Interleukin-23: as a drug target for autoimmune inflammatory diseases

Stromal fibroblasts support dendritic cells to maintain IL-23/Th17 responses after exposure to ionizing radiation

Cross talk between DCs and FBs in understanding the effects of IR in DC function.

Dendritic cell function is modulated by stromal cells, including fibroblasts. Although poorly understood, the signals delivered through this crosstalk substantially alter dendritic cell biology. This is well illustrated with release of TNF-α/IL-1β from activated dendritic cells, promoting PGE₂ secretion from stromal fibroblasts. This instructs dendritic cells to up-regulate IL-23, a key Th17-polarizing cytokine. We previously showed that ionizing radiation inhibited IL-23 production by human dendritic cells in vitro. In the present study, we investigated the hypothesis that dendritic cell-fibroblast crosstalk overcomes the suppressive effect of ionizing radiation to support appropriately polarized Th17 responses. Radiation (1–6 Gy) markedly suppressed IL-23 secretion by activated dendritic cells (P < 0.0001) without adversely impacting their viability and consequently, inhibited the generation of Th17 responses. Cytokine suppression by ionizing radiation was selective, as there was no effect on IL-1β, -6, -10, and -27 or TNF-α and only a modest (11%) decrease in IL-12p70 secretion. Coculture with fibroblasts augmented IL-23 secretion by irradiated dendritic cells and increased Th17 responses. Importantly, in contrast to dendritic cells, irradiated fibroblasts maintained their capacity to respond to TNF-α/IL-1β and produce PGE₂, thus providing the key intermediary signals for successful dendritic cell-fibroblasts crosstalk. In summary, stromal fibroblasts support Th17-polarizing cytokine production by dendritic cells that would otherwise be suppressed in an irradiated microenvironment. This has potential ramifications for understanding the immune response to local radiotherapy. These findings underscore the need to account for the impact of microenvironmental factors, including stromal cells, in understanding the control of immunity.

Consumption of star fruit juice on pro-inflammatory markers and walking distance in the community dwelling elderly

PURPOSE

This study aimed to evaluate the effect of star fruit juice supplementation on tumor necrosis factor-alpha (TNF-α), interleukin-23 (IL-23) and interleukin-2 (IL-2), nitric oxide (NO), and 6 min walking distance (6MWD) in a group of elderly individuals.

METHODS

Twenty-nine individuals (20 males, 9 females) with a mean age of 72.4±8.3 years completed this study. A two-week control period was followed by four weeks of 100g fresh star fruit juice consumption twice per day after meals.

RESULTS

Plasma TNF-α, IL-23, IL-2, NO and the 6MWD were evaluated twice during the control period (weeks 0 and 2) and once after the star fruit juice consumption (week 6).

RESULTS

The results showed that all parameters in the blood did not change significantly during the control period. After 4 weeks of star fruit juice consumption, a significant reduction in NO, TNF-α and IL-23 was found; however, there was no change in IL-2. Moreover, the 6MWD increased significantly at week 6, when compared to that at week 0 and 2. Furthermore, the results also showed a significantly positive and negative correlation of NO and TNF-α to the 6MWD, but no correlation of IL-23 and IL-2.

CONCLUSION

This preliminary study concluded that consumption of star fruit juice at 100g twice daily for one month can significantly depress the pro-inflammation cytokines: TNF-α, IL-23, and NO, while increasing walking distance. Low TNF-α and high NO also present a significant correlation to walking capacity in elderly individuals.

Dynamics of Th17 associating cytokines in Cryptosporidium parvum-infected mice

Cryptosporidium parvum commonly inhabits the intestinal tract of animals and humans and can cause acute watery diarrhea and weight loss. However, host immune responses to Cryptosporidium infections are not fully understood. IL-17 (also called IL-17A) is a pro-inflammatory cytokine of Th17 cells that plays a role in the host response to Cryptosporidium baileyi infection. The present study examined levels of IL-17-specific messenger RNA (mRNA) and Th17 associating cytokines in C. parvum-infected immune-suppressed BALB/c mice using real-time quantitative PCR (qPCR). Levels of IL-17 protein were determined by ELISA. The results showed that levels of IL-17 mRNA and Th17 cell-related cytokines, namely TGF-β, IL-6, STAT-3, RORγt, IL-22, TNF-α, and IL-23, were significantly increased (P < 0.05) in gut-associated lymphoid tissue (GALT) and spleen. IL-17 protein levels in GALT were also significantly increased (P < 0.05) after infection. The present study suggested that Th17 cells play a role in host-C. parvum interaction. These results could inform future studies of the immune response against C. parvum infection in transient immunosuppressed populations.

The role of secukinumab in the treatment of ankylosing spondylitis

Ankylosing spondylitis is a chronic inflammatory disorder involving the sacroiliac joint, spine and less frequently the peripheral joints. Nonsteroidal anti-inflammatory drugs and TNF-α inhibitors are utilized to reduce signs and symptoms. Whether these agents slow disease progression, is still debatable. Secukinumab is a fully human monoclonal antibody against IL-17 that has been studied in patients with ankylosing spondylitis with promising results. It has demonstrated improvement in signs, symptoms, patient reported outcomes and functional status and has been well tolerated. The clinical improvement is also mirrored in the improvement in sacroiliac joint magnetic resonance imaging scans.

Genetic, Epigenetic and Pharmacogenetic Aspects of Psoriasis and Psoriatic Arthritis

There is a strong familial component to psoriatic disease as well as a complex array of genetic, immunologic, and environmental factors. The dominant genetic effect is located on chromosome 6p21.3 within the major histocompatibility complex region, accounting for one-third of genetic contribution. Genome-wide association studies (GWAS) identified additional genes, including skin barrier function, innate immune response, and adaptive immune response genes. To better understand disease susceptibility and progression requires replication in larger cohorts, fine-mapping efforts, new technologies, and functional studies of genetic variants, gene-gene interactions and gene-environmental interactions. New technologies available include next-generation sequencing, copy number variation analysis, and epigenetics.

Pathophysiology of pyoderma gangrenosum (PG): an updated review

Pyoderma gangrenosum is a challenging skin condition to identify and treat because of its multifactorial pathogenesis. It is a rare cutaneous manifestation diagnosed clinically by exclusion of infection, neoplasia, thrombophilia, and other inflammatory conditions. Pathogenetic and treatment studies are scarce. Abnormalities in the function of inflammatory cytokines, the immune system, and neutrophils combined with specific genetic mutations predispose patients to develop this complex disease process. Early recognition of patients at risk for pyoderma gangrenosum, the necessity to improve its early diagnosis, and the future outlook of targeted and personalized therapies relies on the improved comprehension of the complex pathogenesis of pyoderma gangrenosum.

