with controls (p < 0.01) by real-time PCR, supporting our observations from the microarray data. The level of IFI27 was significantly correlated with serum IgG levels (r = 0.462, p < 0.01) and ß(2)-microglobulin (r = 0.385, p < 0.05), soluble interleukin 2 receptor (r = 0.473, p < 0.01), erythrocyte sedimentation rate (r = 0.333, p < 0.05), and antinuclear antibody titer (speckled pattern; r = 0.445, p < 0.01).

CONCLUSION

Our results suggest that upregulation of IFN-inducible genes in SS patients is a systemic phenomenon, and IFN may play an important role in the pathogenesis of SS. The expression level of IFI27 could be an effective and specific biomarker associated with SS.

The pathogenesis of primary cicatricial alopecias

Cicatricial (scarring) alopecia results from irreversible damage to epithelial stem cells located in the bulge region of the hair follicle, generally as a result of inflammatory mechanisms (eg, in the context of autoimmune disease). In primary cicactricial alopecia (PCA), the hair follicle itself is the key target of autoaggressive immunity. This group of permanent hair loss disorders can be classified into distinct subgroups, characterized by the predominant peri-follicular inflammatory cell type. In none of these PCA forms do we know exactly why hair follicles begin to attract such an infiltrate. Thus, it is not surprising that halting or even reversing this inflammation in PCA is often extremely difficult. However, increasing evidence suggests that healthy hair follicle epithelial stem cells enjoy relative protection from inflammatory assault by being located in an immunologically "privileged" niche. Because this protection may collapse in PCA, one key challenge in PCA research is to identify the specific signaling pathways that endanger, or restore, the relative immunoprotection of these stem cells. After a summary of pathobiological principles that underlie the development and clinical phenotype of PCA, we close by defining key open questions that need to be answered if more effective treatment modalities for this therapeutically very frustrating, but biologically fascinating, group of diseases are to be developed.

Chikungunya virus arthritis in adult wild-type mice

Chikungunya virus is a mosquito-borne arthrogenic alphavirus that has recently reemerged to produce the largest epidemic ever documented for this virus. Here we describe a new adult wild-type mouse model of chikungunya virus arthritis, which recapitulates the self-limiting arthritis, tenosynovitis, and myositis seen in humans. Rheumatic disease was associated with a prolific infiltrate of monocytes, macrophages, and NK cells and the production of monocyte chemoattractant protein 1 (MCP-1), tumor necrosis factor alpha (TNF-alpha), and gamma interferon (IFN-gamma). Infection with a virus isolate from the recent Reunion Island epidemic induced significantly more mononuclear infiltrates, proinflammatory mediators, and foot swelling than did an Asian isolate from the 1960s. Primary mouse macrophages were shown to be productively infected with chikungunya virus; however, the depletion of macrophages ameliorated rheumatic disease and prolonged the viremia. Only 1 microg of an unadjuvanted, inactivated, whole-virus vaccine derived from the Asian isolate completely protected against viremia and arthritis induced by the Reunion Island isolate, illustrating that protection is not strain specific and that low levels of immunity are sufficient to mediate protection. IFN-alpha treatment was able to prevent arthritis only if given before infection, suggesting that IFN-alpha is not a viable therapy. Prior infection with Ross River virus, a related arthrogenic alphavirus, and anti-Ross River virus antibodies protected mice against chikungunya virus disease, suggesting that individuals previously exposed to Ross River virus should be protected from chikungunya virus disease. This new mouse model of chikungunya virus disease thus provides insights into pathogenesis and a simple and convenient system to test potential new interventions.

