Interleukin-20 as a target in psoriasis treatment

The effect of interleukin-20 on periodontal tissue destruction in individuals with periodontitis

BACKGROUND AND OBJECTIVE

Periodontitis is an inflammatory disease that destroys periodontal tissues. Interleukin-20 (IL-20), on the other hand, is known as a potent angiogenic, chemotactic, and pro-inflammatory cytokine associated with various chronic inflammatory disorders. IL-20 has a significant role in the regulation of osteoclastogenesis and osteoblastogenesis. This study aimed to evaluate the effect of IL-20 on periodontal destruction.

METHODS

In this study, a total of 60 participants were included, 30 of whom were systemically and periodontally healthy (control group), and 30 were systemically healthy but had periodontitis (periodontitis group). Gingival crevicular fluid (GCF) and serum samples were collected from the participants for biochemical analysis. Enzyme-linked immunosorbent assay was used to determine the levels of IL-20, tumor necrosis factor (TNF)-α, IL1β/IL-10, RANKL/osteoprotegerin (OPG), and matrix metalloproteinase-8 (MMP8). For statistical analysis, the independent t-test, Pearson correlation coefficients, and the Chi-square test were used.

RESULTS

GCF IL-20, RANKL, RANKL/OPG, serum IL-20, RANKL, RANKL/OPG, MMP-8, TNF-α, IL-1B, and IL-1β/IL-10 values were found to be statistically significantly higher in the periodontitis group than in the control group. GCF OPG and serum IL-10 values were found to be statistically significantly higher in the control group than in the periodontitis group. No statistically significant difference was observed between the groups in serum OPG values. A statistically significantly positive correlation was observed between serum IL-20 value and serum RANKL, RANKL/OPG, MMP-8, TNF-α, IL-1β values, and periodontal clinical parameters. The ROC curves showed: AUC = 0.788 for GCF IL-20, and AUC = 1.000 for serum IL-20.

CONCLUSION

According to the results of the study, IL-20 was found to be associated with periodontitis. The role of IL-20 in periodontal pathogenesis is related to osteoclastogenesis and collagen degradation. It is conceivable that IL-20 may increase bone destruction by both affecting the RANKL/OPG ratio and proinflammatory cytokines.

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.

Interleukin-10 family members: Biology and role in the bone and joint diseases

Interleukin (IL)-10 family cytokines include IL-10, IL-19, IL-20, IL-22, IL-24, IL-26, IL-28A, IL-28B, and IL-29. These cytokines play crucial regulatory roles in various biological reactions and diseases. In recent years, several studies have shown that the IL-10 family plays a vital role in bone and joint diseases, including bone metabolic diseases, fractures, osteoarthritis, rheumatoid arthritis, and bone tumors. Herein, the recent progress on the regulatory role of IL-10 family of cytokines in the occurrence and development of bone and joint diseases has been summarized. This review will provide novel directions for immunotherapy of bone and joint diseases.

Roles of IL-1 and IL-10 family cytokines in the progression of systemic lupus erythematosus: Friends or foes?

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease of unknown etiology that can affect nearly every organ system in the body. Besides genetic and environmental factors, unbalanced pro-inflammatory and anti-inflammatory cytokines contribute to immune dysregulation, trigger an inflammatory response, and induce tissue and organ damage. Inflammatory responses in SLE can be promoted and/or maintained by the availability of cytokines that are overproduced systemically and/or in local tissues. Several key cytokines have been considered potential targets for the reduction of chronic inflammation in SLE. Recent studies indicated that dysregulated production of several cytokines, including those of the IL-1 family and IL-10 family, orchestrate immune activation and self-tolerance, play critical roles in the pathogenesis of SLE. Among IL-1 family cytokines, IL-1, IL-18, IL-33, IL-36, IL-37, and IL-38 had been the most thoroughly investigated in SLE. Additionally, IL-10 family cytokines, IL-10, IL-20, IL-22, IL-26, IL-28, and IL-29 are dysregulated in SLE. Therefore, a better understanding of the initiation and progression of SLE may provide suitable novel targets for therapeutic intervention. In this review, we discuss the involvement of inflammation in the pathogenesis of SLE, with a focus on IL-1 family and IL-10 family cytokines, and highlight pathophysiological approaches and therapeutic potential for treating SLE.