Intravenous immunoglobulin skews macrophages to an anti-inflammatory, IL-10-producing activation state

Intravenous Ig is used to treat autoimmune or autoinflammatory disorders, but the mechanism by which it exerts its immunosuppressive activity is not understood completely. To examine the impact of intravenous Ig on macrophages, we compared cytokine production by LPS-activated macrophages in the presence and absence of intravenous Ig. Intravenous Ig treatment induced robust production of IL-10 in response to LPS, relative to LPS stimulation alone, and reduced production of proinflammatory cytokines. This anti-inflammatory, intravenous Ig-induced activation was sustained for 24 h but could only be induced if intravenous Ig were provided within 1 h of LPS stimulation. Intravenous Ig activation led to enhanced and prolonged activation of MAPKs, Erk1/2, p38, and Erk5, and inhibition of each reduced intravenous Ig-induced IL-10 production and suppression of IL-12/23p40. IL-10 production occurred rapidly in response to intravenous Ig + LPS and was sufficient to reduce proinflammatory IL-12/23p40 production in response to LPS. IL-10 induction and reduced IL-12/23p40 production were transcriptionally regulated. IL-10 played a direct role in reducing proinflammatory cytokine production by macrophages treated with intravenous Ig + LPS, as macrophages from mice deficient in the IL-10R β chain or in IL-10 were compromised in their ability to reduce proinflammatory cytokine production. Finally, intraperitoneal injection of intravenous Ig or intravenous Ig + LPS into mice activated macrophages to produce high levels of IL-10 during subsequent or concurrent LPS challenge, respectively. These findings identify IL-10 as a key anti-inflammatory mediator produced by intravenous Ig-treated macrophages and provide insight into a novel mechanism by which intravenous Ig may dampen down inflammatory responses in patients with autoimmune or autoinflammatory diseases.

Insights into IL-23 biology: From structure to function

Interleukin (IL-)23 is a central cytokine controlling TH17 development. Overshooting IL-23 signaling contribute to autoimmune diseases. Moreover, GWAS studies have identified several SNPs within the IL-23 receptor, which are associated with autoimmune diseases. IL-23 is a member of the IL-12-type cytokine family and consists of IL-23p19 and p40. Within the IL-12 family, IL-12 and IL-23 share the p40 cytokine subunit and the IL-12Rβ1 as one chain of the receptor complex. For signaling, IL-23 triggers heterodimerization of IL-12Rβ1 and the IL-23R. Subsequently, signal transduction pathways including JAK/STAT, MAPK and PI3K are activated. Most studies have investigated the biological relevance of IL-23 in the development of TH17 cells and autoimmunity, whereas less is known about the molecular context of IL-23 biology. Therefore, we focused on IL-23 receptor complex assembly, signal transduction and functional relevance of IL-23R SNPs in the context of IL-23-inhibitory principles.

Prophylactic and therapeutic treatment with a synthetic analogue of a parasitic worm product prevents experimental arthritis and inhibits IL-1β production via NRF2-mediated counter-regulation of the inflammasome

Rheumatoid arthritis (RA) remains a debilitating autoimmune condition as many patients are refractory to existing conventional and biologic therapies, and hence successful development of novel treatments remains a critical requirement. Towards this, we now describe a synthetic drug-like small molecule analogue, SMA-12b, of an immunomodulatory parasitic worm product, ES-62, which acts both prophylactically and therapeutically against collagen-induced arthritis (CIA) in mice. Mechanistic analysis revealed that SMA-12b modifies the expression of a number of inflammatory response genes, particularly those associated with the inflammasome in mouse bone marrow-derived macrophages and indeed IL-1β was the most down-regulated gene. Consistent with this, IL-1β was significantly reduced in the joints of mice with CIA treated with SMA-12b. SMA-12b also increased the expression of a number of genes associated with anti-oxidant responses that are controlled by the transcription factor NRF2 and critically, was unable to inhibit expression of IL-1β by macrophages derived from the bone marrow of NRF2(-/-) mice. Collectively, these data suggest that SMA-12b could provide the basis of an entirely novel approach to fulfilling the urgent need for new treatments for RA.

The serum IL-23 level predicts the response to pegylated interferon therapy in patients with chronic hepatitis B

BACKGROUND & AIMS

This study investigated the possible use of interleukin (IL)-23 and IL-17 serum levels as indicators for anti-hepatitis B virus (HBV) therapy.

METHODS

A total of 127 patients with chronic hepatitis B (CHB) who received pegylated interferon (PegIFN) therapy, 20 chronic asymptomatic HBV carriers (AsCs) and 32 healthy controls were recruited. The serum levels of IL-23 and IL-17 were detected by ELISA. The predictive value of baseline and early on-treatment changes in the levels of IL-23 and IL-17 for therapeutic response were evaluated by receiver operating characteristic analysis. Multivariate logistic regression models were generated to identify independent factors that affect the clearance of hepatitis B e antigen (HBeAg) and the decline in hepatitis B surface antigen (HBsAg).

RESULTS

The baseline serum levels of IL-23 and IL-17 were higher in patients with CHB than in normal controls and in AsCs. High levels of pre-treatment IL-23 and IL-17 and more significant on-treatment reductions in IL-23 and IL-17 levels were observed in patients with CHB who achieved HBeAg clearance or a decline in HBsAg >1 log10  IU/ml compared with patients who were persistently HBeAg-positive or who experienced a decline in HBsAg <1 log10  IU/ml. The predictive cut-off value of IL-23 for HBeAg clearance was 135 pg/ml, and the specificity and sensitivity were 71.4% and 70% respectively. A high pre-treatment level of IL-23 was an independent factor for the prediction of the therapeutic response in patients with HBeAg-positive CHB. Early on-treatment changes of IL-23 and IL-17 showed no predictive value.

CONCLUSIONS

A high pre-treatment serum IL-23 level predicts the therapeutic response in HBeAg-positive CHB patients during PegIFN therapy.