Lupus serum IgG induces skin inflammation through the TNFR1 signaling pathway

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by high autoantibody levels and multiorgan tissue damage, including kidney and skin. Cutaneous manifestations are frequent in patients with SLE, yet the etiology and pathogenesis of skin injury in SLE remains unclear. We reasoned that lupus serum containing high levels of autoreactive Ig contributes to skin injury. In this article, we report that serum from SLE patients and lupus-prone mice induces skin inflammation following intradermal injection into normal mice. Lupus serum depleted of IgG failed to cause skin inflammation. Monocytes, but not lymphocytes, were found to be crucial in the development of lupus serum-induced skin inflammation, and lupus serum IgG induced monocyte differentiation into dendritic cells (DCs). TNF-alpha and TNFR1, but not TNFR2, were required for the development of lupus serum-induced skin inflammation. TNFR1, not TNFR2, represented the main molecule expressed in the skin lesions caused by injected lupus serum. Our studies demonstrated that lupus serum IgG causes skin injury by involving the TNFR1 signaling pathway and monocyte differentiation to DCs. Accordingly, disruption of the TNFR1-mediated signaling pathway and blockade of DC generation may prove to be of therapeutic value in patients with cutaneous lupus erythematosus.

Safety, Tolerability, and Immunogenicity of Interferons

Interferons (IFNs) are class II cytokines that are key components of the innate immune response to virus infection. Three IFN sub-families, type I, II, and III IFNs have been identified in man, Recombinant analogues of type I IFNs, in particular IFNα2 and IFNβ1, have found wide application for the treatment of chronic viral hepatitis and remitting relapsing multiple sclerosis respectively. Type II IFN, or IFN gamma, is used principally for the treatment of chronic granulomatous disease, while the recently discovered type III IFNs, also known as IFN lambda or IL-28/29, are currently being evaluated for the treatment of chronic viral hepatitis. IFNs are in general well tolerated and the most common adverse events observed with IFNα or IFNβ therapy are “flu-like” symptoms such as fever, headache, chills, and myalgia. Prolonged treatment is associated with more serious adverse events including leucopenia, thrombocytopenia, increased hepatic transaminases, and neuropsychiatric effects. Type I IFNs bind to high-affinity cell surface receptors, composed of two transmembrane polypeptides IFNAR1 and IFNAR2, resulting in activation of the Janus kinases Jak1 and Tyk2, phosphorylation and activation of the latent cytoplasmic signal transducers and activators of transcription (STAT1) and STAT2, formation of a transcription complex together with IRF9, and activation of a specific set of genes that encode the effector molecules responsible for mediating the biological activities of type I IFNs. Systemic administration of type I IFN results in activation of IFN receptors present on essentially all types of nucleated cells, including neurons and hematopoietic stem cells, in addition to target cells. This may well explain the wide spectrum of IFN associated toxicities. Recent reports suggest that certain polymorphisms in type I IFN signaling molecules are associated with IFN-induced neutropenia and thrombocytopenia in patients with chronic hepatitis C. IFNγ binds to a cell-surface receptor composed of two transmembrane polypeptides IFGR1 and IFGR2 resulting in activation of the Janus kinases Jak1 and Jak2, phosphorylation of STAT1, formation of STAT1 homodimers, and activation of a specific set of genes that encode the effector molecules responsible for mediating its biological activity. In common with type I IFNs, IFNγ receptors are ubiquitous and a number of the genes activated by IFNγ are also activated by type I IFNs that may well account for a spectrum of toxicities similar to that associated with type I IFNs including “flu-like” symptoms, neutropenia, thrombocytopenia, and increased hepatic transaminases. Although type III IFNs share the major components of the signal transduction pathway and activate a similar set of IFN-stimulated genes (ISGs) as type I IFNs, distribution of the IFNλ receptor is restricted to certain cell types suggesting that IFNλ therapy may be associated with a reduced spectrum of toxicities relative to type I or type II IFNs. Repeated administration of recombinant IFNs can cause in a break in immune tolerance to self-antigens in some patients resulting in the production of neutralizing antibodies (NABs) to the recombinant protein homologue. Appearance of NABs is associated with reduced pharmacokinetics, pharmacodynamics, and a reduced clinical response. The lack of cross-neutralization of IFNβ by anti-IFNα NABs and vice versa, undoubtedly accounts for the apparent lack of toxicity associated with the presence of anti-IFN NABs with the exception of relatively mild infusion/injection reactions.

