Role of IL-33 and its receptor in T cell-mediated autoimmune diseases

The role of IL-19, IL-24, IL-21 and IL-33 in intestinal mucosa of inflammatory bowel disease: A narrative review

Interleukins are potential therapeutic targets that can alter the prognosis and progression of inflammatory bowel disease (IBD). The roles of IL-6, IL-10, IL-17, and IL-23 have been extensively studied, setting the stage for the development of novel treatments for patients with IBD. Other cytokines have been less extensively studied. Members of the IL-20 family, mainly IL-19 and IL-24, are involved in the pathogenesis of IBD, but their exact role remains unclear. Similarly, IL-33, a newly identified cytokine, has been shown to control the Th1 effector response and the action of colonic Tregs in animal models of colitis and patients with IBD. IL-21 is involved in the Th1, Th2, and Th17 responses. Data support a promising future use of these interleukins as biomarkers of severe diseases and as potential therapeutic targets for novel monoclonal antibodies. This review aims to summarize the existing studies involving animal models of colitis and patients with IBD to clarify their role in the intestinal mucosa.

The Role of Selected Interleukins in the Development and Progression of Multiple Sclerosis-A Systematic Review

Multiple sclerosis is a disabling inflammatory disorder of the central nervous system characterized by demyelination and neurodegeneration. Given that multiple sclerosis remains an incurable disease, the management of MS predominantly focuses on reducing relapses and decelerating the progression of both physical and cognitive decline. The continuous autoimmune process modulated by cytokines seems to be a vital contributing factor to the development and relapse of multiple sclerosis. This review sought to summarize the role of selected interleukins in the pathogenesis and advancement of MS. Patients with MS in the active disease phase seem to exhibit an increased serum level of IL-2, IL-4, IL-6, IL-13, IL-17, IL-21, IL-22 and IL-33 compared to healthy controls and patients in remission, while IL-10 appears to have a beneficial impact in preventing the progression of the disease. Despite being usually associated with proinflammatory activity, several studies have additionally recognized a neuroprotective role of IL-13, IL-22 and IL-33. Moreover, selected gene polymorphisms of IL-2R, IL-4, IL-6, IL-13 and IL-22 were identified as a possible risk factor related to MS development. Treatment strategies of multiple sclerosis that either target or utilize these cytokines seem rather promising, but more comprehensive research is necessary to gain a clearer understanding of how these cytokines precisely affect MS development and progression.

Interleukin-33 Expression on Treatment Outcomes and Prognosis in Brazilian Breast Cancer Patients Undergoing Neoadjuvant Chemotherapy

Interleukin-33 (IL-33), a member of the interleukin-1(IL-1) family of cytokines, remains poorly understood in the context of human breast cancer and its impact on treatment outcomes. This study aimed to elucidate IL-33 expression patterns within tumor samples from a cohort of Brazilian female breast cancer patients undergoing neoadjuvant chemotherapy while exploring its correlation with clinicopathological markers. In total, 68 samples were meticulously evaluated, with IL-33 expression quantified through a quantitative polymerase chain reaction. The findings revealed a substantial upregulation of IL-33 expression in breast cancer patient samples, specifically within the Triple-negative and Luminal A and B subtypes, when compared to controls (healthy breast tissues). Notably, the Luminal B subtype displayed a marked elevation in IL-33 expression relative to the Luminal A subtype (p < 0.05). Moreover, a progressive surge in IL-33 expression was discerned among Luminal subtype patients with TNM 4 staging criteria, further underscoring its significance (p < 0.005). Furthermore, chemotherapy-naïve patients of Luminal A and B subtypes exhibited heightened IL-33 expression (p < 0.05). Collectively, our findings propose that chemotherapy could potentially mitigate tumor aggressiveness by suppressing IL-33 expression in breast cancer, thus warranting consideration as a prognostic marker for gauging chemotherapy response and predicting disease progression in Luminal subtype patients. This study not only sheds light on the intricate roles of IL-33 in breast cancer but also offers valuable insights for future IL-33-related research endeavors within this context.