Identification and expression analysis of two interleukin-23α (p19) isoforms, in rainbow trout Oncorhynchus mykiss and Atlantic salmon Salmo salar

Interleukin (IL)-23 is a heterodimeric IL-12 family cytokine composed of a p19 α-chain, linked to a p40 β-chain that is shared with IL-12. IL-23 is distinguished functionally from IL-12 by its ability to induce the production of IL-17, and differentiation of Th17 cells in mammals. Three isoforms of p40 (p40a, p40b and p40c) have been found in some 3R teleosts. Salmonids also possess three p40 isoforms (p40b1, p40b2 and p40c) although p40a is missing, and two copies (paralogues) of p40b are present that have presumably been retained following the 4R duplication in this fish lineage. Teleost p19 has been discovered recently in zebrafish, but to date there is limited information on expression and modulation of this molecule. In this report we have cloned two p19 paralogues (p19a and p19b) in salmonids, suggesting that a salmonid can possess six potential IL-23 isoforms. Whilst Atlantic salmon has two active p19 genes, the rainbow trout p19b gene may have been pseudogenized. The salmonid p19 translations share moderate identities (22.8-29.9%) to zebrafish and mammalian p19 molecules, but their identity was supported by structural features, a conserved 4 exon/3 intron gene organisation, and phylogenetic tree analysis. The active salmonid p19 genes are highly expressed in blood and gonad. Bacterial (Yersinia ruckeri) and viral infection in rainbow trout induces the expression of p19a, suggesting pathogen-specific induction of IL-23 isoforms. Trout p19a expression was also induced by PAMPs (poly IC and peptidoglycan) and the proinflammatory cytokine IL-1β in primary head kidney macrophages. These data may indicate diverse functional roles of trout IL-23 isoforms in regulating the immune response in fish.

Increased interleukin-23/17 axis and C-reactive protein are associated with severity of acute pancreatitis in patients

OBJECTIVE

The interleukin (IL)-23/IL-17 axis plays an important role in various inflammatory conditions but its function in acute pancreatitis (AP) is not well understood. The present study investigated the relationship between serum levels of IL-23, IL-17, and C-reactive protein (CRP) in patients and the severity of AP.

METHODS

Eighty-five patients with AP were categorized into mild group, moderately severe group, and severe group according to the revised Atlanta classification, 2012. Serum levels of IL-23 and IL-17 were measured by enzyme-linked immunosorbent assay in patients 48 hours after admission. The CRP levels of patients were also measured on admission and 48 hours after admission.

RESULTS

The serum levels of CRP of patients on admission and 48 hours after admission and levels of IL-23 and IL-17 of patients 48 hours after admission increased alone with the severity of AP, respectively (P < 0.01). The serum levels of IL-23 and IL-17 in the patients were correlated with CRP levels (r = 0.234, r = 0.552, P < 0.001, respectively).

CONCLUSIONS

The serum levels of IL-17, IL-23, and CRP are correlated with the severity of AP and represent valuable prognostic factors in the assessment of disease severity of patients with AP.

Hydrogen/deuterium exchange mass spectrometry applied to IL-23 interaction characteristics: potential impact for therapeutics

IL-23 is an important therapeutic target for the treatment of inflammatory diseases. Adnectins are targeted protein therapeutics that are derived from domain III of human fibronectin and have a similar protein scaffold to antibodies. Adnectin 2 was found to bind to IL-23 and compete with the IL-23/IL-23R interaction, posing a potential protein therapeutic. Hydrogen/deuterium exchange mass spectrometry and computational methods were applied to probe the binding interactions between IL-23 and Adnectin 2 and to determine the correlation between the two orthogonal methods. This review summarizes the current structural knowledge about IL-23 and focuses on the applicability of hydrogen/deuterium exchange mass spectrometry to investigate the higher order structure of proteins, which plays an important role in the discovery of new and improved biotherapeutics.

A novel biological target for the treatment of psoriatic arthritis

Evaluation of: Kavanaugh A, Ritchlin C, Rahman P et al.; on behalf of the PSUMMIT-1 and -2 Study Groups. Ustekinumab, an anti-IL-12/23 p40 monoclonal antibody, inhibits radiographic progression in patients with active psoriatic arthritis: results of an integrated analysis of radiographic data from the Phase 3, multicentre, randomised, double-blind, placebo-controlled PSUMMIT-1 and PSUMMIT-2 trials. Ann. Rheum. Dis. 73(6), 1000-1006 (2014). The IL-23/IL-17 axis plays a major role in the immunopathogenesis of psoriatic arthritis (PsA), inducing the production of proinflammatory cytokines (e.g., IL-1, TNF-α, IL-6 and IL8), osteoclastogenesis and cartilage degradation. This pathway represents a novel target in the treatment of PsA. Ustekinumab is a human monoclonal antibody that prevents the human IL-12/IL-23 p40 subunit from binding to the IL12Rβ1 receptor chain. The current paper sustains that clinical efficacy of ustekinumab is associated with inhibition of radiological progression in active PsA.

Functional polymorphisms in interleukin-23 receptor and susceptibility to coronary artery disease

As a key element in the T-helper 17 (Th17) cell-mediated inflammatory process, interleukin-23 receptor (IL-23R) may play a crucial role in the pathogenesis of atherosclerosis. Single nucleotide polymorphisms (SNPs) in IL-23R have been studied in several diseases. However, its association with coronary artery disease (CAD) remains unclear. This study examined whether genetic polymorphisms in IL-23R were associated with susceptibility to CAD. Two IL-23R SNPs, rs1884444 and rs6682925, were genotyped in 462 CAD patients and 486 healthy controls. Data showed that percentages of rs6682925TC and CC genotypes were significantly higher in patients than in controls (odds ratio [OR]=1.23, 95% confidence interval [CI]: 1.04-1.79, p=0.022; OR=2.35, 95% CI: 1.52-3.43, p<0.001, respectively). Frequency of the rs1884444 polymorphism did not reveal any significant differences between patients and healthy donors. Further analyses demonstrated a significantly increased number of rs6682925CC genotype in patients with hypertension. Moreover, we investigated the effect of IL-23R polymorphisms on gene expression by assessing mRNA level of IL-23R in peripheral blood mononucleated cells (PBMCs). Results showed that subjects carrying rs6682925TC and CC genotypes had significantly increased mRNA level of IL-23R in PBMCs than those with TT genotype. These data suggest that IL-23R rs6682925T/C polymorphism may act as a risk factor of CAD.

