IL-35 recombinant protein reverses inflammatory bowel disease and psoriasis through regulation of inflammatory cytokines and immune cells

Cytokines in psoriasis: From pathogenesis to targeted therapy

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

Lactococcus lactis as an Interleukin Delivery System for Prophylaxis and Treatment of Inflammatory and Autoimmune Diseases

Target delivery of therapeutic agents with anti-inflammatory properties using probiotics as delivery and recombinant protein expression vehicles is a promising approach for the prevention and treatment of many diseases, such as cancer and intestinal immune disorders. Lactococcus lactis, a Lactic Acid Bacteria (LAB) widely used in the dairy industry, is one of the most important microorganisms with GRAS status for human consumption, for which biotechnological tools have already been developed to express and deliver recombinant biomolecules with anti-inflammatory properties. Cytokines, for  example, are immune system communication molecules present at virtually all levels of the immune response. They are essential in cellular and humoral processes, such as hampering inflammation or adjuvating in the adaptive immune response, making them good candidates for therapeutic approaches. This review discusses the advances in the development of new therapies and prophylactic approaches using LAB to deliver/express cytokines for the treatment of inflammatory and autoimmune diseases in the future.

A glance on the role of IL-35 in systemic lupus erythematosus (SLE)

It is well known that systemic lupus erythematosus (SLE) is an auto-inflammatory disease that is characterized by chronic and widespread inflammation. The exact pathogenesis of SLE is still a matter of debate. However, it has been suggested that the binding of autoantibodies to autoantigens forms immune complexes (ICs), activators of the immune response, in SLE patients. Ultimately, all of these responses lead to an imbalance between anti-inflammatory and pro-inflammatory cytokines, resulting in cumulative inflammation. IL-35, the newest member of the IL-12 family, is an immunosuppressive and anti-inflammatory cytokine secreted mainly by regulatory cells. Structurally, IL-35 is a heterodimeric cytokine, composed of Epstein-Barr virus-induced gene 3 (EBI3) and p35. IL-35 appears to hold therapeutic and diagnostic potential in cancer and autoimmune diseases. In this review, we summarized the most recent associations between IL and 35 and SLE. Unfortunately, the comparative review of IL-35 in SLE indicates many differences and contradictions, which make it difficult to generalize the use of IL-35 in the treatment of SLE. With the available information, it is not possible to talk about targeting this cytokine for the lupus treatment. So, further studies would be needed to establish the clear and exact levels of this cytokine and its related receptors in people with lupus to provide IL-35 as a preferential therapeutic or diagnostic candidate in SLE management.

IL-35: New Target for Immunotherapy Targeting the Tumor Microenvironment

Interleukin 35(IL-35) is a newly discovered inhibitory cytokine of the IL12 family. More recently, IL-35 was found to be increased in the tumor microenvironment (TME) and peripheral blood of many patients with cancer, indicating that it plays an important role in the TME. Tumors secrete cytokines that recruit myeloid-derived suppressor cells (MDSCs) and regulatory T cells (Treg) into the TME to promote malignant progression, which is a great challenge for cancer treatment. Radiotherapy causes serious adverse effects, and tumor resistance to immune checkpoint inhibitors is still an unsolved challenge. Thus, new cancer therapy approaches are urgently needed. Numerous studies have shown that IL-35 can recruit immunosuppressive cells to enable tumor immune escape by promoting the conversion of immune cells into a tumor growth-promoting phenotype as well as facilitating tumor angiogenesis. IL-35-neutralizing antibodies were found to boost the chemotherapeutic effect of gemcitabine and considerably reduce the microvascular density of pancreatic cancer in mice. Therefore, targeting IL-35 in the TME provides a promising cancer treatment target. In addition, IL-35 may be used as an independent prognostic factor for some tumors in the near future. This review intends to reveal the interplay of IL-35 with immune cells in the TME, which may provide new options for the treatment of cancer.

Dual function of fungi-derived cytokines in inflammatory bowel diseases: protection or inflammation

Inflammatory bowel disease (IBD) is an immune-mediated inflammatory condition involving both the innate and adaptive immune systems. Recently, the role of intestinal fungal flora and their downstream immune pathways has been highlighted in the pathogenesis of IBD. Cytokines as primary immune mediators require a delicate balance for maintaining intestinal homeostasis. Although most cytokines have a predictable role in either amplifying or attenuating inflammation in IBD, a few cytokines have shown a dual function in the inflammatory state of the intestine. Some of these dual-faced cytokines are also involved in mucosal anti-microbial defense pathways, particularly against intestinal fungal residents. Here, we reviewed the role of these cytokines in IBD pathogenesis to achieve a better understanding of the fungal interactions in the development of IBD.

Regulatory B cells induced by interleukin-35 inhibit inflammation and alveolar bone resorption in ligature-induced periodontitis

BACKGROUND

Regulatory B cells (Bregs) have been reported to suppress immune responses and alveolar bone loss in murine periodontitis models. These cells could be induced by interleukin (IL)-35 which is increased upon periodontal inflammation. Thus, this study aimed to explore the role of Bregs induced by IL-35 in periodontitis.

METHODS

Experimental periodontitis was induced in mice by ligature. Two weeks after ligation, the test group was systemically treated with IL-35 for 1 week. Four weeks after ligation, all mice were euthanized, and alveolar bone loss was evaluated by microcomputed tomography. Cytokines associated with periodontitis were analyzed using reverse transcription-quantitative polymerase chain reaction and enzyme-linked immunosorbent assay. Bregs in spleens, cervical lymph nodes, and periodontal tissues were detected by flow cytometry and immunofluorescence staining.

RESULTS

In the mouse model of periodontitis, IL-35 induced the expansion of CD1dhi CD5+ B10 cells with increased interleukin-10 (IL-10) and IL-35 production. IL-35 administration also attenuated alveolar bone loss and reduced the levels of proinflammatory cytokines in situ.