Expression of IL-21 and IL-33 in Intestinal Mucosa of Inflammatory Bowel Disease: An Immunohistochemical Study

Interleukins are considered to be potential therapeutic targets that can alter the prognosis and disease progression of IBD. IL-21 has proven to be involved in effector Th1, Th2 and Th17 responses. Similarly, IL-33, a newly identified cytokine, has been shown to control the Th1 effector response and the action of the colonic Tregs in animal models of colitis and patients with IBD. In this retrospective study, we have studied the expression of these interleukins, using immunohistochemistry, in 121 patients with moderate to severe IBD before and after treatment with biologics. The results were statistically processed using SPSS^TM. Increased IL-21 expression was found in the UC and CD groups versus the controls. The IL-33 expression was found to be increased in the post-treatment UC and CD groups, suggesting a protective role of this interleukin against bowel inflammation. The IL-33 expression post-treatment was reversely correlated with the activity index score in CD patients, suggesting a better response to treatment in patients with higher IL-33 mucosa levels. This is the first immunohistochemical study of the expression of those interleukins in bowel mucosa before and after treatment with biologics. These data support a possibly promising future use of these interleukins as biomarkers of severe disease and response to treatment and as potential therapeutic targets for novel monoclonal antibodies.

The Role of IL-33/ST2 in COPD and Its Future as an Antibody Therapy

COPD is a leading cause of mortality and morbidity worldwide and is associated with a high socioeconomic burden. Current treatment includes the use of inhaled corticosteroids and bronchodilators, which can help to improve symptoms and reduce exacerbations; however, there is no solution for restoring lung function and the emphysema caused by loss of the alveolar tissue. Moreover, exacerbations accelerate progression and challenge even more the management of COPD. Mechanisms of inflammation in COPD have been investigated over the past years, thus opening new avenues to develop novel targeted-directed therapies. Special attention has been paid to IL-33 and its receptor ST2, as they have been found to mediate immune responses and alveolar damage, and their expression is upregulated in COPD patients, which correlates with disease progression. Here we summarize the current knowledge on the IL-33/ST2 pathway and its involvement in COPD, with a special focus on developed antibodies and the ongoing clinical trials using anti-IL-33 and anti-ST2 strategies in COPD patients.

PADI4 and IL-33 gene polymorphisms associated with differential susceptibility to juvenile-onset systemic lupus erythematosus and juvenile idiopathic arthritis in Chinese children

BACKGROUND

Juvenile systemic lupus erythematosus (JSLE) and juvenile idiopathic arthritis (JIA) are two common types of autoimmune diseases in children with unclear pathogenesis. Both peptidyl arginine deiminase type IV (PADI4) and interleukin 33 (IL-33) are the key molecular involved in immune responses in autoimmune diseases. Usually, it may share the same risk genetic alleles for autoimmune diseases.

METHODS

So measurement of PADI4 and IL-33 polymorphisms was conducted with 303 healthy controls, 144 JSLE patients and 160 JIA patients in this study.

RESULTS

It demonstrated that there was a significant association between PADI4 genotypes (rs2240340: CT, CT + CC), IL-33 genotype (rs1929992: TT) and JSLE susceptibility in Southwest China population. While no significant association with the risk of JIA were observed no matter at allelic or genotypic levels.

CONCLUSIONS

Our study reveals the importance of PADI4 and IL-33 polymorphisms with JSLE risk and their roles in the development of the diseases need more further researches.

Quercetin Ameliorates Renal Injury and Pyroptosis in Lupus Nephritis through Inhibiting IL-33/ST2 Pathway In Vitro and In Vivo

Lupus nephritis (LN) is a common and serious symptom in patients with systemic lupus erythematosus (SLE). Tubular interstitial fibrosis is a common underlying mechanism in the development of lupus nephritis to end-stage renal failure (ESRD). Quercetin is widely proven to prevent tissue fibrosis. Therefore, the purpose of this study is to investigate the beneficial effects of quercetin on the inhibition of fibrosis and inflammation pathways in in vitro and in vivo lupus nephritis models. In the current study, MRL/lpr mice as animal models, and HK-2 human renal tubular epithelial cells were stimulated by interleukin-33 (IL-33) to mimic the cellular model of lupus nephritis. Immunohistochemical staining, immunoblotting assay, immunofluorescence staining, and quantitative real-time polymerase chain reaction assay were used. The in vivo results showed that quercetin improved the renal function and inhibited both fibrosis- and inflammation-related markers in MRL/lpr mice animal models. The in vitro results indicated that quercetin ameliorated the accumulation of fibrosis- and inflammation-related proteins in IL-33-induced HK-2 cells and improved renal cell pyroptosis via the IL33/ST2 pathway. Overall, quercetin can improve LN-related renal fibrosis and inflammation, which may offer an effective potential therapeutic strategy for lupus nephritis.

