Decreased IL-35 levels in patients with immune thrombocytopenia

Decreased Expression of IL-35 and Its Receptor Contributes to Impaired Megakaryopoiesis in the Pathogenesis of Immune Thrombocytopenia

Recent findings have shown that the level of interleukin-35 (IL-35) is abnormal in several autoimmune diseases. Nonetheless, whether IL-35 participates in the pathogenesis of immune thrombocytopenia (ITP) remains unclear. The current study investigates whether IL-35 modulates megakaryopoiesis. The results show that IL-35 receptors are progressively expressed on bone marrow megakaryocytes during the in vitro differentiation of CD34+ progenitors. IL-35 increases the number of megakaryocyte colony-forming units through the Akt pathway. The level of bone marrow IL-35 is reduced in ITP patients, and the decreased level of IL-35 may inhibit megakaryopoiesis. Then, the potential causes of decreased IL-35 in ITP patients are explored. The primary type of cell that secretes IL-35, known as IL-35-producing regulatory T cells (iTr35), is reduced in ITP patients. Bone marrow mesenchymal stem cells (MSCs) from ITP patients exhibit an impaired capability of inducing iTr35 due to enhanced apoptosis, which may contribute to the reduced level of bone marrow IL-35 in ITP patients. Iguratimod promotes megakaryocyte development and differentiation by elevating the expression of IL-35 receptors on megakaryocytes. Iguratimod improves response rates and reduces bleeding symptoms in corticosteroid-resistant ITP patients.

Immunomodulation with romiplostim as a second-line strategy in primary immune thrombocytopenia: The iROM study

Thrombopoietin receptor agonists (TPO-RAs) stimulate platelet production, which might restore immunological tolerance in primary immune thrombocytopenia (ITP). The iROM study investigated romiplostim's immunomodulatory effects. Thirteen patients (median age, 31 years) who previously received first-line treatment received romiplostim for 22 weeks, followed by monitoring until week 52. In addition to immunological data, secondary end-points included the sustained remission off-treatment (SROT) rate at 1 year, romiplostim dose, platelet count and bleedings. Scheduled discontinuation of romiplostim and SROT were achieved in six patients with newly diagnosed ITP, whereas the remaining seven patients relapsed. Romiplostim dose titration was lower and platelet count response was stronger in patients with SROT than in relapsed patients. In all patients, regulatory T lymphocyte (Treg) counts increased until study completion and the counts were higher in patients with SROT. Interleukin (IL)-4, IL-9 and IL-17F levels decreased significantly in all patients. FOXP3 (Treg), GATA3 (Th2) mRNA expression and transforming growth factor-β levels increased in patients with SROT. Treatment with romiplostim modulates the immune system and possibly influences ITP prognosis. A rapid increase in platelet counts is likely important for inducing immune tolerance. Better outcomes might be achieved at an early stage of autoimmunity, but clinical studies are needed for confirmation.

Urine and serum interleukin 35 as potential biomarkers of lupus nephritis

Introduction

Lupus nephritis (LN) is considered a serious manifestation of systemic lupus erythematosus (SLE). Therefore, a reliable non-invasive biomarker is a priority for monitoring renal involvement instead of the kidney biopsy. Interleukin 35 (IL-35) has an immunosuppressive and anti-inflammatory role in many autoimmune diseases. However, its role in LN still needs to be elucidated.

Aim of the study

To evaluate urine and serum levels of IL-35 in SLE patients with LN and without nephritis identifying their potential as biomarkers of renal involvement.

Material and methods

Urine and serum levels of IL-35 were measured in 42 SLE patients, divided into 22 with LN and 20 without LN, and 20 matched healthy controls using enzyme-linked immunosorbent assay (ELISA). SLE disease activity was assessed for patients by the Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K).

Results

Levels of serum and urine IL-35 were significantly higher (p < 0.001) in the LN group compared with those without LN and with controls. In LN patients, a strong correlation (p < 0.001) was observed between serum and urine IL-35 levels with SLEDAI-2K score (r = 0.677 and 0.806 respectively). Furthermore, proteinuria had a strong and significant correlation (p ˂ 0.001) with serum and urinary IL-35 levels in the patients with LN. Serum IL-35 had 90.9% sensitivity and 85% specificity while urine IL-35 had 95.5% sensitivity and 75% specificity to differentiate LN from healthy individuals.