Interleukin-18, interleukin-20, and matrix metalloproteinases (MMP-1, MMP-3) as markers of psoriatic arthritis disease severity and their correlations with biomarkers of inflammation and turnover of joint cartilage

Introduction

Psoriatic arthritis (PsA) is a chronic, seronegative spondyloarthropathy characterised by joint inflammation and psoriatic skin changes. Recent data indicate that interleukin-18 (IL-18) and interleukin-20 (IL-20) may be involved in the aetiopathogenesis of PsA.

Aim

To evaluate the potential role of IL-18, IL-20, and matrix metalloproteinases (MMP-1, MMP-3) in the pathogenesis of PsA and their correlations with other markers of inflammation and destruction of joint cartilage, as well as clinical changes.

Material and methods

The study included 24 patients with PsA and 26 healthy volunteers as a control group. The concentration of IL-18 and IL-20, c-reactive protein (CRP), metalloproteinase-1 and -3 (MMP-1, MMP-3), cartilage oligomeric matrix protein (COMP), aggrecan (PG-AG), and human cartilage glycoprotein (YKL-40) in serum was determined. Clinical severity of the disease according to the BSA, PASI, and DLQI as well as tender and swollen joint count (TJC, SJC) were also evaluated.

Results

The concentration of IL-18 was statistically significantly higher in the serum of patients with PsA than in the control group (62.87 pg/ml vs. 16.73 pg/ml, p < 0.0049). Serum IL-20 levels in PsA patients were also higher than in the control group, but without statistical significance (p = 0.2939). The ROC curves showed: AUC = 0.81 for IL-18, AUC = 0.75 for IL-20, AUC = 0.96 for COMP, and AUC = 0.89 for MMP-3.

Conclusions

IL-18 and IL-20 as well as MMP-3 and COMP may be sensitive markers in the diagnosis of PsA.

IL-20 in Acute Kidney Injury: Role in Pathogenesis and Potential as a Therapeutic Target

Acute kidney injury (AKI) causes over 1 million deaths worldwide every year. AKI is now recognized as a major risk factor in the development and progression of chronic kidney disease (CKD). Diabetes is the main cause of CKD as well. Renal fibrosis and inflammation are hallmarks in kidney diseases. Various cytokines contribute to the progression of renal diseases; thus, many drugs that specifically block cytokine function are designed for disease amelioration. Numerous studies showed IL-20 functions as a pro-inflammatory mediator to regulate cytokine expression in several inflammation-mediated diseases. In this review, we will outline the effects of pro-inflammatory cytokines in the pathogenesis of AKI and CKD. We also discuss the role of IL-20 in kidney diseases and provide a potential therapeutic approach of IL-20 blockade for treating renal diseases.

A Platform for Extracellular Interactome Discovery Identifies Novel Functional Binding Partners for the Immune Receptors B7-H3/CD276 and PVR/CD155

Receptors expressed on the plasma membrane and their interacting partners critically regulate cellular communication during homeostasis and disease, and as such represent main therapeutic targets. Despite its importance for drug development, receptor-ligand proteomics has remained a daunting field, in part because of the challenges associated to the study of membrane-expressed proteins. Here, to enable sensitive detection of receptor-ligand interactions in high throughput, we implement a new platform, the Conditioned Media AlphaScreen, for interrogation of a library consisting of most single transmembrane human proteins. Using this method to study key immune receptors, we identify and further validate the interleukin receptor IL20RA as the first binding partner for the checkpoint inhibitor B7-H3. Further, KIR2DL5, a natural killer cell protein that had remained orphan, is uncovered as a functional binding partner for the poliovirus receptor (PVR). This interaction is characterized using orthogonal assays, which demonstrate that PVR specifically engages KIR2DL5 on natural killer cells leading to inhibition of cytotoxicity. Altogether, these results reveal unappreciated links between protein families that may importantly influence receptor-driven functions during disease. Applicable to any target of interest, this technology represents a versatile and powerful approach for elucidation of receptor-ligand interactomes, which is essential to understand basic aspects of the biology of the plasma membrane proteins and ultimately inform the development of novel therapeutic strategies.