CONCLUSIONS

Following ligature-induced periodontitis in mice, IL-35 inhibited periodontal inflammation and alveolar bone resorption at least partially through the induction of B10 cells and IL-35+ Bregs.

The yin and yang of B cells in a constant state of battle: intestinal inflammation and inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic inflammatory disease of the gastrointestinal tract, defined by a clinical relapse-remitting course. Affecting people worldwide, the origin of IBD is still undefined, arising as a consequence of the interaction between genes, environment, and microbiota. Although the root cause is difficult to identify, data clearly indicate that dysbiosis and pathogenic microbial taxa are connected with the establishment and clinical course of IBD. The composition of the microbiota is shaped by plasma cell IgA secretion and binding, while cytokines such as IL10 or IFN-γ are important fine-tuners of the immune response in the gastrointestinal environment. B cells may also influence the course of inflammation by promoting either an anti-inflammatory or a pro-inflammatory milieu. Here, we discuss IgA-producing B regulatory cells as an anti-inflammatory factor in intestinal inflammation. Moreover, we specify the context of IgA and IgG as players that can potentially participate in mucosal inflammation. Finally, we discuss the role of B cells in mouse infection models where IL10, IgA, or IgG contribute to the outcome of the infection.

Co-induced Allergic Response to an Unrelated Allergen Exacerbates Imiquimod-Induced Psoriasis in Mice

Psoriasis is classically regarded as a T-helper 1 (Th1) response-dominant disease believed to be antagonized by the Th2 response, which is responsible for allergic diseases, such as atopic dermatitis. The roles of these responses in psoriasis and the relationship between psoriasis and atopic dermatitis have received increasing attention because it is estimated that more than one million patients are concomitantly affected by psoriasis and atopic dermatitis. To address this, we attempted to determine the characteristics of imiquimod-induced psoriasiform lesions in mice with a concomitant allergic response after co-application of the unrelated allergen ovalbumin onto the skin. Imiquimod cream containing ovalbumin was successively applied to the right back skin of hairless HR female mice. Psoriasiform scores were determined for 11 d, and then, the resected skin thickness, spleen weight, and serum antibody levels were examined. In some experiments, mice were allowed free access to ovalbumin-containing water for 10 d before skin application to induce oral tolerance. Imiquimod cream induced psoriasis, and its severity increased upon simultaneous ovalbumin treatment. Increases in anti-ovalbumin immunoglobulin G2a (IgG2a) levels, a Th1 response indicator, and IgG1 and IgE levels, Th2 response indicators, were mediated by ovalbumin addition. Oral tolerance against ovalbumin effectively decreased ovalbumin-exacerbated imiquimod-induced psoriasis, in parallel with a decrease in levels of anti-ovalbumin antibodies. These results suggest that the concomitant allergic response induced by ovalbumin application exacerbates imiquimod-induced psoriasis. This implies that allergic responses to unrelated allergens might exacerbate psoriasis in humans and that modulating such responses could be an effective new approach to treat psoriasis.

Hypoxia in the Pathophysiology of Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is an idiopathic disease of disordered chronic inflammation in the intestines that affects many people across the world. While the disease is still being better characterized, greater progress has been made in understanding the many components that intersect in the disease. Among these components are the many pieces that compose the intestinal epithelial barrier, the various cytokines and immune cells, and the population of microbes that reside in the intestinal lumen. Since their discovery, the hypoxia-inducible factors (HIFs) have been found to play an expansive role in physiology as well as diseases such as inflammation due to their role in oxygen sensing-related gene transcription, and metabolic control. Making use of existing and developing paradigms in the immuno-gastroenterology of IBD, we summarized that hypoxic signaling plays as another component in the status and progression of IBD, which may include possible functions at the origins of inflammatory dysregulation. © 2023 American Physiological Society. Compr Physiol 13:4767-4783, 2023.

The immunoregulatory role of IL-35 in patients with interstitial lung disease

Pulmonary fibrosis involves various types of immune cells and soluble mediators, including TGF-β and IL-35, a recently identified heterodimeric cytokine that belongs to the IL-12 cytokine family. However, the effect of regulatory IL-35 may play an important role in fibrotic diseases. The aim of this paper is to explore the immunoregulatory role of IL-35 in the development of fibrosis in interstitial lung disease (ILD). To gain a better understanding of this issue, the concentrations of IL-35 and different profibrotic cytokines in fibrotic (F-ILD) and non-fibrotic (NF-ILD) patients by ELISA were compared to that of intracellular IL-35 and IL-17 on CD4+ T cells stimulated in the presence of BAL or with different ratios of recombinant IL-35 (rIL-35) and TGF-β (rTGF-β), which were evaluated by flow cytometry. We observed that BAL concentration of IL-35 was lower in F patients (p < 0.001) and was negatively correlated with concentrations of TGF-β (p < 0.001) and IL-17 (p < 0.001). In supplemented cell cultures, BAL from NF but not F patients enhanced the percentage of IL-35 + CD4+ T (p < 0.001) cells and decreased the percentage of IL-17 + CD4+ T cells (p < 0.001). The percentage of IL-35 + CD4+ T cells correlated positively with BAL concentration of IL-35 (p = 0.02), but correlated negatively with BAL concentrations of IL-17 (p = 0.007) and TGF-β (p = 0.01). After adjusting the concentrations of recombinant cytokines to establish a TGF-β: IL-35 ratio of 1:4, an enhanced percentage of IL-35 + CD4+ T cells (p < 0.001) but a decreased percentage of IL-17 + CD4+ T cells (p < 0.001) was observed. After adding recombinant IL-35 to the BAL from F patients until a 1:4 ratio of TGF-β: IL-35 was reached, a significantly increased percentage of IL-35 + CD4+ T cells (p < 0.001) and a decreased percentage of IL-17 + CD4+ T cells (p = 0.003) was found. These results suggest that IL-35 may induce an anti-fibrotic response, regulating the effect of TGF-β and the inflammatory response on CD4+ T cells. In addition, the TGF-β: IL-35 ratio in BAL has been shown to be a potential biomarker to predict the outcome of F patients with ILD.