Cytokine-modulating strategies and newer cytokine targets for arthritis therapy

Cytokines are the key mediators of inflammation in the course of autoimmune arthritis and other immune-mediated diseases. Uncontrolled production of the pro-inflammatory cytokines such as interferon-γ (IFN-γ), tumor necrosis factor α (TNFα), interleukin-6 (IL-6), and IL-17 can promote autoimmune pathology, whereas anti-inflammatory cytokines including IL-4, IL-10, and IL-27 can help control inflammation and tissue damage. The pro-inflammatory cytokines are the prime targets of the strategies to control rheumatoid arthritis (RA). For example, the neutralization of TNFα, either by engineered anti-cytokine antibodies or by soluble cytokine receptors as decoys, has proven successful in the treatment of RA. The activity of pro-inflammatory cytokines can also be downregulated either by using specific siRNA to inhibit the expression of a particular cytokine or by using small molecule inhibitors of cytokine signaling. Furthermore, the use of anti-inflammatory cytokines or cytokine antagonists delivered via gene therapy has proven to be an effective approach to regulate autoimmunity. Unexpectedly, under certain conditions, TNFα, IFN-γ, and few other cytokines can display anti-inflammatory activities. Increasing awareness of this phenomenon might help develop appropriate regimens to harness or avoid this effect. Furthermore, the relatively newer cytokines such as IL-32, IL-34 and IL-35 are being investigated for their potential role in the pathogenesis and treatment of arthritis.

Acrodermatitis continua of Hallopeau treated successfully with ustekinumab and acitretin after failure of tumour necrosis factor blockade and anakinra

Acrodermatitis continua of Hallopeau (ACH) is a rare form of chronic acral pustular eruption. Considered to be a variant of pustular psoriasis, it is a refractory condition that may not respond to conventional treatments. We report herein the case of a 53-year-old patient whose ACH was refractory to all conventional systemic treatment modalities and to anti-tumour necrosis factor. Because he had increased plasma levels of interleukin (IL)-1β, he received anakinra for 7 weeks, without further improvement however. Achievement of complete response was obtained with ustekinumab 90 mg s.c. every 12 weeks combined with acitretin; the plasma level of IL-1β concomitantly returned to normal. This case report is associated with a review on recent data on ACH treatment with biological agents, including anakinra and ustekinumab.

Ustekinumab improves psoriasis without suppressing tumor antigen-specific cytotoxic T lymphocytes

BACKGROUND

Ustekinumab is currently used for the treatment of psoriasis with remarkable efficiency. However, worries about the development of malignancies in ustekinumab-treated patients have not been completely resolved because of the major role of IL-12 and IL-23 in tumor immunity. In the present study, we tried to elucidate the effects of ustekinumab on antigen-specific tumor immunity.

METHODS

After approval by the institutional ethical committee, a 56-year-old male volunteer with psoriasis was administered with 20 doses of WT1 peptide. WT1-specific cytotoxic T lymphocytes (CTLs) were evaluated by WT1 tetramer assay after mixed lymphocyte peptide culture.

RESULTS

WT1 tetramer+ T cells with cytotoxic ability appeared in the blood after peptide administration and the frequency of WT1 tetramer+ T cells increased to more than 15 in 10(6) CD8+ T cells. Thirty months after stopping WT1 administration, the patient commenced treatment with ustekinumab for psoriasis at weeks 0 and 4, and every 12 weeks thereafter. Psoriasis plaques were almost cleared up and the response to ustekinumab has so far lasted for 30 months. The frequency of WT1 tetramer+ T cells has not changed since the initiation of ustekinumab treatment. The effects of ustekinumab on the antigen-presenting and CTL-inducing abilities of dendritic cells were explored in vitro, revealing limited effects on both immune functions.

CONCLUSIONS

These in vivo/vitro findings imply that ustekinumab improves psoriasis without suppressing tumor antigen-specific CTLs and support the data of recent clinical trials showing no increased incidence of malignancies with ustekinumab treatment.

Therapeutic effect of aripiprazole in chronic schizophrenia is accompanied by anti-inflammatory activity

BACKGROUND

Weight gain and metabolic abnormalities occur in chronic schizophrenia patients treated with atypical antipsychotics. The purpose of the study was to evaluate changes in serum levels of C-reactive protein (CRP), insulin and cytokines (IL-6, TNF-α, IL-1β, IFN-γ, sTNF-R1, IL-12, IL-23, IL-1Ra, TGF-β1, IL-4, and IL-10) after switching to aripiprazole.

METHODS

Cytokine, hsCRP and insulin measurements were performed in patients (n=17) on day 0 and day 28 of the study using standard ELISA assays. The psychopathological status was assessed using PANSS. WC and BMI were measured and calculated, respectively.

RESULTS

We observed high clinical efficacy in aripiprazole linked to a 2.7% weight loss. There were statistically significant reductions in PANSS scores and body parameters (p<0.001). After 28 days we detected a significant reduction in hsCRP (p<0.001), insulin (p<0.001), IL-1β, IL-6, TNF-α, sTNF-R1, IL-12, IL-23, IL-1Ra, TGF-β1, IL-4 (p<0.001), IFN-γ (p<0.05) and a significant elevation of IL-10 (p<0.001). There was a significant negative correlation between IL-10 levels and PANSS positive, negative and total scores after the study (p=0.022, p=0.003, p=0.008, respectively).

CONCLUSIONS

Aripiprazole limits inflammatory processes by enhancing anti-inflammatory signaling. Aripiprazole also reduces the risk of metabolic abnormalities.

Suppression of human and mouse Th17 differentiation and autoimmunity by an endogenous Interleukin 23 receptor cytokine-binding homology region

T-helper 17 (Th17) cells, a recently identified CD4+ T subset with a unique characteristic to produce Interleukin-17 (IL-17), are critical for the development of autoimmune diseases such as multiple sclerosis, in which IL-23 plays an important role in the differentiation of Th17 cells through IL-23/IL-23-receptor/STAT3 pathway. Previously, soluble recombinant human IL-23 receptor cytokine-binding homology region (hIL23R-CHR) was constructed in our laboratory to neutralize IL-23 and inhibit murine Th17 development in vitro. Herein we present that hIL23R-CHR could inhibit both differentiation and function of human/murine Th17 cells. The present in vivo study further demonstrated that hIL23R-CHR inhibited murine Th17 cell development by down regulating IL-17 gene expression and protected mice against the development of experimental autoimmune encephalomyelitis (EAE) through suppression of CNS inflammation and pro-inflammatory cytokine production. In addition to the in vitro inhibition of human Th17 cells in a dose-dependent manner, the antagonizing effect of hIL23R-CHR was confirmed by reduced levels of IL-23 in both blood and brain of EAE mice and STAT3 phosphorylation in vivo. Taken together, our data demonstrated that hIL23R-CHR could be an effective and specific immunosuppressive molecule for the treatment of Th17-related autoimmune diseases.