Combining Understanding of Immunological Mechanisms and Genetic Variants Toward Development of Personalized Medicine for Psoriasis Patients

Psoriasis is multifactorial disease with complex genetic predisposition. Recent advances in genetics and genomics analyses have provided many insights into the relationship between specific genetic predisposition and the immunopathological mechanisms driving psoriasis manifestation. Novel approaches which utilize array-based genotyping technologies such as genome-wide association studies and bioinformatics tools for transcriptomics analysis have identified single nucleotide polymorphisms, genes and pathways that are associated with psoriasis. The discovery of these psoriasis-associated susceptibility loci, autoimmune targets and altered signaling pathways have provided opportunities to bridge the gap of knowledge from sequence to consequence, allowing new therapeutic strategies for the treatment of psoriasis to be developed. Here, we discuss recent advances in the field by highlighting how immune functions associated with psoriasis susceptibility loci may contribute to disease pathogenesis in different populations. Understanding the genetic variations in psoriasis and how these may influence the immunological pathways to cause disease will contribute to the efforts in developing novel and targeted personalized therapies for psoriasis patients.

The role of IL-20 in chronic kidney disease and diabetic nephropathy: Pathogenic and therapeutic implications

Chronic kidney disease and its complications are a major public health problem worldwide. Diabetic nephropathy has become the main contributing cause of terminal renal failure. There are now evidences that different inflammatory molecules, including proinflammatory cytokines, play a critical role in the development of microvascular diabetic complications, including nephropathy. IL-20 is emerging as a potent angiogenic, chemotactic, and proinflammatory cytokine related to several chronic inflammatory disorders likes psoriasis, atherosclerosis, and renal failure. This review discusses the role of IL-20 as a pathogenic factor in renal injury, focusing on chronic kidney disease and diabetic nephropathy, and describes potential treatment strategies based on modulation of IL-20's function.

Psoriasis Treatments: A Review of the Current Research Pipeline

Psoriasis treatment is aimed at suppressing skin lesions and preventing relapses. Although in the last decade biological therapies have revolutionized the pharmacologic treatment armamentarium for psoriasis, many patients are still inadequately controlled with currently available therapeutics. An advanced understanding of the immunopathogensis of psoriasis has led to development of new drugs that refine existing treatments or target novel molecular and immunologic pathways. Here we review the most promising topical, oral, and injectable psoriasis treatments in the research pipeline, including agents that target cytokines interleukin (IL)-12/23, tumor necrosis factor-α, IL-20, IL-17, IL-22, inhibitors of calcineurin, phosphodiesterase type 4, protein kinase C, Janus kinase, p38 kinase, purine nucleotide phosphorylase, adenosine receptor agonists, and recombinant chaperonin protein. These targeted therapeutics offer the potential for greater clinical efficacy and less toxicity than traditional agents. As the number of treatment options continues to expand, clinicians will have more diverse opportunities to help patients achieve better psoriasis control.

IL-20 bone diseases involvement and therapeutic target potential

BACKGROUND

Millions of people around the world suffer from bone disorders, likes osteoporosis, rheumatoid arthritis (RA), and cancer-induced osteolysis. In general, the bone remodeling balance is determined by osteoclasts and osteoblasts, respectively responsible for bone resorption and bone formation. Excessive inflammation disturbs the activities of these two kinds of cells, typically resulting in the bone loss.

MAIN BODY

IL-20 is emerging as a potent angiogenic, chemotactic, and proinflammatory cytokine related to several chronic inflammatory disorders likes psoriasis, atherosclerosis, cancer, liver fibrosis, and RA. IL-20 has an important role in the regulation of osteoclastogenesis and osteoblastogenesis and is upregulated in several bone-related diseases. The anti-IL-20 monoclonal antibody treatment has a therapeutic potential in several experimental disease models including ovariectomy-induced osteoporosis, cancer-induced osteolysis, and bone fracture.

CONCLUSION

This review article provides an overview describing the IL-20's biological functions in the common bone disorders and thus providing a novel therapeutic strategy in the future.

Elevated Gene Expression of Interleukin-32 Isoforms Alpha, Beta, Gamma, and Delta in the Peripheral Blood of Chronic Psoriatic Patients