Dendritic cells drive profibrotic inflammation and aberrant T cell polarization in systemic sclerosis

OBJECTIVES

Systemic sclerosis (SSc) is a devastating autoimmune disease characterized by fibrosis and obliterative vasculopathy affecting the skin and visceral organs. While the processes mediating excessive extracellular matrix (EM) deposition and fibroblast proliferation are clear, the exact link between autoimmunity and fibrosis remains elusive. Th17 cells have been proposed as critical drivers of profibrotic inflammation during SSc, but little is known about the immune components supporting their pathogenic role.

METHODS

Dendritic cells (DCs) activate and shape T cell differentiation by producing polarizing cytokines. Hence, we investigated the cytokine responses of monocyte-derived DCs (Mo-DCs) from patients with limited cutaneous SSc (lcSSc), diffuse cutaneous SSc (dcSSc), and healthy controls (HC) after stimulation with toll-like receptor (TLR) agonists. Also, using co-culture assays, we analyzed T cell subpopulations after contact with autologous TLR-activated Mo-DCs.

RESULTS

In general, we observed an increased production of Th17 related cytokines like IL-1β, IL-17F, IL-21, IL-22 by SSc compared with HC Mo-DCs, with variations between lcSSc vs. dcSSc and early- vs. late-stage subgroups. Noticeably, we found a significant increment in IL-33 production by Mo-DCs in all SSc cases regardless of their clinical phenotype. Strikingly, T cells displayed Th2, Th17, and dual Th2/Th17 phenotypes after exposure to autologous TLR-stimulated Mo-DCs from SSc patients but not HC. These changes were pronounced in individuals with early-stage dcSSc and less significant in the late-stage lcSSc subgroup.

CONCLUSIONS

Our findings suggest that functional alterations of DCs subsidize the immune mechanisms favoring the aberrant T cell polarization and profibrotic inflammation behind the clinical SSc heterogeneity.

IL-33/ST2 axis in autoimmune disease

Interleukin-33 (IL-33) is a member of the IL-1 family and plays an ambivalent role in autoimmune diseases. IL-33 signals via the ST2 receptor and drives cytokine production in mast cells, basophils, eosinophils, NK cells, and T lymphocyte cells. The vital role of IL-33 as an active component gives rise to aberrant local and systemic damage which has been demonstrated in numerous inflammatory disorders and immune-mediated pathological conditions including multiple sclerosis (MS), rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), psoriasis, Sjogren's syndrome, inflammatory bowel disease (IBD), etc. IL-33/ST2 axis can up-regulate pro-inflammatory cytokine release in autoimmune disease, however, in some metabolic diseases like diabetes mellitus type 1 IL-33 can be considered an anti-inflammatory cytokine. The purpose of this review is to discuss selected studies on IL-33/ST2 axis in autoimmune diseases and its potential role as a pathogenic or protective cytokine.

Interleukin-33 promotes invasiveness of human ovarian endometriotic stromal cells through the ST2/MAPK/MMP-9 pathway activated by 17β-estradiol

OBJECTIVE

Endometriosis is an estrogen-dependent, benign, and chronic gynecological disorder occurring in women of reproductive age. Although the pathogenesis of endometriosis is poorly understood, implantation theory indicates that viable endometrial cells shed from the endometrium into the pelvic peritoneum or ovaries, possibly through retrograde menstruation, and then reattach, invade, and damage other tissues. Interleukin (IL)-33, a new member of the IL-1 superfamily, is mainly upregulated by stromal cells following proinflammatory stimulation. Matrix metalloproteinases (MMPs) are involved in the degradation and reconstruction of the extracellular matrix. MMP-9 participates in the pathogenesis of endometriosis by promoting the invasion of endometriotic cells. This study investigated the effect of IL-33 on the cell invasion ability of and MMP-9 expression in human stromal cells derived from ovarian endometrioma (hOVEN-SCs).

MATERIALS AND METHODS

We isolated hOVEN-SCs from human ovarian endometrioma. Gene expression was analyzed using the Illumina Human WG-6 v2 Expression BeadChips microarray platform and through reverse transcription-polymerase chain reaction. Cell migration and invasion were examined by performing the transwell chamber assay.

RESULTS

We found that 17β-estradiol could increase the expression of IL-33 and ST2 through the estrogen receptor pathway in hOVEN-SCs. Moreover, IL-33 upregulated MMP-9 expression in and enhanced the invasion ability of hOVEN-SCs through the ST2/MAPK signaling pathway. Our results showed that MMP-9 expression was essential for IL-33-induced cell invasion.

CONCLUSION

Our main finding is that 17β-estradiol could increase IL-33 expression through the estrogen receptor pathway and activate MMP-9 expression in and invasion ability of hOVEN-SCs through the IL-33/ST2/MAPK signaling pathway. The results of this study and further related studies may provide new strategies for the prevention and treatment of endometriosis.