Inducible nitric oxide synthase-expressing myeloid-derived suppressor cells regulated by interleukin 35 contribute to the pathogenesis of psoriasis

Although psoriasis is classified as a T cell-mediated inflammatory disease, the contribution of myeloid cells to the pathogenesis of psoriasis is not fully understood. In the present study, we demonstrated that the expression of the anti-inflammatory cytokine interleukin-35 (IL-35) was significantly increased in patients with psoriasis with a marked increase in the number of myeloid-derived suppressor cells (MDSCs). Similar results were obtained in an imiquimod-induced psoriasis mouse model. IL-35 reduced the total number of MDSCs and their subtypes in the spleens and psoriatic skin lesions, ameliorating psoriasis. IL-35 also reduced the expression of inducible nitric oxide synthase in MDSCs, although it had no significant effect on interleukin-10 expression. Adoptive transfer of MDSCs from imiquimod-challenged mice aggravated the disease and weakened the effect of IL-35 in the recipient mice. In addition, mice transferred with MDSCs isolated from inducible nitric oxide synthase knockout mice had milder disease than those with wild-type MDSCs. Furthermore, wild-type MDSCs reversed the effects of IL-35, while MDSCs isolated from inducible nitric oxide synthase knockout mice did not affect IL-35 treatment. In summary, IL-35 may play a critical role in the regulation of iNOS-expressing MDSCs in the pathogenesis of psoriasis, highlighting IL-35 as a novel therapeutic strategy for patients with chronic psoriasis or other cutaneous inflammatory diseases.

Regulatory T-cell stability and functional plasticity in health and disease

FOXP3-expressing regulatory T cells (T_reg ) are indispensable for immune homeostasis and tolerance, and in addition tissue-resident T_reg have been found to perform noncanonical, tissue-specific functions. For optimal tolerogenic function during inflammatory disease, T_reg are equipped with mechanisms that assure lineage stability. T_reg lineage stability is closely linked to the installation and maintenance of a lineage-specific epigenetic landscape, specifically a T_reg -specific DNA demethylation pattern. At the same time, for local and directed immune regulation T_reg must possess a level of functional plasticity that requires them to partially acquire T helper cell (T_H ) transcriptional programs-then referred to as T_H -like T_reg . Unleashing T_H programs in T_reg , however, is not without risk and may threaten the epigenetic stability of T_reg with consequently pathogenic ex-T_reg contributing to (auto-) inflammatory conditions. Here, we review how the T_reg -stabilizing epigenetic landscape is installed and maintained, and further discuss the development, necessity and lineage instability risks of T_H 1-, T_H 2-, T_H 17-like T_reg and follicular T_reg .

Interleukin 17 B regulates colonic myeloid cell infiltration in a mouse model of DSS-induced colitis

Cytokines play vital roles in the pathogenesis of inflammatory bowel disease. IL17B is protective in the development of colitis. However, how IL17B regulates intestinal inflammation and what cells are regulated by IL17B is still unknown. Here, we aimed to illustrate the IL17B dependent cellular and molecular changes in colon tissue in a mouse colitis model. The results showed that IL17B expression in colon tissues was elevated in inflamed tissues than non-inflamed tissues of IBD patients. Wild type (WT) and Il17b deficient (Il17b ^-/-) mice were given 2.5% dextran sodium sulfate (DSS) water, and in some case, Il17b ^-/- mice were treated with recombinant mouse IL17B. IL17B deficiency resulted in severe DSS-induced colitis with exaggerated weight loss, shorter colon length, and elevated proinflammatory cytokines in colon. Reconstitution of Il17b ^-/- mice with recombinant IL17B alleviated the severity of DSS-induced colitis. Single cell transcriptional analyses of CD45⁺ immune cells in colonic lamina propria revealed that loss of IL17B resulted in an increased neutrophil infiltration and enhanced inflammatory cytokines in intestinal macrophages in colitis, which were confirmed by real-time PCR and flow cytometry. IL17B treatment also inhibited lipopolysaccharide-induced inflammation in bone marrow-derived macrophages and mice. IL17B inhibits colitis by regulating colonic myeloid cell response. It might represent a novel potential therapeutic approach to treat the colitis.

[WDSUB1 knockdown alleviates dextran sulfate sodium-induced colitis in mice by inhibiting nuclear factor-κB signaling pathway]

OBJECTIVE

To explore the effect of WDSUB1 on dextran sulfate sodium (DSS)-induced inflammatory colon injury in mice and the underlying mechanism.

METHODS

Different WDSUB1 siRNA sequences were transfected into mouse fibroblast L929 cells and the optimal sequence was selected by Western blotting. Twelve male C57BL/6 mice were randomized into two groups for injection of siWDSUB1 or siControl via the caudal vein, followed by treatment with 2.5% DSS in drinking water to establish mouse models of DSS- induced colitis (n=6). The expression level of WDSUB1 in the colon tissue of the mice was detected with Western blotting and RT-PCR, the changes in body weight and fecal condition were recorded, and the clinical symptoms of the mice were evaluated. The mRNA expression levels of IL-6, COX-2 and TNF-α and the protein expression of IκBα and P65 in the colon tissues were detected with RT- PCR and Western blotting, respectively.