Inflammatory-mediated reactions have been implicated as contributors in a number of dermatological disorders, including psoriasis. However, the potential of interleukin (IL)-32 and its isoforms to contribute to the pathogenesis of psoriasis remains unexplored. This study was undertaken to investigate the role of IL-32 and its isoforms IL-32α, IL-32β, IL-32γ, and IL-32δ in the peripheral blood of psoriatic patients. The majority of chronic plaque psoriatic patients showed elevated IL-32 mRNA levels in the peripheral blood mononuclear cells (PBMCs) as compared with the levels of IL-32 mRNA in PBMCs of healthy controls (p = 0.001). To further investigate the role of elevated levels of IL-32 in psoriatic patients, IL-32 isoforms mRNAs were determined. All tested isoforms IL-32α, IL-32β, IL-32γ, and IL-32δ were overexpressed in psoriatic patients PBMCs as compared with healthy controls’ PBMCs (p < 0.05). IL-32α mRNA expression was also significantly higher as compared with all other isoforms of IL-32 in PBMCs of psoriatic patients (p < 0.001). In short, this is the first study that shows the role of IL-32 and its isoforms in the peripheral blood of psoriatic patients. Our novel findings support an association between elevated levels of IL-32 and psoriasis. The data also suggest that a major proinflammatory response of IL-32 may derive from IL-32α isoform in psoriasis.

Interleukin-20 promotes airway remodeling in asthma

Previous studies have demonstrated that interleukin-20 (IL-20) is a pro-inflammatory cytokine, and it has been implicated in psoriasis, lupus nephritis, rheumatoid arthritis, atherosclerosis, and ulcerative colitis. Little is known about the effects of IL-20 in airway remodeling in asthma. The aim of our study was to demonstrate the function of IL-20 in airway remodeling in asthma. To identify the expression of IL-20 and its receptor, IL-20R1/IL-20R2, in the airway epithelium in bronchial tissues, bronchial biopsy specimens were collected from patients and mice with asthma and healthy subjects and stained with specific antibodies. To characterize the effects of IL-20 in asthmatic airway remodeling, we silenced and stimulated IL-20 in cell lines isolated from mice by shRNA and recombinant protein approaches, respectively, and detected the expression of α-SMA and FN-1 by Western blot analysis. First, overexpression of IL-20 and its receptor, IL-20R1/IL-20R2, was detected in the airway epithelium collected from patients and mice with asthma. Second, IL-20 increased the expression of fibronectin-1 and α-SMA, and silencing of IL-20 in mouse lung epithelial (MLE)-12 cells decreased the expression of fibronectin-1 and α-SMA. IL-20 may be a critical cytokine in airway remodeling in asthma. This study indicates that targeting IL-20 and/or its receptors may be a new therapeutic strategy for asthma.

Reduction of IL-20 Expression in Rheumatoid Arthritis by Linear Polarized Infrared Light Irradiation

BACKGROUND

Low-level laser is being evaluated for treating rheumatoid arthritis (RA). Recently, the linear polarized infrared light (Super Lizer, SL) irradiation may also be useful for RA treatment. However, the molecular mechanism underlying the effectiveness of SL on RA is unclear. It has been IL-20 may involved in RA disease progression.

AIM

To understand how SL action, we constructed the experimental model in vitro using human rheumatoid fibroblast-like synoviocyte (MH7A) and collagen induced (CIA) RA rat in vivo. We examined the effect of SL irradiation on IL-20 gene expression in MH7A and IL-20 protein production in CIA) rat joints.

MATERIALS AND METHODS

MH7A was cultured and challenged with IL-1ß, then examined IL-20 and IL-20R mRNA level by DNA microarray. IL-20 protein expression was examined by immunohistochemistry using a specific antibody against rat IL-20.

RESULT

Scatter plot analysis demonstrated that an increase in IL-20 gene expression by IL-1ß was reduced by SL irradiation, but IL-20R did not show a significant change. The Immunohistochemical analysis demonstrated a strong IL-20 staining in synovial membrane tissue of CIA rat joint, and SL irradiation significantly reduced the staining.

DISCUSSION

Since IL-20 has been identified as an important cytokine in the pathogenesis of RA, the reduction of IL-20 expression by SL irradiation may be one of mechanisms in reduction of inflammation in RA joints by SL irradiation suggesting that SL irradiation may be useful for RA therapy.