Dysregulated Interleukin -33/ST2 Pathway Perpetuates Chronic Inflammation in Hashimoto’s Thyroiditis

Objective:

Hashimoto’s Thyroiditis (HT) is an autoimmune disease, characterized by chronic inflammation of the thyroid gland with unknown etiologies. Recently, interleukin-33/ST2 (IL- 33/ST2) pathway reveals its participation in the process of several autoimmune diseases. In this study, the role of IL-33/ST2 pathway in the development of HT is investigated.

Methods:

The levels of plasma IL-33, sST2 and the frequency of circulating CD4+ST2L+T cells in 30 HT patients and 20 healthy controls were determined by enzyme-linked immunosorbent assay (ELISA) and flow cytometry respectively. The mRNA expressions of related molecules in IL-33/ST2 pathway in thyroid tissues (12 HT patients and 10 controls) were detected by real-time quantitative PCR (RTqPCR). The protein expressions of IL-33 and ST2 were determined by Western blot and immunohistochemistry staining.

Results:

The mRNA expressions of plasma IL-33 and sST2 were elevated in HT patients, with an increased ratio of IL-33/sST2. The number of CD4+ST2L+ T cells in PBMCs of HT group was significantly increased when compared to the control group (CON) by Flow cytometry assay. MRNA Expression of IL-33 and ST2 in thyroid tissue and the level of IL-1β and IL-18 were significantly upregulated in HT patients, while IL-5 was down-regulated in HT patients, compared to CON. The expression of IL-1β and IL-18 were positively correlated with the expression of IL-33. Results of western blot and immunohistochemical staining were consistent with qPCR.

Conclusion:

IL-33/ST2 pathway participates in HT via affecting the production of inflammatory cytokines.

IL-33 Prevents MLD-STZ Induction of Diabetes and Attenuate Insulitis in Prediabetic NOD Mice

Type 1 diabetes is an autoimmune disease caused by the immune-mediated destruction of pancreatic β-cells. Prevention of type 1 diabetes requires early intervention in the autoimmune process against beta-cells of the pancreatic islets of Langerhans, which is believed to result from disordered immunoregulation. CD4+Foxp3+ regulatory T cells (Tregs) participate as one of the most important cell types in limiting the autoimmune process. The aim of this study was to investigate the effect of exogenous IL-33 in multiple low dose streptozotocin (MLD-STZ) induced diabetes and to delineate its role in the induction of protective Tregs in an autoimmune attack. C57BL/6 mice were treated i. p. with five doses of 40 mg/kg STZ and 0.4 μg rIL-33 four times, starting from day 0, 6, or 12 every second day from the day of disease induction. 16 weeks old NOD mice were treated with 6 injections of 0.4 μg/mouse IL-33 (every second day). Glycemia and glycosuria were measured and histological parameters in pancreatic islets were evaluated at the end of experiments. Cellular make up of the pancreatic lymph nodes and islets were evaluated by flow cytometry. IL-33 given simultaneously with the application of STZ completely prevented the development of hyperglycemia, glycosuria and profoundly attenuated mononuclear cell infiltration. IL-33 treatment was accompanied by higher number of IL-13 and IL-5 producing CD4+ T cells and increased presence of ST2+Foxp3+ regulatory T cells in pancreatic lymph nodes and islets. Elimination of Tregs abrogated protective effect of IL-33. We provide evidence that exogenous IL-33 completely prevents the development of T cell mediated inflammation in pancreatic islets and consecutive development of diabetes in C57BL/6 mice by facilitating the induction Treg cells. To extend this finding for possible relevance in spontaneous diabetes, we showed that IL-33 attenuate insulitis in prediabetic NOD mice.

Effects of Tocilizumab Therapy on Serum Interleukin-33 and Interleukin-6 Levels in Patients With Rheumatoid Arthritis

Objectives

This study aims to examine the effects of tocilizumab therapy on serum levels of interleukin (IL)-33 and IL-6 in rheumatoid arthritis (RA) patients.

Patients and methods

Interleukin-33 and IL-6 levels in serum samples from 83 RA patients (10 males, 73 females; mean age 51.9 years; range, 26 to 77 years) and 12 healthy controls (2 males, 10 females; mean age 52.2 years; range, 39 to 62 years) were compared by cross-sectional, case control analysis. Of the RA patients, 40 received 24 weeks of tocilizumab therapy and were assigned to the prospective cohort. These 40 patients were then divided into two subgroups as responders and non-responders according to the American College of Rheumatology (ACR) 20. The remaining 43 RA patients did not receive tocilizumab therapy. Serum cytokine levels were analyzed at baseline and after 24 weeks of tocilizumab therapy in these patients.