Hepatitis B virus protein X-induced expression of the CXC chemokine IP-10 is mediated through activation of NF-kappaB and increases migration of leukocytes

Interferon-gamma inducible protein 10 (IP-10) involves inflammatory cell recruitment and cellular immune damage during virus infection. Although an increase of the peripheral IP-10 level is known in HBV-infected patients, the molecular basis of HBV infection inducing IP-10 expression has remained elusive. In the present study, we demonstrate that hepatitis B virus protein X (HBx) increases IP-10 expression in a dose-dependent manner. Transfection of the HBx-expressing vector into HepG2 cells results in nuclear translocation of NF-kappaB, which directly binds the promoter of IP-10 at positions from -122 to -113, thus facilitating transcription. The addition of the NF-kappaB inhibitor blocks the effect of HBx on IP-10 induction. In parallel, increase of NF-kappaB subunits p65 and p50 in HepG2 cells also augments IP-10 expression. Furthermore, we show that HBx induces activation of NF-kappaB through the TRAF2/TAK1 signaling pathway, leading to up-regulation of IP-10 expression. As a consequence, up-regulation of IP-10 may mediate the migration of peripheral blood leukocytes in a NF-kappaB-dependent manner. In conclusion, we report a novel molecular mechanism of HBV infection inducing IP-10 expression, which involves viral protein HBx affecting NF-kappaB pathway, leading to transactivation of the IP-10 promoter. Our study provides insight into the migration of leukocytes in response to HBV infection, thus causing immune pathological injury of liver.

Cytokine networks in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease more prominent in women and characterized by multiple organ damage. Imbalance in cytokine production and cytokine levels correlates with SLE progression, making the understanding of SLE cytokine networks very important for SLE treatment strategy and drug development. In this article, we review cytokine networks that may be involved in the pathogenesis of SLE by briefly describing abnormal cytokine production and serum cytokine levels in SLE patients. We also focus on the pathological roles of cytokines and their interactions in immunoregulatory networks and suggest how their disturbances may implicate in pathological conditions in SLE. Finally, we further discuss the influence of estrogen on these cytokine networks.

Cutaneous lupus erythematosus: issues in diagnosis and treatment

Cutaneous lupus erythematosus (LE) may present in a variety of clinical forms. Three recognized subtypes of cutaneous LE are acute cutaneous LE (ACLE), subacute cutaneous LE (SCLE), and chronic cutaneous LE (CCLE). ACLE may be localized (most often as a malar or 'butterfly' rash) or generalized. Multisystem involvement as a component of systemic LE (SLE) is common, with prominent musculoskeletal symptoms. SCLE is highly photosensitive, with predominant distribution on the upper back, shoulders, neck, and anterior chest. SCLE is frequently associated with positive anti-Ro antibodies and may be induced by a variety of medications. Classic discoid LE is the most common form of CCLE, with indurated scaly plaques on the scalp, face, and ears, with characteristic scarring and pigmentary change. Less common forms of CCLE include hyperkeratotic LE, lupus tumidus, lupus profundus, and chilblain lupus. Common cutaneous disease associated with, but not specific for, LE includes vasculitis, livedo reticularis, alopecia, digital manifestations such as periungual telangiectasia and Raynaud phenomenon, photosensitivity, and bullous lesions. The clinical presentation of each of these forms, their diagnosis, and the inter-relationships between cutaneous LE and SLE are discussed. Common systemic findings in SLE are reviewed, as are diagnostic strategies, including histopathology, immunopathology, serology, and other laboratory findings. Treatments for cutaneous LE initially include preventive (e.g. photoprotective) strategies and topical therapies (corticosteroids and topical calcineurin inhibitors). For skin disease not controlled with these interventions, oral antimalarial agents (most commonly hydroxychloroquine) are often beneficial. Additional systemic therapies may be subdivided into conventional treatments (including corticosteroids, methotrexate, thalidomide, retinoids, dapsone, and azathioprine) and newer immunomodulatory therapies (including efalizumab, anti-tumor necrosis factor agents, intravenous immunoglobulin, and rituximab). We review evidence for the use of these medications in the treatment of cutaneous LE.