RESULTS

The mRNA and protein expressions of WDSUB1 in the colon tissues were significantly lower in colitis mice with WDSUB1 knock-down than in the control mice. Compared with the control mice, the mice receiving siWDSUB1 injection showed obviously milder weight loss, diarrhea and hematochezia with significantly lower mRNA expressions of COX2, IL-6 and TNFα (P < 0.05) and protein expression of IκBα but without obvious changes in P65 expression in the colon tissue.

CONCLUSION

WDSUB1 knockdown can alleviate DSS- induced colitis in mice possibly by inhibiting the NF-κB signaling pathway and decreasing the expression of inflammatory factors in the colon tissues.

The Molecular Role of IL-35 in Non-Small Cell Lung Cancer

Non-small cell lung cancer (NSCLC) is the most common type of lung cancer and a common cause of cancer-related death. Better understanding of the molecular mechanisms, pathogenesis, and treatment of NSCLC can help improve patient outcomes. Significant progress has been made in the treatment of NSCLC, and immunotherapy can prolong patient survival. However, the overall cure and survival rates are low, especially in patients with advanced metastases. Interleukin-35 (IL-35), an immunosuppressive factor, is associated with the onset and prognosis of various cancers. Studies have shown that IL-35 expression is elevated in NSCLC, and it is closely related to the progression and prognosis of NSCLC. However, there are few studies on the mechanism of IL-35 in NSCLC. This study discusses the role of IL-35 and its downstream signaling pathways in the pathogenesis of NSCLC and provides new insights into its therapeutic potential.

Interleukin-35 in autoimmune dermatoses: Current concepts

Interleukin-35 (IL-35) is a lately observed cytokine and is part of the IL-12 cytokine family. IL-35 includes two subunits, p35 and Epstein-Barr virus-induced gene 3, and activates subsequent signaling pathways by binding to receptors to mediate signal transduction, thereby modulating the immunoregulatory functions of T cells, B cells, macrophages, and other immune cell types. Although there is currently limited research on the roles of IL-35 in human autoimmunity, many studies have demonstrated that IL-35 may mediate immunosuppression. Therefore, it plays an essential role in some autoimmune dermatoses, including systemic lupus erythematosus, psoriasis, systemic sclerosis, and dermatomyositis. We will introduce the structure and biological characteristics of IL-35 and summarize its effects on the occurrence and development of autoimmune dermatoses in this article. It is suggested that IL-35 is a possible target for therapy in the aforementioned diseases.

Cow Milk Extracellular Vesicle Effects on an In Vitro Model of Intestinal Inflammation

Extracellular vesicles (EVs) are lipid bilayer nano-dimensional spherical structures and act mainly as signaling mediators between cells, in particular modulating immunity and inflammation. Milk-derived EVs (mEVs) can have immunomodulatory and anti-inflammatory effects, and milk is one of the most promising food sources of EVs. In this context, this study aimed to evaluate bovine mEVs anti-inflammatory and immunomodulating effects on an in vitro co-culture (Caco-2 and THP-1) model of intestinal inflammation through gene expression evaluation with RT-qPCR and cytokine release through ELISA. After establishing a pro-inflammatory environment due to IFN-γ and LPS stimuli, CXCL8, IL1B, TNFA, IL12A, IL23A, TGFB1, NOS2, and MMP9 were significantly up-regulated in inflamed Caco-2 compared to the basal co-culture. Moreover, IL-17, IL-1β, IL-6, TNF-α release was increased in supernatants of THP-1. The mEV administration partially restored initial conditions with an effective anti-inflammatory activity. Indeed, a decrease in gene expression and protein production of most of the tested cytokines was detected, together with a significant gene expression decrease in MMP9 and the up-regulation of MUC2 and TJP1. These results showed a fundamental capability of mEVs to modulate inflammation and their potential beneficial effect on the intestinal mucosa.

Correlation Analysis Among the Level of IL-35, Microvessel Density, Lymphatic Vessel Density, and Prognosis in Non-Small Cell Lung Cancer

The aim of this study was to determine the expression of IL‐35 and the lymphatic vessel density (LVD) and microvessel density (MVD) in the pathological tissues from patients with non‐small cell lung cancer (NSCLC) and to analyze their correlation with other common clinical prognostic factors, as well as patients’ overall survival and progression‐free survival. We analyzed the pathological characteristics of 130 patients with NSCLC and determined the IL‐35 expression, MVD, and LVD changes in the pathological tissues by immunohistochemistry. The results showed that IL‐35 expression was significantly correlated with tumor differentiation, lymph node metastasis, T staging, LVD, and MVD (P < 0.05) but was not associated with age, sex, smoking, and other factors. Univariate analysis of risk models showed that age, lymph node metastasis, T stage, and high IL‐35 expression, LVD, and MVD were significantly associated with NSCLC prognosis (P < 0.05), whereas sex, smoking, and high differentiation were not correlated with prognosis. Multivariate analysis of the proportional risk model showed that the IL‐35 expression, lymph node metastasis, high LVD, and high MVD were significantly correlated with NSCLC prognosis (P < 0.05). In conclusion, IL‐35, MVD, and LVD may be independent prognostic markers. In addition, IL‐35 might represent a promising clinical drug target for the treatment of NSCLC.

Serum level of interleukin-35 as a potential prognostic factor for gastric cancer

AIMS

Interleukin-35 (IL-35), a novel anti-inflammatory cytokine, has recently been implicated in tumor development, progression, and survival. However, the relationship between serum IL-35 levels and gastric cancer (GC) is inconclusive. Here, we performed this study to clarify the role of serum level of IL-35 in GC patients.

METHODS

We enrolled 180 GC patients and 170 healthy controls and used enzyme-linked immunosorbent assay to detect serum IL-35 levels. The clinical relevance between IL-35 and clinical pathology parameters was assessed. Univariate and multivariate logistic regressions were used to determine the feasibility of IL-35 as a clinical biomarker.