Conclusions

Urine and serum IL-35 may aid in assessment of renal involvement in SLE patients, serving as potential biomarkers of LN.

Decreased levels of immune-regulatory cytokines in patients with immune thrombocytopenia and long-lasting overexpression of these cytokines in the splenectomized patients

Immune thrombocytopenia (ITP) is an autoimmune-mediated disease characterized by decreased platelet counts. Cytokines play important roles in modulating the immune response and are involved in the pathogenesis of many autoimmune diseases. This study aimed at exploring the serum levels of a core set of cytokines that exert immune-regulatory functions in newly diagnosed ITP patients (both before and after treatment) and splenectomized ITP patients. Using the Bio-Plex suspension array system and ELISA, the serum levels of IL-10, IL-21, IL-27, IL-33, IL-35, IL-37, and TGF-β₁ were detected. The data showed that the serum levels of the immune regulatory cytokines IL-10, IL-35, and TGF-β₁ were significantly lower in newly diagnosed ITP patients. Decreased cytokine levels could be improved in patients with a complete response or a response after steroid-based treatment(s). The serum concentrations of TGF-β₁ were positively correlated with the platelet counts both before and after treatment. All the detected immune-regulatory cytokines, except IL-37, showed significantly higher levels in splenectomized ITP patients than pretreatment ITP patients and healthy controls. In conclusion, these data suggest that lower levels of immune-regulatory cytokines are involved in the pathogenesis of ITP and that there is a long-lasting overexpression of immune-regulatory cytokines in ITP patients with splenectomy.

Reduced IL-35 in patients with immune thrombocytopenia

: The occurrence and development of primary immune thrombocytopenia is closely related to autoimmune imbalanced. Thus, we conducted the current study to investigate the modulation of IL-35, a newly identified immunological self-tolerance factor on immune thrombocytopenic purpura (ITP). We were enrolled peripheral blood in 21 adult healthy volunteers, 21 active primary ITP patients and 16 ITP patients in remission. In the same period, bone marrow plasma was drawn from active primary ITP patients and 16 bone marrow donors. Enzyme-linked immunoassay was used to measure IL-35 levels in bone marrow mononuclear cells and peripheral blood mononuclear cells. Real-time quantitative PCR was used to study the mRNA expression levels of p35, Epstein-Barr virus-induced gene 3 in bone marrow mononuclear cells and peripheral blood mononuclear cells. Compared with the normal group, IL-35 levels of in ITP patients were decreased significantly. IL-35 level in bone marrow plasma was decreased more significantly than that in peripheral blood plasma at the same stage. The results showed that plasma IL-35 levels were significantly decreased in patients with active ITP compared with those of control individuals, and IL-35 levels in bone marrow plasma were decreased more significantly compared with those at the same stage. The pathogenesis of ITP is associated with decreased IL-35 levels. Further studies are needed to expand sample content and explore more in-depth investigate a possible role of IL-35 in the pathogenesis and course of ITP.

Immunomodulatory cytokine interleukin-35 and immune thrombocytopaenia

Considerable attention has been paid to interleukin (IL)-35 because of its immunosuppressive effects in a variety of autoimmune diseases. IL-35, a recently identified cytokine of the IL-12 family, is a negative regulatory factor secreted by IL-35-inducible regulatory T cells (iTr35 cells) and the recently reported regulatory B cells (Breg cells). Four biological effects of IL-35 have been discovered in vitro and in vivo: (i) suppression of T cell proliferation; (ii) conversion of naive T cells into iTr35 cells; (iii) downregulation of type 17 helper T (Th17) cells; and (iv) conversion of Breg cells into a Breg subset that produces IL-35 and IL-10. IL-35 plays an important role in a variety of autoimmune diseases, such as rheumatoid arthritis, allergic asthma and systemic lupus erythematosus. Primary immune thrombocytopaenia (ITP), which is characterized by isolated thrombocytopaenia and mild mucocutaneous to life-threatening bleeding, is an autoimmune disease with complex dysregulation of the immune system. Both antibody-mediated and/or T cell-mediated platelet destruction are key processes. In addition, impairment of T cells and cytokine imbalances have now been recognized to be important. This review summarizes the immunomodulatory effects of IL-35 and its role in the pathogenesis of ITP as mediated by T and B cells.