Results

Interleukin-33 and IL-6 concentrations were significantly higher in RA patients than in healthy controls (p<0.001 for both). Serum IL-33 levels in RA patients showed a significant correlation with rheumatoid factor titer (r=0.660, p<0.001), and IL-6 levels showed a significant correlation with high-sensitivity C-reactive protein levels (Spearman's rank correlation coefficient=0.482, p<0.001). Serum IL-33 levels decreased significantly after 24 weeks of tocilizumab therapy (p<0.001); this was particularly marked in ACR20 responders (p<0.001). However, the decrease in non-responders was not significant (p=0.066). Changes in serum IL-6 levels after 24 weeks of tocilizumab therapy were not significant in either ACR20 responders or non-responders.

Conclusion

Serum IL-33 levels in RA patients receiving tocilizumab therapy decreased significantly, particularly in ACR20 responders. Thus, IL-33 may be a useful marker for monitoring responses to tocilizumab therapy.

IL-33-matured dendritic cells promote Th17 cell responses via IL-1β and IL-6

IL-33 is associated with a variety of autoimmune diseases, such as sclerosis, inflammatory bowel disease, and rheumatoid arthritis. Although IL-33 is mainly involved in the induction of Th2 cells, however, the relationship between IL-33 and Th17 cells is still largely unknown. In this study, we investigated the effects of IL-33 on DC-mediated CD4⁺ T cell activation and Th17 cell differentiation because DCs are essential cells for presenting self-antigens to CD4⁺ T cells in autoimmune disease conditions. OT-II mice were injected with IL-33-treated DCs or untreated DCs that were primed by OVA_323-339 peptide, and their Th17 cell responses were compared. Th17 cell population and IL-17 expression levels were significantly increased in draining lymph nodes of mice injected with IL-33-treated DCs, compared with those in mice injected with untreated DCs. IL-33 treatment maturated DCs to present self-antigens and to increase production of proinflammatory cytokines such as IL-1β and IL-6, which have a crucial role in Th17 cell differentiation. We found that the IL-33-matured DCs enhanced the expression of an early T cell activation marker (CD69) and the Th17 master transcription factor (RORγt), but IL-33 did not directly affect CD4⁺ T cell differentiation or increase Th17 polarization. Notably, neutralizing IL-1β and/or IL-6 significantly decreased IL-17 expression levels and Th17 cell population which were increased by the coculture of CD4⁺ T cells with IL-33-matured DCs, indicating that IL-33 may induce Th17 cell responses via IL-1β and IL-6 derived from IL-33-matured DCs.

Application of the adverse outcome pathway (AOP) concept to structure the available in vivo and in vitro mechanistic data for allergic sensitization to food proteins

BACKGROUND

The introduction of whole new foods in a population may lead to sensitization and food allergy. This constitutes a potential public health problem and a challenge to risk assessors and managers as the existing understanding of the pathophysiological processes and the currently available biological tools for prediction of the risk for food allergy development and the severity of the reaction are not sufficient. There is a substantial body of in vivo and in vitro data describing molecular and cellular events potentially involved in food sensitization. However, these events have not been organized in a sequence of related events that is plausible to result in sensitization, and useful to challenge current hypotheses. The aim of this manuscript was to collect and structure the current mechanistic understanding of sensitization induction to food proteins by applying the concept of adverse outcome pathway (AOP).

MAIN BODY

The proposed AOP for food sensitization is based on information on molecular and cellular mechanisms and pathways evidenced to be involved in sensitization by food and food proteins and uses the AOPs for chemical skin sensitization and respiratory sensitization induction as templates. Available mechanistic data on protein respiratory sensitization were included to fill out gaps in the understanding of how proteins may affect cells, cell-cell interactions and tissue homeostasis. Analysis revealed several key events (KE) and biomarkers that may have potential use in testing and assessment of proteins for their sensitizing potential.

CONCLUSION

The application of the AOP concept to structure mechanistic in vivo and in vitro knowledge has made it possible to identify a number of methods, each addressing a specific KE, that provide information about the food allergenic potential of new proteins. When applied in the context of an integrated strategy these methods may reduce, if not replace, current animal testing approaches. The proposed AOP will be shared at the www.aopwiki.org platform to expand the mechanistic data, improve the confidence in each of the proposed KE and key event relations (KERs), and allow for the identification of new, or refinement of established KE and KERs.