RESULTS

We observed that serum IL-35 levels were significantly higher in GC patients (17.559 ± 13.266 pg/mL) than in healthy controls (8.077 ± 3.801 pg/mL, P < .001). High serum IL-35 levels were significantly associated with clinical stage (P = .048) and Helicobacter pylori (HP) infection (P < .001). The Kaplan-Meier survival analysis indicated that patients in the high-IL-35 group had poor overall survival (OS) and progression-free survival (PFS) (median OS: 26.0 vs 36.0 months, P < .001; median PFS: 18.0 vs.26.0 months, P = .044). Multivariate analyses demonstrated that serum IL-35 was an independent prognostic factor for GC (OS: hazard ratio [HR] = 1.031 [95% CI, 1.017-1.045], P < .001; PFS: HR = 1.029 [95% CI, 1.015-1.043], P < .001).

CONCLUSIONS

High serum IL-35 levels are associated with poor disease prognosis in GC patients, and it may be become a new and promising biomarker for prognosis of gastric cancer.

Pretreatment with interleukin 35-engineered mesenchymal stem cells protected against lipopolysaccharide-induced acute lung injury via pulmonary inflammation suppression

Acute lung injury (ALI)-triggered pulmonary injury has been associated with high mortality, despite advances in drug treatment and supportive therapy. Remarkable progress has been made in attenuating the inflammatory injury associated with ALI using mesenchymal stem cells (MSCs)-based cell and gene therapy. However, to date, the benefits of interleukin-35 (IL-35)-modified MSCs in ALI intervention have not been investigated. In the present study, adult male C57BL/6 mice randomly received intravenous infusion of adipose-derived mesenchymal stem cells (ADSCs) constitutively expressing IL-35 (IL-35-GFP-ADSCs) or GFP (GFP-ADSCs) via retrovirus-mediated transduction (8 × 10⁵ cells per mice) or isotonic saline 7 days before ALI modeling to investigate the effect and related mechanism. ALI was performed by lipopolysaccharide (LPS) inhalation for 24 h. Normal mice served as the sham group. The results indicated that compared with GFP-ADSCs, IL-35-modified ADSCs significantly increased cellular and pulmonary IL-10 and IL-35 production. Pretreatment with IL-35-ADSCs markedly reduced body weight loss, pulmonary wet/dry weight ratio and pathological injury. The PO₂ was rescued to normal levels in mice that received IL-35-ADSCs. IL-35-ADSCs infusion apparently inhibited IL-6 release, protein leakage and MPO activity but greatly elevated IL-35 level in the bronchoalveolar lavage fluid (BALF). Splenic regulatory T cells in IL-35-ADSCs-pretreated mice got effective increase. Moreover, IL-35-ADSCs pretreatment remarkably inhibited neutrophil and macrophage infiltration and greatly decreased IL-6, tumor necrosis factor α (TNF-α) and Toll-like receptor 4 (TLR4) expression. In conclusion, pretreatment with IL-35-engineered ADSCs provided effective protection against LPS-induced ALI through suppression of pulmonary inflammation and, thus, might be a promising strategy to improve outcomes after ALI. The enhanced paracrine and immunosuppressive capacity of IL-35-ADSCs might contribute to their beneficial effects. However, further studies are needed to illuminate the detailed mechanism.

Lower serum interleukin-22 and interleukin-35 levels are associated with disease status in neuromyelitis optica spectrum disorders

AIMS

The exact pathogenesis of neuromyelitis optica spectrum disorder (NMOSD) remains unclear. A variety of cytokines are involved, but few studies have been performed to explore the novel roles of interleukin-22 (IL-22) and interleukin-35 (IL-35) in NMOSD. Therefore, this study was designed to investigate serum levels of IL-22 and IL-35, and their correlations with clinical and laboratory characteristics in NMOSD.

METHODS

We performed a cross-section study, 18 patients with acute NMOSD, 23 patients with remission NMOSD, and 36 healthy controls were consecutively enrolled. Serum levels of IL-22 and IL-35 were measured by enzyme-linked immunosorbent assay (ELISA). The correlations between serum IL-22 and IL-35 levels and clinical and laboratory characteristics were evaluated by Spearman's rank or Pearson's correlation coefficient.

RESULTS

The serum levels of IL-22 and IL-35 were significantly lower in patients with acute NMOSD and remission NMOSD than in healthy controls (IL-22: 76.96 ± 13.62 pg/mL, 87.30 ± 12.79 pg/mL, and 94.02 ± 8.52 pg/mL, respectively, P < .0001; IL-35: 45.52 ± 7.04 pg/mL, 57.07 ± 7.68 pg/mL, and 60.05 ± 20.181 pg/mL, respectively, P < .0001). Serum levels of IL-35 were negatively correlated with EDSS scores and cerebrospinal fluid protein levels (r = -.5438, P = .0002 and r = -.3523, P = .0258, respectively) in all patients.

CONCLUSIONS

Lower serum levels of IL-22 and IL-35 are associated with disease status in NMOSD. Additionally, lower serum levels of IL-35 are associated with disease severity in NMOSD.