Interleukins and interleukin receptors in rheumatoid arthritis: Research, diagnostics and clinical implications

Rheumatoid arthritis (RA) is an autoimmune disease, resulting in a chronic, systemic inflammatory disorder. It may affect many tissues and organs, but it primarily affects the flexible joints. In clinical practice patient care generates many questions about diagnosis, prognosis, and treatment. It is challenging for health care specialists to keep up to date with the medical literature. This review summarizes the pathogenesis, the polymorphisms of interleukin and interleukin genes and the standard available and possible future immunologic targets for RA treatment. The identification of disease-associated interleukin and interleukin receptor genes can provide precious insight into the genetic variations prior to disease onset in order to identify the pathways important for RA pathogenesis. The knowledge of the complex genetic background may prove useful for developing novel therapies and making personalized medicine based on the individual’s genetics.

Rheumatoid arthritis pathophysiology: update on emerging cytokine and cytokine-associated cell targets

Biologic therapies that target pathogenic cytokines such as TNF, IL-1β or IL-6 have greatly improved the treatment of RA. Unfortunately, not all RA patients respond to current biologic therapies and responses are not always maintained, suggesting that there are alternative drivers of RA pathogenesis that might serve as promising therapeutic targets. Discovery of the new Th17 subset of Th cells, and their role in autoimmune disease development, has implicated the proinflammatory IL-12 and IL-17 families of cytokines in RA disease pathogenesis. Members of these cytokine families are elevated in the blood and joints of RA patients and have been shown to remain elevated in patients who do not respond to current biologics. In addition, these cytokines have been shown to play roles in joint destruction and erosion. A new subclass of biologics that target the IL-12 and/or IL-17 signalling pathways are under development. Here we review evidence for a role of Th17 cells as well as IL-12 and IL-17 cytokines in RA pathogenesis as the rationale for a subsequent discussion of the ongoing and completed clinical trials of newly emerging biologic therapies directed at IL-12 or IL-17 pathway inhibition.

Genetic update on inflammatory factors in ulcerative colitis: Review of the current literature

Ulcerative colitis (UC) is one of the main types of inflammatory bowel disease, which is caused by dysregulated immune responses in genetically predisposed individuals. Several genetic factors, including interleukin and interleukin receptor gene polymorphisms and other inflammation-related genes play central role in mediating and modulating the inflammation in the human body, thereby these can be the main cause of development of the disease. It is clear these data are very important for understanding the base of the disease, especially in terms of clinical utility and validity, but summarized literature is exiguous for challenge health specialist that can used in the clinical practice nowadays. This review summarizes the current literature on inflammation-related genetic polymorphisms which are associated with UC. We performed an electronic search of Pubmed Database among publications of the last 10 years, using the following medical subject heading terms: UC, ulcerative colitis, inflammation, genes, polymorphisms, and susceptibility.

Amygdalin analogues inhibit IFN-γ signalling and reduce the inflammatory response in human epidermal keratinocytes

Peptide T (PT), an octapeptide fragment located in the V2 region of the HIV-1 gp120-coating protein, appears to be beneficial in the treatment of psoriasis. Our previous investigations suggest that keratinocytes play a key role in conditioning the therapeutic effects of PT in psoriasis. The aim of this study was to explore the effects of PT and the peptidomimetic natural products, Dhurrin and Prunasin, on the expression of the IL-6, IL-8, IL-23, HSP70 and ICAM-1 on IFN-γ and TNF-α-NHEK activated cells. Moreover, we analysed the interference of PT and its analogues through STAT-3 activation. Our results show that the analogues tested exhibit the beneficial biological effects of PT, suggesting the primary role of keratinocytes upon which PT and the peptidomimetics act directly, by reducing proinflammatory responses. Its reduction appears to be important for therapeutic approach in psoriasis pathogenesis.

The use of cytokine signature patterns: separating drug naïve, interferon and natalizumab-treated multiple sclerosis patients

Multiple sclerosis (MS) is an inflammatory illness characterized by demyelination and axonal neurodegeneration. Here, we used serum samples from MS patients to demonstrate if "cytokine signature" patterns can separate different patient groups better than using single cytokines. In this case, we used cytokine profiling to demonstrate if "cytokine signature" patterns can separate MS patients treated with interferon or natalizumab from drug naïve patients. Serum levels of eight individual cytokines (TNFα, IFNγ, S100B, IL-1β, IL-6, IL-8, IL-17 and IL-23) in MS patients treated with interferons (n = 11) and natalizumab (n = 14) were measured and, in general, showed reduced levels compared to drug naïve MS patients (n = 12). More evident changes were seen when analyzing "cytokine signatures" (i.e. summed value of all eight cytokines), which showed that patients treated with natalizumab and interferons showed significantly reduced cytokine signature levels than drug naïve MS patients. Moreover, patients treated with natalizumab were separated from drug naïve patients by almost 100% fidelity and that patients treated with natalizumab also had reduced levels of pro-inflammatory cytokines compared to patients treated with interferon. Overall, this study provides an example showing that the use of "cytokine signatures" may provide benefits over the analysis of single cytokines for the development of potential biomarkers.