Effects of obesity on IL-33/ST2 system in heart, adipose tissue and liver: study in the experimental model of Zucker rats

Suppression of tumorigenicity 2 (ST2) mediates the effect of Interleukin-33 (IL-33). Few data are reported on the relationship between IL-33/ST2 and obesity. We aimed to investigate effects of obesity on IL-33/ST2 system in heart, adipose tissue and liver in a rodent model of obesity. The relationship of cardiac expression of IL-33/ST2 system with natriuretic peptides (NPs) system and inflammatory mediators was also studied. mRNA expression of IL-33/ST2 system was evaluated in cardiac, adipose and hepatic biopsies from obese Zucker rats (O) and controls (CO). Expression levels of sST2 was significantly lower in O rats compared with CO (p<0.05) in all tissues. Besides, the mRNA levels of IL-33 decreased significant in fat of O respect to CO, while, expression levels of ST2L was significantly higher in liver of CO than in O. A strong relationship of IL-33/ST2 with NPs and classical inflammatory mediators was observed in cardiac tissue. Expression of sST2 in cardiac, adipose and liver tissue decreased in O compared with controls, suggesting an involvement for IL-33/ST2 system in molecular mechanisms of obesity. The strong relationships with NP systems and inflammatory mediators could suggest an involvement for IL-33/ST2 in molecular pathways leading to cardiac dysfunction and inflammation associated with obesity.

Deletion of IL-33R attenuates VEGF expression and enhances necrosis in mammary carcinoma

Interleukin-33 (IL-33)/IL-33 receptor (IL-33R, ST2) signaling pathway promotes mammary cancer growth and metastasis by inhibiting anti-tumor immunity. However, the role of IL-33/IL-33R axis in neoangiogenesis and tumor necrosis is not elucidated. Therefore, the aim of this study was to investigate the role of IL-33/IL-33R axis in mammary tumor necrosis. Deletion of IL-33R (ST2) gene in BALB/c mice enhanced tumor necrosis and attenuated tumor growth in 4T1 breast cancer model, which was associated with markedly decreased expression of vascular endothelial growth factor (VEGF) and IL-33 in mammary tumor cells. We next analyzed IL-33, IL-33R and VEGF expression and microvascular density (MVD) in breast tumors from 40 female patients with absent or present tumor necrosis. We found significantly higher expression of IL-33, IL-33R and VEGF in breast cancer tissues with absent tumor necrosis. Both, IL-33 and IL-33R expression correlated with VEGF expression in tumor cells. Further, VEGF expression positively correlated with MVD in perinecrotic zone. Taking together, our data indicate that IL-33/IL-33R pathway is critically involved in mammary tumor growth by facilitating expression of pro-angiogenic VEGF in tumor cells and attenuating tumor necrosis. These data add an unidentified mechanism by which IL-33/IL-33R axis facilitates tumor growth.

A Proteome-Derived Longitudinal Pharmacodynamic Biomarker for Diffuse Systemic Sclerosis Skin

In this study we systematically investigated alterations in the serum proteome of patients with diffuse cutaneous systemic sclerosis and identified differentially expressed proteins that correlated with disease severity. Our goal was to identify a combination of serum proteins that would provide a biological measure for the extent of skin disease and that could be combined into a longitudinal pharmacodynamic biomarker. We found that 16% of the sera proteins analyzed by SOMAscan aptamer technology, from two cohorts of patients with diffuse cutaneous systemic sclerosis, were identified as differentially regulated between diffuse cutaneous systemic sclerosis and controls and correlated with modified Rodnan skin score. This dataset showed tumor necrosis factor-α, IFN-γ, transforming growth factor-β, and IL-13 as potential upstream regulators of the serum protein patterns in the sera of patients with diffuse cutaneous systemic sclerosis. By ELISA, two analytes (ST2 and Spondin-1) best described longitudinal change in modified Rodnan skin score, using linear mixed models. This model was then validated in three independent cohorts. In this study we discovered a large array of proteins not previously associated with systemic sclerosis that provide insight into pathogenesis and potential targets for therapeutic intervention. Furthermore, we show that two of these proteins can be combined to form a robust longitudinal biomarker that might be used in clinical trials to assess changes in diffuse cutaneous systemic sclerosis skin disease over time.