Epigenetic histone modulation contributes to improvements in inflammatory bowel disease via EBI3

Ulcerative colitis (UC) is characterized by relapsing–remitting inflammatory episodes paralleled by varying cytokine levels, suggesting that switching epigenetic processes might be involved. However, the epigenetic impact on cytokine levels in colitis is mostly unexplored. The heterodimeric interleukin (IL)-12 cytokine family have various functions in both pro- and anti-inflammatory processes. The family member IL-35 (EBI3/IL-12p35) was recently reported to play an anti-inflammatory role in UC. Therefore, we aimed to investigate a possible epigenetic regulation of the IL-35 subunits in vitro and in vivo, and to examine the epigenetic targeting of EBI3 expression as a therapeutic option for UC. Exposure to either the pro-inflammatory TNFα or to histone deacetylase inhibitors (HDACi) significantly increased EBI3 expression in Human Colon Epithelial Cells (HCEC) generated from healthy tissue. When applied in combination, a drastic upregulation of EBI3 expression occurred, suggesting a synergistic mechanism. Consequently, IL-35 was increased as well. In vivo, the intestines of HDACi-treated wild-type mice exhibited reduced pathological signs of colitis compared to non-treated colitic mice. However, the improvement by HDACi treatment was completely lost in Ebi3-deficient mice (Ebi3^−/−). In fact, HDACi appeared to exacerbate the disease phenotype in Ebi3^−/−. In conclusion, our results reveal that under inflammatory conditions, EBI3 is upregulated by the epigenetic mechanism of histone acetylation. The in vivo data show that the deficiency of EBI3 plays a key role in colitis manifestation. Concordantly, our data suggest that conditions promoting histone acetylation, such as upon HDACi application, improve colitis by a mechanism involving the local formation of the anti-inflammatory cytokine IL-35.

Interleukin (IL)-35 Suppresses IL-6 and IL-8 Production in IL-17A-Stimulated Human Periodontal Ligament Cells

Interleukin (IL)-35 is a novel anti-inflammatory cytokine that is produced by regulatory T cells. IL-35 is reported to suppress IL-17A-producing helper T (Th17) cell activation. IL-17A is related to progression of periodontitis. Furthermore, IL-35 and IL-17A are detected in human gingival crevicular fluid. However, the effect of IL-35 and interaction between IL-35 and IL-17A on pro-inflammatory cytokine production in human periodontal resident cells are still unclear. The aim of this study was to clarify the effect of IL-35 on IL-6 and IL-8 production in human periodontal ligament cells (HPDLCs) stimulated with IL-17A. IL-35 inhibited IL-6 and IL-8 production in IL-17A-stimulated HPDLCs. Moreover, western blot analysis showed that IL-35 suppressed extracellular signal-regulated kinase (ERK) and nuclear factor (NF)-κB p65 phosphorylation in IL-17A-stimulated HPDLCs. Our findings suggested that IL-35 produced from regulatory T cells might inhibit progression of periodontitis by decreasing IL-17A-induced levels of IL-6 and IL-8.

Preventative delivery of IL-35 by Lactococcus lactis ameliorates DSS-induced colitis in mice

Ulcerative colitis (UC) is one of the two major forms of inflammatory bowel disease (IBD) characterized by superficial mucosal inflammation, rectal bleeding, diarrhea, and abdominal pain. Anti-inflammatory and immunosuppressive drugs have been used in the therapy of human UC. Interleukin (IL)-35, which functions as an anti-inflammatory cytokine, has been shown to play a potential therapeutic role in a UC-like mouse colitis induced by dextran sodium sulfate (DSS). However, the contribution of IL-35 via oral administration to colitis prevention has not been determined. In order to explore its preventative potentiality, a dairy Lactococcus lactis NZ9000 strain was engineered to express murine IL-35 (NZ9000/IL-35), and this recombinant bacteria was applied to prevent and limit the development of DSS-induced mouse colitis. We found that oral administration of NZ9000/IL-35 induced the accumulation of IL-35 in the gut lumen of normal mice. When administrated preventatively, NZ9000/IL-35-gavaged mice exhibited decreased weight loss, DAI score, colon shortening as well as colitis-associated histopathological changes in colon, indicating that the oral administration of NZ9000/35 contributed to the suppression of DSS-induced colitis progression. Moreover, much less Th17 cells and higher level of Treg cells in lamina propria, as well as increased colon and serum levels of IL-10 with a concomitant reduced pro-inflammatory cytokines, IL-6, IL-17A, IFN-γ, and TNF-α were apparently regulated by NZ9000/IL-35 in colitis mice. Together, we put forward direct evidence pinpointing the effectiveness of NZ9000/IL-35 in preventing UC-like mouse colitis, implying a potential candidate of this recombinant Lactococcus lactis that prevent the progression of IBD.

Correlation between Serum IL-35 Levels and Bone Loss in Postmenopausal Women with Rheumatoid Arthritis

Objective

IL-35 was reported as a crucial anti-inflammatory cytokine and could efficiently regulate bone metabolism in murine collagen-induced arthritis model. However, the relationship between IL-35 and bone health in human rheumatoid arthritis (RA) has not been clarified. In this study, the aim was to explore the correlations between IL-35 and bone loss in postmenopausal women with RA.

Methods

The study included 76 postmenopausal women with RA and 53 healthy postmenopausal women as healthy controls (HCs). Serum IL-35 levels were detected by enzyme-linked immunosorbent assay. Bone mineral density (BMD) at lumbar spine 1-4 and at total hip was measured using dual-energy X-ray absorptiometry. Alkaline phosphatase (ALP), β-isomerised carboxy-terminal cross-linking telopeptide of type I collagen (β-CTX), and 25-(OH) VitD₃ were measured by turbidimetric inhibition immunoassay.

Results

Serum IL-35 levels were increased compared with HCs, and it positively correlated with BMD and 25-(OH) VitD₃ and negatively correlated with β-CTX in postmenopausal women with RA. Furthermore, serum IL-35 levels in the increased ALP group were higher than those in the normal ALP group.

Conclusions

IL-35, an important anti-inflammatory cytokine, may participate in the pathogenesis of bone loss in postmenopausal women with RA.

IL-35 alleviates inflammation progression in a rat model of diabetic neuropathic pain via inhibition of JNK signaling

Background

Emerging evidence has demonstrated that inflammation is involved in the occurrence and development of diabetic neuropathic pain (DNP). The anti-inflammatory property of interleukin (IL)-35 makes it a promising candidate to block the pain perception. The present study was undertaken to investigate whether IL-35 could attenuate DNP in streptozotocin (STZ)-induced rat model and its potential mechanism.