Sulforaphane protects from T cell-mediated autoimmune disease by inhibition of IL-23 and IL-12 in dendritic cells

Sulforaphane (SFN), an isothiocyanate, is part of an important group of naturally occurring small molecules with anti-inflammatory properties. The published reports are best conceivable with an inhibition of T cell function, but the mode of action remains unknown. We therefore analyzed the effect of SFN on T cell-mediated autoimmune disease. Feeding mice with SFN protected from severe experimental autoimmune encephalomyelitis. Disease amelioration was associated with reduced IL-17 and IFN-γ expression in draining lymph nodes. In vitro, SFN treatment of T cells did not directly alter T cell cytokine secretion. In contrast, SFN treatment of dendritic cells (DCs) inhibited TLR4-induced IL-12 and IL-23 production, and severely suppressed Th1 and Th17 development of T cells primed by SFN-treated DCs. SFN regulated the activity of the TLR4-induced transcription factor NF-κB, without affecting the degradation of its inhibitor IκB-α. Instead, SFN treatment of DCs resulted in strong expression of the stress response protein heme oxygenase-1 (HO-1), which interacts with and thereby inhibits NF-κB p65. Consistent with these findings, HO-1 bound to p65 and subsequently inhibited the p65 activity at the IL23a and IL12b promoters. Importantly, SFN suppressed Il23a and Il12b expression in vivo and silenced Th17/Th1 responses within the CNS. Thus, our data show that SFN improves Th17/Th1-mediated autoimmune disease by inducing HO-1 and inhibiting NF-κB p65-regulated IL-23 and IL-12 expression.

Role of IL-23 in the pathogenesis of psoriasis: a novel potential therapeutic target?

INTRODUCTION

Psoriasis is a chronic inflammatory skin disorder determined by the activation of several immune cells and resident tissue cells. Various cytokines mediate inflammatory signals, including IL-23, which is an important factor involved in the differentiation of T helper (Th17) cells.

AREAS COVERED

Increasing evidence suggests that IL-23 is a central cytokine to the pathogenesis of psoriasis. An overview on both experimental and human data will be reported in order to support the hypothesis of a key pathogenic role of IL-23/Th17 axis.

EXPERT OPINION

Targeting IL-23 might be a more selective, valid and effective therapeutic approach, which, potentially, may show important advantages in terms of long-term efficacy and safety in the treatment of psoriasis.

Profile of ustekinumab and its potential in the treatment of active psoriatic arthritis

Psoriatic arthritis (PsA) is a chronic inflammatory arthritis and considered to be a less severe condition than rheumatoid arthritis. PsA patients have been treated for a long time with a number of different agents, from non-steroidal anti-inflammatory drugs to one or more disease-modifying antirheumatic drugs. In the last decade, recognition of the central role of tumor necrosis factor-alpha (TNFα) in the immunopathogenesis of many rheumatic diseases, including PsA, has led to the development of TNFα blockers. In PsA, these agents are uniquely efficacious in the treatment of different patterns of the disease, as well as slowing progression of erosive damage in the peripheral joints. However, a significant number of patients withdraw from therapy because of failure or poor tolerability. Among the novel therapeutic targets, interleukin (IL)-23/IL-12 has been investigated for the treatment of chronic inflammatory disease. In particular, ustekinumab is a human monoclonal antibody that prevents human IL-12 and IL-23 from binding to the IL-12Rβ1 receptor chain of IL-12 (IL-12Rβ1/β2) and IL-23 (IL-12Rβ1/23R) receptor complexes on the surface of natural killer cells and T-cells. Ustekinumab has been approved only for treatment of chronic plaque psoriasis, but also represents an interesting agent for treatment of PsA.

Involvement of IL-23 in enteropathic arthritis patients with inflammatory bowel disease: preliminary results

The role of interleukin (IL)-23 in the pathogenesis of inflammatory bowel disease (IBD) remains unclear. The aim of this work was to study the serum level of IL-23 in IBD with and without arthritis and determine its relation to the subsets and clinical features of the disease. Thirty-seven patients with IBD including 11 with arthritis were included in the study with a mean age of 30.86 ± 4.66 years. Twenty healthy subjects served as control. Seronegative spondyloarthropathy was present in 11 (29.73 %) of the IBD patients; Crohn's disease (CD) was present in 23 and 14 had ulcerative colitis (UC). Serum level of IL-23 was measured in all patients and control by ELISA. IL-23 was significantly higher in IBD patients (46.24 ± 27.19 pg/ml) compared to control (24.1 ± 2.31 pg/ml) (p < 0.0001) being higher in CD patients (52.57 ± 32.78 pg/ml) compared to those with UC (35.86 ± 6.41 pg/ml) (p = 0.026). Furthermore, it was significantly higher in those with peripheral and/or axial arthritis (67.73 ± 40.85 pg/ml) compared to patients without (37.15 ± 10.37 pg/ml) (p = 0.03). There was a tendency to a higher level in males (49.15 ± 30.97 pg/ml) compared to females (38.4 ± 9.54 pg/ml). Serum IL-23 is increased in IBD especially those with CD associated with arthritis and sacroiliitis. The IL-23 could be added to the biomarkers of development of arthritis in IBD patients. These results also confirm the findings of previous studies on the critical role played by IL-23 in the pathogenesis of IBD making it an important new therapeutic target for these patients.

Specific targeting of interleukin-23p19 as effective treatment for psoriasis

Interleukin (IL)-23 is a heterodimeric cytokine composed of a distinct p19 subunit and a p40 subunit, which it shares with IL-12. The dermatology and rheumatology communities have long surmised that anti-IL-12/23p40 antibodies suppress autoinflammatory disease owing to their effect on IL-12. The aim of this review is to bring to light new data from murine and human studies demonstrating that in fact IL-23 and its resulting Th17 pathway mediate the inflammatory cascade that induces psoriatic plaque formation. Evidence derives from lesional immunohistochemical analyses, genetic studies, and research in other autoimmune diseases. Although current IL-12/23p40 inhibitors have shown good efficacy and safety, data regarding the functional role of IL-12 in immune defense suggest that preserving this cytokine would be beneficial. To date, evidence from mouse models and preliminary data in human beings show that specifically targeting IL-23p19 may be a safer but equally efficacious treatment option.

The cytokine networks of adaptive immunity in fish

Cytokines, produced at the site of entry of a pathogen, drive inflammatory signals that regulate the capacity of resident and newly arrived phagocytes to destroy the invading pathogen. They also regulate antigen presenting cells (APCs), and their migration to lymph nodes to initiate the adaptive immune response. When naive CD4+ T cells recognize a foreign antigen-derived peptide presented in the context of major histocompatibility complex class II on APCs, they undergo massive proliferation and differentiation into at least four different T-helper (Th) cell subsets (Th1, Th2, Th17, and induced T-regulatory (iTreg) cells in mammals. Each cell subset expresses a unique set of signature cytokines. The profile and magnitude of cytokines produced in response to invasion of a foreign organism or to other danger signals by activated CD4+ T cells themselves, and/or other cell types during the course of differentiation, define to a large extent whether subsequent immune responses will have beneficial or detrimental effects to the host. The major players of the cytokine network of adaptive immunity in fish are described in this review with a focus on the salmonid cytokine network. We highlight the molecular, and increasing cellular, evidence for the existence of T-helper cells in fish. Whether these cells will match exactly to the mammalian paradigm remains to be seen, but the early evidence suggests that there will be many similarities to known subsets. Alternative or additional Th populations may also exist in fish, perhaps influenced by the types of pathogen encountered by a particular species and/or fish group. These Th cells are crucial for eliciting disease resistance post-vaccination, and hopefully will help resolve some of the difficulties in producing efficacious vaccines to certain fish diseases.