The Therapeutic Potential of Anti-Interleukin-20 Monoclonal Antibody

Interleukin (IL)-20, a member of the IL-10 family of cytokines, was discovered in 2001. IL-20 acts on multiple cell types by activating on a heterodimer receptor complex of either IL-20R1–IL-20R2 or IL-22R1–IL-20R2. Recent evidence indicates that IL-20's interaction with its receptors might have proinflammatory effects on chronic inflammatory diseases, particularly rheumatoid arthritis (RA), osteoporosis, and breast cancer. Updated information about IL-20, such as its identification, expression, receptors, signaling, and biological activities, is illustrated in this review based on our research and the data available in the literature. IL-20 is a pleiotropic cytokine, which promotes inflammation, angiogenesis, and chemotaxis. IL-20 also regulates osteoclast differentiation by altering the receptor activator of NF-κB (RANK) and RANK ligand (RANKL) axis. Inflammation, angiogenesis, and osteoclastogenesis are critical for the pathogenesis of RA, osteoporosis, and breast cancer-induced osteolysis. Based on the in vitro and in vivo data and clinical samples, we demonstrated that IL-20 plays pivotal roles in these three diseases. In experimental models, anti-IL-20 monoclonal antibody ameliorates arthritis severity, protects against ovariectomized-induced bone loss, and inhibits breast tumor-induced osteolysis. This review presents the clinical implications of IL-20, which will lead to a better understanding of the biological functions of IL-20 in these diseases and provide new therapeutic options in the future.

Expression of IL-20 in synovium and lesional skin of patients with psoriatic arthritis: differential response to alefacept treatment

Introduction

Psoriatic arthritis (PsA) is an inflammatory joint disease associated with psoriasis. Alefacept (a lymphocyte function-associated antigen (LFA)-3 Ig fusion protein that binds to CD2 and functions as an antagonist to T-cell activation) has been shown to result in improvement in psoriasis but has limited effectiveness in PsA. Interleukin-20 (IL-20) is a key proinflammatory cytokine involved in the pathogenesis of psoriasis. The effects of alefacept treatment on IL-20 expression in the synovium of patients with psoriasis and PsA are currently unknown.

Methods

Eleven patients with active PsA and chronic plaque psoriasis were treated with alefacept (7.5 mg per week for 12 weeks) in an open-label study. Skin biopsies were taken before and after 1 and 6 weeks, whereas synovial biopsies were obtained before and 4 and 12 weeks after treatment. Synovial biopsies from patients with rheumatoid arthritis (RA) (n = 10) were used as disease controls. Immunohistochemical analysis was performed to detect IL-20 expression, and stained synovial tissue sections were evaluated with digital image analysis. Double staining was performed with IL-20 and CD68 (macrophages), and conversely with CD55 (fibroblast-like synoviocytes, FLSs) to determine the phenotype of IL-20-positive cells in PsA synovium. IL-20 expression in skin sections (n = 6) was analyzed semiquantitatively.

Results

IL-20 was abundantly expressed in both PsA and RA synovial tissues. In inflamed PsA synovium, CD68⁺ macrophages and CD55⁺ FLSs coexpressed IL-20, and its expression correlated with the numbers of FLSs. IL-20 expression in lesional skin of PsA patients decreased significantly (P = 0.04) 6 weeks after treatment and correlated positively with the Psoriasis Area and Severity Index (PASI). IL-20 expression in PsA synovium was not affected by alefacept.

Conclusions

Conceivably, the relatively limited effectiveness of alefacept in PsA patients (compared with anti-tumor necrosis factor (TNF) therapy) might be explained in part by persistent FLS-derived IL-20 expression.

Dysregulation of suppressor of cytokine signaling 3 in keratinocytes causes skin inflammation mediated by interleukin-20 receptor-related cytokines

Homeostatic regulation of epidermal keratinocytes is controlled by the local cytokine milieu. However, a role for suppressor of cytokine signaling (SOCS), a negative feedback regulator of cytokine networks, in skin homeostasis remains unclear. Keratinocyte specific deletion of Socs3 (Socs3 cKO) caused severe skin inflammation with hyper-production of IgE, epidermal hyperplasia, and S100A8/9 expression, although Socs1 deletion caused no inflammation. The inflamed skin showed constitutive STAT3 activation and up-regulation of IL-6 and IL-20 receptor (IL-20R) related cytokines, IL-19, IL-20 and IL-24. Disease development was rescued by deletion of the Il6 gene, but not by the deletion of Il23, Il4r, or Rag1 genes. The expression of IL-6 in Socs3 cKO keratinocytes increased expression of IL-20R-related cytokines that further facilitated STAT3 hyperactivation, epidermal hyperplasia and neutrophilia. These results demonstrate that skin homeostasis is strictly regulated by the IL-6-STAT3-SOCS3 axis. Moreover, the SOCS3-mediated negative feedback loop in keratinocytes has a critical mechanistic role in the prevention of skin inflammation caused by hyperactivation of STAT3.