Methods

The rat model of DNP was established by a single STZ injection followed by measurements of fasting blood glucose and insulin. Fourteen days after STZ injection, DNP rats were intrathecally injected with IL-35, c-Jun N-terminal kinase (JNK) inhibitor or activator or dimethylsulfoxide (DMSO) as vehicle control, respectively. The mechanical allodynia was assayed to evaluate the therapeutic effect of IL-35. In mechanism study, the serum and protein levels of inflammatory cytokines using ELISA and western blotting and the activation of JNK signaling were further evaluated by quantitative reverse transcription PCR (qRT-PCR). Histopathologic changes were evaluated by Nissl staining. Apoptosis was examined using TUNEL staining.

Results

DNP rats exhibited increased fasting blood glucose and insulin levels and reduced insulin sensitivity index (ISI). Intrathecal injection of IL-35 reduced accumulation of pro-inflammatory cytokines in the spinal cord of DNP rats. Furthermore, IL-35 displayed anti-inflammatory and anti-apoptotic effects via inhibition of JNK pathway.

Conclusion

IL-35 treatment mitigated DNP via downregulating JNK signaling pathway.

Interleukin-35 suppresses antitumor activity of circulating CD8+ T cells in osteosarcoma patients

Purpose/Aim of the study: Interleukin (IL)-35 is a newly identified IL-12 cytokine family member and reveals immunosuppressive activity to CD8⁺ T cells in inflammation, infectious diseases, and cancers. However, little is known regarding IL-35 function in osteosarcoma. Thus, the aim of the current study was to investigate the regulatory function of IL-35 to CD8+ T cells in osteosarcoma. Materials and methods: Thirty-five osteosarcoma patients and 20 healthy individuals were enrolled. Serum CD4⁺CD25⁺CD127^dim/- regulatory T cells (Tregs) and CD8⁺ T cells were purified. IL-35 concentration in serum and cultured supernatants was measured by enzyme-linked immunosorbent assay. Osteosarcoma cell line MG-63 cells and CD8⁺ T cells were stimulated with recombinant IL-35 in vitro, and modulatory function of IL-35 on these cells was assessed by investigation of cellular proliferation, cell cycle, apoptosis, and cytokine production. Results: Serum IL-35 and Treg-secreting IL-35 were significantly elevated in osteosarcoma patients. IL-35 stimulation did not affect proliferation, apoptosis, or cell cycle of MG-63 cells. Purified peripheral CD8⁺ T cells from osteosarcoma patients revealed dysfunctional property, which presented as decreased mRNA expressions for perforin, granzyme B, and granulysin, as well as reduced cytolytic (direct lysis of target MG-63 cells) and noncytolytic (interferon-γ and tumor necrosis factor-α production) function in coculture systems. Moreover, IL-35 stimulation further diminished cytolytic and noncytolytic activity of CD8⁺ T cells from osteosarcoma patients. Conclusions: The current data indicated that IL-35 contributed to CD8⁺ T-cell dysfunction and limited antitumor immune response in osteosarcoma.

Interleukin-35 in immune-related diseases: protection or destruction

Interleukin-35 (IL-35) is a recently identified heterodimeric cytokine in the IL-12 family. It consists of an IL-12 subunit α chain (P35) and IL-27 subunit Epstein-Barr virus-induced gene 3 (EBI3) β chain. Unlike the other IL-12 family members, it signals through four unconventional receptors: IL-12Rβ2-IL-27Rα, IL-12Rβ2-IL-12Rβ2, IL-12Rβ2-GP130, and GP130-GP130. Interleukin-35 signaling is mainly carried out through the signal transducer and activator of transcription family of proteins. It is secreted not only by regulatory T (Treg) cells, but also by CD8+ Treg cells, activated dendritic cells and regulatory B cells. It exhibits immunosuppressive functions distinct from those of other members of the IL-12 family; these are mediated primarily by the inhibition of T helper type 17 cell differentiation and promotion of Treg cell proliferation. Interleukin-35 plays a critical role in several immune-associated diseases, such as autoimmune diseases and viral and bacterial infections, as well as in tumors. In this review, we summarize the structure and function of IL-35, describe its role in immune-related disorders, and discuss the mechanisms by which it regulates the development and progression of diseases, including inflammatory bowel disease, collagen-induced arthritis, allergic airway disease, hepatitis, and tumors. The recent research on IL-35, combined with improved techniques of studying receptors and signal transduction pathways, allows for consideration of IL-35 as a novel immunotherapy target.

Th lymphocyte subsets in patients with Vogt-Koyanagi-Harada disease

AIM

To assess helper T (Th) lymphocyte subset balance in patients with Vogt-Koyanagi-Harada (VKH) disease.

METHODS

Sixty-eight active VKH patients and seventy-two inactive VKH patients were included in this study. One hundred healthy individuals served as controls. Peripheral blood was obtained from VKH patients and healthy controls. Th lymphocyte subsets were analyzed by flow cytometry. Plasma concentration of interleukin (IL)-17, IL-10, transforming growth factor (TGF)-β, IL-23 and IL-6 was examined by enzyme-linked immunosorbent assay (ELISA).