Immunoexpression of interleukin-22 and interleukin-23 in oral and cutaneous lichen planus lesions: a preliminary study

Interleukin- (IL-) 22 is the signature cytokine of T-helper (Th) 22 cells, and IL-23 is required for IL-22 production. The objective of this study was to examine the immunoexpression of IL-22 and IL-23 in archival paraffin-embedded biopsy specimens from oral LP (n = 42) and cutaneous LP (n = 38) against normal control tissues. The results showed that the percentage of cells expressing IL-22 and IL-23 in LP were significantly higher in LP compared to controls, respectively (both P < 0.001). The correlation between IL-22 and IL-23 expression was significant (P < 0.05). Moreover, the percentage of cells expressing IL-22 and IL-23 in oral LP were significantly higher than cutaneous LP (P < 0.05). Collectively, our findings demonstrated that the increased expression of IL-22 and IL-23 in LP lesions could play roles in the pathogenesis of LP. Moreover, oral LP expressing IL-22 and IL-23 was higher than cutaneous LP, probably due to Th22 cells as an important component of oral mucosal host defense against oral microbiota and tissue antigens. This may be associated with the difference in clinical behaviour of the two variants of the disease.

Designing anti-inflammatory drugs from parasitic worms: a synthetic small molecule analogue of the Acanthocheilonema viteae product ES-62 prevents development of collagen-induced arthritis

In spite of increasing evidence that parasitic worms may protect humans from developing allergic and autoimmune diseases and the continuing identification of defined helminth-derived immunomodulatory molecules, to date no new anti-inflammatory drugs have been developed from these organisms. We have approached this matter in a novel manner by synthesizing a library of drug-like small molecules based upon phosphorylcholine, the active moiety of the anti-inflammatory Acanthocheilonema viteae product, ES-62, which as an immunogenic protein is unsuitable for use as a drug. Following preliminary in vitro screening for inhibitory effects on relevant macrophage cytokine responses, a sulfone-containing phosphorylcholine analogue (11a) was selected for testing in an in vivo model of inflammation, collagen-induced arthritis (CIA). Testing revealed that 11a was as effective as ES-62 in protecting DBA/1 mice from developing CIA and mirrored its mechanism of action in downregulating the TLR/IL-1R transducer, MyD88. 11a is thus a novel prototype for anti-inflammatory drug development.

Plasma Levels of IL-23 and IL-17 before and after Antidepressant Treatment in Patients with Major Depressive Disorder

OBJECTIVE

Cytokines are believed to have a role in the pathophysiology of major depression. The alteration in levels of pro-inflammatory cytokines [interleukin 1β (IL-1β), IL-2, IL-6, IL-12, interferon γ, and tumor necrosis factor α] in major depression supports the cytokine hypothesis of this illness. IL-23 and IL-17 are also pro-inflammatory cytokines, but few studies have focused on their role in major depression. This study investigated the potential role of the IL-23 and IL-17 axis in major depression.

METHODS

Plasma IL-23 and IL-17 levels were measured in 26 major depressive disorder (MDD) patients before and after 6-week treatment with antidepressants; these levels were measured in 28 age- and sex-matched normal controls. Depression severity was assessed using the Hamilton Depression Rating Scale (HDRS). IL-23 and IL-17 plasma levels were estimated using quantitative enzyme-linked immunosorbent assay.

RESULTS

Pre-treatment plasma levels of IL-23 and IL-17 in MDD patients were not significantly different from those of normal controls. In MDD patients, IL-23 and IL-17 levels after 6 weeks of antidepressant treatment were not different from the baseline levels. There was no significant correlation between changes in the cytokine levels and changes in the HDRS scores representing the severity of depression.

CONCLUSION

The present study does not support a potential involvement of IL-23 and IL-17 axis in major depression. Replication and extension using a larger sample are required.

Antimicrobial effect of natural polyphenols with or without antibiotics on Chlamydia pneumoniae infection in vitro

Chlamydia pneumoniae is a human pathogen that causes multiple diseases worldwide. Despite appropriate therapy with antichlamydial antibiotics, chronic exacerbated diseases often occur and lead to serious sequelae. The use of the macrolide clarithromycin and the fluoroquinolone ofloxacin has improved the treatment of chlamydial infection, but therapy failure is still a major problem. In this work, we studied the pretreatment with natural polyphenols and subsequent treatment with clarithromycin or ofloxacin. The phenolic compounds resveratrol and quercetin improved the antichlamydial effect of clarithromycin and ofloxacin. In particular, resveratrol at 40 μM and quercetin at 20 μM exhibited significant growth inhibition on C. pneumoniae in presence of clarithromycin or ofloxacin compared to controls. In addition, we demonstrated that both resveratrol and quercetin decreased IL-17 and IL-23 production in a time-dependent manner in C. pneumoniae-infected cells. The results showed a particularly strong inhibition of the IL-23 levels released with combined treatment of resveratrol or quercetin and ofloxacin or clarithromycin, suggesting that the combined treatment may afford a synergistic effect in controlling Chlamydia infections.

Inflammatory mediators in the pathogenesis of periodontitis

Periodontitis is a chronic inflammatory condition of the periodontium involving interactions between bacterial products, numerous cell populations and inflammatory mediators. It is generally accepted that periodontitis is initiated by complex and diverse microbial biofilms which form on the teeth, i.e. dental plaque. Substances released from this biofilm such as lipopolysaccharides, antigens and other virulence factors, gain access to the gingival tissue and initiate an inflammatory and immune response, leading to the activation of host defence cells. As a result of cellular activation, inflammatory mediators, including cytokines, chemokines, arachidonic acid metabolites and proteolytic enzymes collectively contribute to tissue destruction and bone resorption. This review summarises recent studies on the pathogenesis of periodontitis, with the main focus on inflammatory mediators and their role in periodontal disease.