Increased levels of interleukin-33 in gingival crevicular fluids of patients with chronic periodontitis

The purpose of this clinical study is to comparatively investigate the interleukin-33 (IL-33) levels in gingival crevicular fluid (GCF), saliva and plasma of patients with periodontal disease as well as periodontally healthy subjects and the association between these levels and clinical parameters. GCF, saliva and plasma samples were collected from systemically healthy, non-smoker chronic periodontitis patients (CP group, n = 20), gingivitis patients (G group, n = 20) and periodontally healthy control groups (H group, n = 20). Full-mouth clinical periodontal parameters were also recorded. IL-33 levels were determined by ELISA. The total amount of GCF IL-33 was greater in the G and CP groups compared to the H group (p < 0.05). The GCF IL-33 concentration was significantly lower in the CP group than in the H and G groups (p < 0.001). Salivary or plasma IL-33 levels were similar in the study groups. The total amount of GCF IL-33 was positively correlated with the GI, PI and BOP (%) (p < 0.05). Considering the present findings, the increase in total amounts of GCF IL-33 may have a role in the pathogenesis of periodontal disease.

Overexpression of interleukin-33 is associated with poor prognosis of patients with glioma

Interleukin-33 (IL-33) has shown diagnostic and prognostic values in multiple human cancers. However, there is little knowledge on the role of IL-33 in human gliomas and its association with disease prognosis. This study aimed to evaluate the value of IL-33 in the prognosis of glioma patients. The expression of IL-33 was determined and compared in surgical specimens from 86 glioma patients and 16 normal brain tissues. The associations of IL-33 expression with the clinicopathological features and prognosis of glioma patients were assessed. qRT-PCR assay showed higher IL-33 mRNA expression in glioma tissues than in normal brain tissue ( p < 0.001), and significantly higher IL-33 mRNA expression was detected in both low- and high-grade glioma tissues relative to normal brain tissues ( p < 0.001). Western blotting revealed elevated IL-33 protein levels in glioma tissues compared to those in normal brain tissues, and immunohistochemical staining showed higher IL-33 protein expression in glioma tissues than in normal brain tissues. IL-33 expression correlated with the glioma grade ( p < 0.001) and Karnofsky performance status score ( p = 0.024), and the glioma patients with high IL-33 expression had a shorter progression-free survival ( p < 0.001) and overall survival ( p < 0.001) than those with low IL-33 expression. The univariate and multivariate analyses showed that IL-33 overexpression and the glioma grade were independent factors of a poor prognosis in glioma patients. Therefore, IL-33 may be a promising biomarker for the detection of gliomas, and IL-33 expression is useful for predicting the prognosis of the disease.

IL-33 is associated with unfavorable postoperative survival of patients with clear-cell renal cell carcinoma

The aim of this study was to evaluate the potential prognostic significance of interleukin-33 (IL-33) in patients with clear-cell renal cell carcinoma (ccRCC) after surgical resection. In this retrospective research, we enrolled 203 patients with ccRCC undergoing nephrectomy between 2003 and 2004 in a single institution. We recorded clinicopathologic features, overall survival (OS), and recurrence-free survival (RFS) and assessed IL-33 expression by immunohistochemical staining. On such bases, the correlations between IL-33 expression and clinicopathologic features and prognosis were evaluated. A high expression of IL-33 was significantly associated with advanced TNM stage and Fuhrman grade (p = 0.017 and p < 0.001, respectively) in patients with ccRCC. Moreover, multivariate analysis identified IL-33 as an independent prognostic factor of OS for patients with ccRCC after surgery (hazard ratio = 2.050; 95 % CI 1.223-3.447; p = 0.006). The incorporation of IL-33 into the TNM stage and Fuhrman grade might help to refine individual risk stratification. The IL-33 expression may serve as an independent negative predictor of survival for patients with ccRCC after surgery.

Elevated Circulating Interleukin 33 Levels in Stable Renal Transplant Recipients at High Risk for Cardiovascular Events

Background

The Major Adverse Cardiovascular Events calculator (CRCRTR-MACE) estimates the burden of cardiovascular risk in renal transplant recipients (RTR). Our recent study of 95 RTR reported the 7-year median risk of cardiovascular events (CVE) to be 9.97%, ranging from 1.93 to 84.27%. Nearly a third (28.4%) of the cohort was above 20% risk for a CVE. Since interleukins (ILs) as part of the inflammatory response may play a role in the pathogenesis of cardiovascular disease (CVD), we extended this study to identify which ILs are associated with high cardiovascular risk in this population.

Methods

Twenty-two ILs were measured by multiplexed fluorescent bead-based immunoassay in 95 RTR and 56 normal controls. Stepwise analysis after multivariate determination of significant demographic and inflammatory variables was performed between the high and low-CVD risk groups (which were arbitrarily set at scores <10% and ≥20%, respectively). Normalized data was presented as mean ± SD and non-normalized data as median (minimum–maximum). Significance was measured at <0.05.