RESULTS

VKH patients with active uveitis had significantly higher percentages of both Th1 and Th17 cells and lower percentages of regulatory T (Treg) cells as compared with inactive VKH patients and healthy controls. Th1/Th2 and Th17/Treg ratios were also significantly elevated in active VKH patients. The percentages of Th1, Th17 and Treg cells and the Th1/Th2, Th17/Treg ratio did not differ between inactive VKH patients and healthy controls. There was no difference concerning the percentage of Th2 cells among all the groups. VKH patients with active uveitis showed an elevated level of peripheral Th17 related cytokines levels (TGF-β, IL-6, IL-23, and IL-17) and a decreased level of Treg related cytokines (IL-10) compared with inactive VKH patients and healthy controls. Inactive VKH patients showed no differences in peripheral Th17 related cytokines (TGF-β, IL-6, IL-23, and IL-17) and Treg related cytokines (IL-10) levels compared with healthy controls.

CONCLUSION

Th1 and Th17 cells are significantly increased and Treg cells significantly decreased in active VKH compared with inactive VKH or healthy controls. Therefore, Th lymphocyte subset analysis may serve as a disease biomarker for VKH.

Delivery of IL-35 by Lactococcus lactis Ameliorates Collagen-Induced Arthritis in Mice

IL-35, a relatively newly discovered cytokine belonging to the larger IL-12 family, shows unique anti-inflammatory properties, believed to be associated with dedicated receptors and signaling pathways. IL-35 plays a pivotal role in the development and the function of both regulatory B (Bregs) and T cells (Tregs). In order to further its therapeutic potential, a dairy Lactococcus lactis strain was engineered to express murine IL-35 (LL-IL35), and this recombinant strain was applied to suppress collagen-induced arthritis (CIA). Oral administration of LL-IL35 effectively reduced the incidence and disease severity of CIA. When administered therapeutically, LL-IL35 abruptly halted CIA progression with no increase in disease severity by reducing neutrophil influx into the joints. LL-IL35 treatment reduced IFN-γ and IL-17 3.7- and 8.5-fold, respectively, and increased IL-10 production compared to diseased mice. Foxp3+ and Foxp3- CD39+ CD4+ T cells were previously shown to be the Tregs responsible for conferring protection against CIA. Inquiry into their induction revealed that both CCR6+ and CCR6- Foxp3+or- CD39+ CD4+ T cells act as the source of the IL-10 induced by LL-IL35. Thus, this study demonstrates the feasibility and benefits of engineered probiotics for treating autoimmune diseases.

Interleukin 35 induced Th2 and Tregs bias under normal conditions in mice

Objective

The benefits of IL-35 treatment have been verified in multiple animal models of diseases, while its influence on T cells immunity under normal condition still needs to be elucidated. The present study was designed to investigate the effects modulating IL-35 levels in vivo and in vitro on T cells, response and also the effects on T cells subsets in normal mice.

Methods

A plasmid pMSCV-IL-35-GFP carrying mouse linear IL-35 fragment with two subunits joint together was constructed and the heterodimer expression was confirmed. Normal mice were randomly divided into three groups and received an intravenous injection of PBS, pMSCV-GFP and pMSCV-IL-35-GFP respectively. After 72 h, spleen tissues and peripheral blood were harvested for following analysis. Meanwhile, splenic T cells were isolated and incubated with 10, 30, or 50 ng/mL recombinant IL-35 factor for 24 h with the addition of anti-CD3/CD28 in vitro. T-cell subsets were assessed by Fluorescence activated cell sorting (FACS) and related cytokines together with effector molecules were determined by real time PCR.

Results

Western blotting confirmed a 52 kDa band in the cell lysate of HEK 293T transducted with pMSCV-IL-35-GFP plasmid, indicating a successful expression of IL-35. Ebi3 and IL-12A, two subunits of IL-35, could be identified 72 h post DNA injection. IL-35 upregulation in vivo effectively inhibit CD4⁺ and CD8⁺ T cell proliferation and Th1 cytokine secretion. Effector molecules of CD8⁺ T cells were also remarkably suppressed. On the contrary, high level of IL-35 significantly induced CD4⁺ CD25⁺ Tregs and Th2 enhancement. The in vitro study provided similar results.

Conclusion

The results indicated Th1 and CD8⁺ T cell inhibition and Th2 and Tregs bias in the presence of IL-35 under a normal state which partly contributed to its therapeutic potential.

Interleukin-35 Attenuates D-Galactosamine/Lipopolysaccharide-Induced Liver Injury via Enhancing Interleukin-10 Production in Kupffer Cells

Interleukin (IL) -35 is an anti-inflammatory cytokine which exerts various beneficial effects on autoimmune diseases. However, whether IL-35 plays a role in endotoxin induced hepatitis demands clarification. This study aims to reveal the effect and mechanism of IL-35 on endotoxin induced liver injury. Acute hepatic injury was induced by D-galactosamine (D-GalN, 400 mg/kg) and lipopolysaccharide (LPS, 5 μg/kg) administration in mice. IL-35 treatment ameliorated D-GalN/LPS induced liver injury in a dose dependent manner as shown by histological examination, ALT determination and Caspase-3 activity assay. It also reduced production of pro-inflammatory cytokines, tumor necrosis factor (TNF)-α, IL-1β, and IL-6, and increased production of anti-inflammatory cytokines, IL-4, IL-10, and transforming growth factor (TGF)-β. This hepato-protective effect was proved mainly mediated by Kupffer cells (KC) via gadolinium chloride depletion and cell adoptive transfer experiment. In addition, IL-35 emolliated the cytotoxicity of LPS-triggered KCs to hepatocytes, suppressed nitric oxide (NO) and TNF-α production, and elevated IL-10 production in LPS stimulated KCs. Furthermore, IL-35 could not exert hepato-protective effect in IL-10-deficient mice in vivo and it could not suppress LPS induced NO and TNF-α production in IL-10-deficient KCs in vitro. In conclusion, IL-35 protects endotoxin-induced acute liver injury, which mainly acts thought increasing IL-10 production in KCs. This finding demonstrates a role of IL-35 in anti-infectious immunity and provides a potential therapeutic target in treating fulminant hepatitis.