Association study in Romanians confirms IL23A gene haplotype block rs2066808/rs11171806 as conferring risk to psoriatic arthritis

BACKGROUND

The cytokines IL12 and IL23 have been recently implicated in the pathogenesis of psoriatic arthritis (PsA). In this study we investigated the genetic variations in the genes coding for IL12, IL23 and IL23 receptor as a plausible source of susceptibility and modification of clinical symptoms of PsA in Romanian population.

METHODS

Twenty five SNPs mapping to IL12A, IL12B, IL23A, IL23R and IL12RB1 genes were genotyped in 94 PsA patients and 161 healthy controls of Romanian ethnicity using the Sequenom genotyping platform.

RESULTS

The exonic SNP rs11171806 from IL23A gene was significantly underrepresented in patients versus controls (p=0.03, OR 0.391) and the carriers of rs11171806/rs2066808 AC haplotype had decreased risk for PsA (p=0.03). The two SNPs of the highly conserved gene IL23A are in complete LD in our population. Genetic variants of IL12B gene were associated with polyarticular subtype of PsA. No associations were found between SNPs from IL12A, IL23R and IL12RB1 genes and susceptibility to PsA and its phenotypes.

CONCLUSION

We confirm the previously described association of rs2066808 variant with psoriasis and PsA and we show evidence of an extended genomic region inside IL23A gene as carrier of true disease susceptibility factors. These data suggest a role for IL23 in the PsA pathogenesis in Romanians.

Concurrent treatment of chronic psoriasis and asthma with ustekinumab

A 56-year-old woman with a 40-year history of guttate flares of psoriasis associated with stress and infection as well as chronic asthma was treated with subcutaneous injections of ustekinumab, repeated after 1 month and then every 3 months. Her psoriasis completely resolved, and her capacity for exercise was markedly increased and asthma maintenance medications were no longer needed. Ustekinumab is a human monoclonal antibody that binds the p40 subunit of IL-12 and IL-23 to limit the progression of the Th1 and Th17 inflammatory immune responses that maintain many autoimmune and inflammatory diseases. Th17-related responses drive inflammation during late stages of chronic asthma and can also be blocked by ustekinumab. Blocking the underlying cytokine-mediated inflammatory responses for psoriasis with ustekinumab can also treat other chronic inflammatory diseases.

Successful therapy of visceral leishmaniasis with curdlan involves T-helper 17 cytokines

The aim of this study was to evaluate and characterize the therapeutic potential of curdlan, a naturally occurring β-glucan immunomodulator, against visceral leishmaniasis, a fatal parasitic disease. Curdlan eliminated the liver and spleen parasite burden in a 45-day BALB/c mouse model of visceral leishmaniasis at a dosage of 10 mg/kg/day as determined by Giemsa-stained organ impression smears. Curdlan was associated with production of the disease-resolving T-helper (Th) 1 and Th17-inducing cytokines interleukin (IL)-6, IL-1β, and IL-23, as well as with production of Th17 cytokines IL-17 and IL-22, as determined by enzyme-linked immunosorbent assay (ELISA) and real time polymerase chain reaction (RT-PCR). Reversal of curdlan-mediated protection by anti-IL-17 and anti-IL-23 monoclonal antibodies showed the importance of Th17 cytokines. Significantly decreased production of both IL-17 and IL-22 by mice that received anti-IL-23 antibody suggested the essential role of IL-23 in Th17 differentiation. Although administration of recombinant IL-17 or IL-23 caused significant suppression of the organ parasite burden, with marked generation of interferon γ and nitric oxide (NO), effects were much faster for IL-17. These results documented that although both IL-23 and IL-17 play major roles in the antileishmanial effect of curdlan, the effect of IL-23 may occur indirectly, through the induction of IL-17 production.

Ustekinumab in chronic immune-mediated diseases: a review of long term safety and patient improvement

Ustekinumab is a fully human monoclonal antibody targeting the common p40 subunit shared by interleukin (IL)-12 and IL-23. Ustekinumab prevents the interaction of IL-12 and IL-23 with their cell surface receptors, and thus blocks T helper (Th)-1 IL-12 and Th-17 IL-23 inflammatory pathways. Ustekinumab has been evaluated in the treatment of various chronic immune-mediated diseases including, psoriasis, psoriatic arthritis, Crohn's disease, and multiple sclerosis. It led to a rapid and durable improvement in psoriasis area and severity index in patients with moderate to severe psoriasis. Ustekinumab also improved joint symptoms of psoriatic arthritis. Results in Crohn's disease were more mitigated, albeit with a symptomatic improvement in patients refractory to tumor necrosis factor-α inhibitors. Ustekinumab did not reduce the number of magnetic resonance imaging brain lesions in multiple sclerosis. The most common adverse events to have been observed during clinical trials are mild in intensity, and include respiratory tract infections, nasopharyngitis, headaches, and injection site reactions. A pooled analysis of clinical trial data indicated no specific patterns of infection or malignancy under long-term ustekinumab administration. Ustekinumab is easy to use, has a comfortable therapeutic regimen, improves quality of life in patients, and thus appears to be an attractive biological treatment that is adapted and accepted by patients with moderate to severe psoriasis.

Upregulation of stromal cell-derived factor by IL-17 and IL-18 via a phosphatidylinositol 3-kinase-dependent pathway

Th17 cells that produce interleukin (IL)-17 play a key role in the pathogenesis of autoimmune inflammation. Among the various cytokines that are involved in the IL-17 pathway, members of the IL-1β family, including IL-18, have recently gained attention. In this study, we stimulated synovial fibroblasts with a combination of IL-17 and IL-18 and quantified their stromal cell-derived factor-1 (SDF-1) production by enzyme-linked immunosorbent assay and their transcript levels by reverse transcription-polymerase chain reaction. Both IL-17 and IL-18 significantly increased the level of SDF-1, not only individually but also synergistically (P< 0.05). The synergism was effectively suppressed by anti-IL-17 and -IL-18 antibodies, and a PI3K inhibitor. To the best of our knowledge, this is the first report of PI3K-dependent synergism between IL-18 and IL-17, and this work adds a novel perspective of the role of IL-18 in immune regulation. The individual effects of these two cytokines, and their interactions, suggest an interrelationship between the IL-1 family and IL-17.