Histamine induces human beta-defensin-3 production in human keratinocytes

BACKGROUND

The antimicrobial peptide human beta-defensin-3 (hBD-3) is produced by epidermal keratinocytes, and promotes cutaneous antimicrobial defense, inflammation, and wound repair. hBD-3 induces histamine release from mast cells. We previously showed that histamine enhanced transcriptional activity of activator protein-1 (AP-1) in human keratinocytes by inducing the expression of AP-1 component c-Fos via the activation of extracellular signal-regulated kinase (ERK) through H1 receptors.

OBJECTIVE

To examine in vitro effects of histamine on hBD-3 production in normal human keratinocytes.

METHODS

The hBD-3 production was examined by enzyme-linked immunosorbent assays and reverse transcription-polymerase chain reaction. The transcriptional activities were analyzed by dual luciferase assays. The phosphorylation of proteins was examined by Western blotting.

RESULTS

Histamine enhanced hBD-3 secretion and mRNA expression in keratinocytes. The histamine-induced hBD-3 production was suppressed by H1 antagonist pyrilamine and antisense oligonucleotides against signal transducer and activator of transcription 3 (STAT3) and AP-1 components c-Jun and c-Fos. Histamine enhanced STAT3 transcriptional activity and induced tyrosine and serine phosphorylation of STAT3. The former was suppressed by Janus kinase 2 (JAK2) inhibitor AG490, while the latter was suppressed by mitogen-activated protein kinase kinase (MEK) inhibitor PD98059; both were suppressed by pyrilamine. AG490 and PD98059 suppressed histamine-induced hBD-3 production and STAT3 activity. Histamine induced tyrosine phosphorylation of JAK2, and pyrilamine suppressed the phosphorylation.

CONCLUSION

It is suggested that histamine induces hBD-3 production in human keratinocytes through H1 receptors by activating STAT3 and AP-1 via JAK2 and MEK/ERK. Histamine may promote cutaneous antimicrobial defense, inflammation, and wound repair through hBD-3.

Key role of macrophages in the pathogenesis of CD18 hypomorphic murine model of psoriasis

Psoriasis is a chronic skin disorder of unsolved pathogenesis affecting skin in 2-3% of the general population. Research into the pathogenesis of psoriasis has profited from suitable animal models. Previously, we reported on the CD18 hypomorphic (CD18(hypo)) PL/J mouse model clinically resembling human psoriasis, which is characterized by reduced expression of the common chain of beta(2)-integrins (CD11/CD18) to only 2-16% of wild-type levels. Aside from common clinical and pathophysiological features shared with human psoriasis, the psoriasiform skin disease in CD18(hypo) PL/J mice also depends on the presence of CD4(+) T-cells. This review focuses on the role of activated macrophages in the pathogenesis of CD18(hypo) T-cell-mediated mouse model of psoriasis, and extends our understanding in unrestrained pathogenic T-cells whose activation may be crucial for the recruitment and activation of macrophages within skin. The findings in the CD18(hypo) PL/J model are discussed in the context of current literatures of human and other autoimmune disorders.

Evaluation of IL10, IL19 and IL20 gene polymorphisms and chronic hepatitis B infection outcome

Hepatitis B virus (HBV) infection remains a serious global health problem despite the availability of a highly effective vaccine. Approximately 5% of HBV-infected adults develop chronic hepatitis B, which may result in liver cirrhosis or hepatocellular carcinoma. Variants of interleukin-10 (IL10) have been previously associated with chronic hepatitis B infection and progression to hepatocellular carcinoma. Single nucleotide polymorphisms (SNP; n = 42) from the IL10, IL19 and IL20 gene regions were examined for an association with HBV infection outcome, either chronic or recovered, in a nested case-control study of African Americans and European Americans. Among African Americans, three nominally statistically significant SNP associations in IL10, two in IL20, and one haplotype association were observed with different HBV infection outcomes (P = 0.005-0.04). A SNP (rs1518108) in IL20 deviated significantly from Hardy-Weinberg equilibrium in African Americans, with a large excess of heterozygotes in chronic HBV-infected cases (P = 0.0006), which suggests a strong genetic effect. Among European Americans, a nominally statistically significant SNP association in IL20 and an IL20 haplotype were associated with HBV recovery (P = 0.01-0.04). These results suggest that IL10 and IL20 gene variants influence HBV infection outcome and encourage the pursuit of further studies of these cytokines in HBV pathogenesis.