Results

27.5% of the low-risk and 31.3% of the high-risk groups had mean IL levels above the 95 percentile of the normal control levels. In the non-parametric analysis IL-6, 9, 16, 17 and 33 were significantly higher in the high-risk group compared to the control. Univariate analysis (UVA) of the high-risk group identified IL-33 as the only IL that remained significantly higher than the control and low-risk groups (p = 0.000). The percentage of patients with IL-33 levels above the 90 percentile of control value in the low and high-risk groups were 15.6% and 52.0%, respectively (p<0.002). UVA of factors significant to high IL-33 levels included estimated glomerular filtration rate (eGFR), while diabetes mellitus, serum phosphorus, microalbuminuria and age also remained significant in the multivariate analysis.

Conclusion

Circulating IL-33 level is positively associated with high CRCRTR-MACE score. Diminished eGFR, age, diabetes, serum phosphorus and microalbuminurea demonstrate significant relationship with elevated IL-33 levels, supporting the possible pathognomonic role of IL-33 in the cardiovascular burden in RTR.

IL-33/ST2 involves the immunopathology of ocular toxoplasmosis in murine model

Ocular toxoplasmosis (OT) is the major cause of infective uveitis. Since the eye is a special organ protected by immune privilege, its immune response is different from general organs with Toxoplasma gondii infection. Here, we used Kunming outbred mice to establish OT by intravitreal injection of T. gondii RH strain tachyzoites, IL-33 expression in the eyes was localized by immunostaining, the levels of interleukin (IL)-33 and ST2 (IL-33 receptor) and T-helper (Th)1 and Th2-associated cytokines in the eye and cervical lymph nodes (CLNs) of infected mice were measured, and their correlations were analyzed. Our results showed that the pathologies of the eye and CLN tissues and the IL-33 positive cells in the eye tissues of ocular T. gondii-infected mice were all increased at days 2, 6, and 9 postinfection (p.i.), accompanied with significantly increased transcript levels of IL-33, ST2, IL-1β, IFN-γ, IL-12p40, IL-10, and IL-13 in both the eyes and CLNs, and increased IL-4 expressions in the eyes of T. gondii-infected mice. There were significant correlations between the levels of IFN-γ and ST2, IL-4 and ST2, and IL-13 and ST2 in the eye tissues (P < 0.001), significant correlations between the levels of IFN-γ and ST2 (P < 0.001) as well as between IL-13 and ST2 (P < 0.05) in the CLNs, and significant correlations between the levels of IL-1β and IL-33 in the eyes (P < 0.05) and between IL-1β and IL-33/ST2 in the CLNs (P < 0.001 and P < 0.01, respectively). Our data indicated that IL-33/ST2 may involve the regulation of ocular immunopathology induced by T. gondii infection.

Regulatory T cells produce profibrotic cytokines in the skin of patients with systemic sclerosis

BACKGROUND

Systemic sclerosis (SSc) is an autoimmune disorder characterized by fibrosis of the skin and internal organs. Pathologic conversion of regulatory T (Treg) cells into inflammatory cytokine-producing cells is thought to be an important step in the progression of autoimmunity, but whether loss of normal Treg cell function contributes to SSc is unknown.

OBJECTIVE

We sought to determine whether Treg cells in the blood and skin of patients with SSc acquired abnormal production of effector cytokines.

METHODS

Peripheral blood and skin biopsy specimens were collected from control subjects and patients with limited or diffuse SSc. Flow cytometry was used to evaluate expression of cell-surface proteins and the cytokine production profile of forkhead box protein 3-positive Treg cells compared with forkhead box protein 3-negative conventional T cells.

RESULTS

Treg cells in the blood of patients with SSc had a normal phenotype and did not produce T-effector cytokines. In contrast, Treg cells from skin affected by SSc produced significant amounts of IL-4 and IL-13. Although Treg cells in the blood of patients with SSc did not make TH2 cytokines, they contained a significantly higher proportion of skin-homing cells expressing TH2 cell-associated chemokine receptors. Evidence that IL-33 caused the differentiation of skin Treg cells into TH2-like cells, combined with high tissue-localized expression of this cytokine in patients with SSc and expression of the ST2 chain of the IL-33 receptor on skin-localized Treg cells, suggests that IL-33 might be an important stimulator of tissue-localized loss of normal Treg cell function.

CONCLUSION

These data are the first evidence for the presence of TH2-like Treg cells in human autoimmunity and show that Treg cell plasticity can be tissue specific. Localized dysfunction of Treg cells is a previously unknown factor that might contribute to fibrosis in patients with SSc.