Association between Interleukin 35 Gene Single Nucleotide Polymorphisms and Systemic Lupus Erythematosus in a Chinese Han Population

Interleukin-35 (IL-35) exerts crucial roles in the pathogenesis and development of systemic lupus erythematosus (SLE), in this study we aim to explore the associations between IL-35 gene polymorphisms and the susceptibility, clinical features and plasma IL-35 levels of SLE patients, respectively. 490 SLE patients and 489 healthy controls were recruited in our study. The correlations between the polymorphisms of seven SNPs of IL-35 encoding gene and the susceptibility, main clinical manifestations of SLE were evaluated, respectively. Plasma IL-35 levels were assessed in 76 SLE patients, and the associations between plasma IL-35 levels and the polymorphisms of genotyped SNPs were explored. There were significant associations between the polymorphisms of rs4740 and the occurrence of renal disorder, hematological disorder in SLE patients, respectively (p = 0.001; p = 0.001). In addition, there were no significant associations observed between the genotype frequencies of genotyped SNPs and the risk of SLE, plasma IL-35 levels, respectively. The polymorphism of rs4740 of IL-35 encoding gene is associated with the occurrence of renal disorder and hematological disorder of SLE patients.

Serum interleukin-35 and pentraxin-3 levels in patients with mild acute pancreatitis

Introduction

Interleukin-35 (IL-35) is a newly defined potent anti-inflammatory cytokine that is predominantly produced by regulatory T cells, and pentraxin-3 belongs to the acute-phase proteins.

Aim

To measure the serum IL-35 and pentraxin-3 levels in the early phase of mild acute pancreatitis (AP).

Material and methods

Eighty-three patients with mild AP and 30 healthy controls were included in the study. The serum levels of IL-35 and pentraxin-3 were measured by enzyme-linked immunosorbent assay upon admission and at the 48^th hour after diagnosis.

Results

The mean value of serum IL-35 levels in patients with mild acute pancreatitis at admission was 5.91 ng/ml (4.21–7.90) and was significantly lower than those in healthy controls (25.53 ng/ml (12.79–54.73, p < 0.001)) and 48-hour value were (6.79 ng/ml (4.42–9.62) (p = 0.015)). The mean value of serum pentraxin-3 levels in patients at the time of admission was 6.75 ng/ml (4.42–9.62) and there was no significant difference from healthy controls, at 7.64 ng/ml (6.58–8.62, p > 0.05). Also there was no significant difference between the mean value at admission and the mean value at 48-hour, 6.75 ng/ml (4.74–9.06, p > 0.05).

Conclusions

Interleukin-35 can be used in diagnosis and follow-up in patients with mild AP.

Aberrant IL-35 levels in patients with primary Sjogren's syndrome

OBJECTIVE

IL-35 is a newly discovered immunoregulatory cytokine that possesses the ability to inhibit CD4 + effector T cells and alleviate autoimmune diseases. The objective of this study was to investigate IL-35 levels in patients with primary Sjogren's syndrome (pSS) and explore the roles of IL-35 in the pathogenesis of pSS.

METHODS

Thirty-four hospitalized patients with pSS were recruited, and 34 volunteers were enrolled as healthy controls. An ELISA was adopted to measure plasma IL-35 levels. The levels of P35 and EBI3 mRNAs in peripheral blood mononuclear cells (PBMCs) were determined using real-time quantitative PCR. The percentage of CD4 + EBI3 + T cells and CD19 + EBI3 + B cells was analysed using flow cytometry. Correlations between IL-35 levels, P35 and EBI3 mRNAs, numbers of CD4 + EBI3 + T cells, CD19 + EBI3 + B cells and clinical parameters were analysed.

RESULTS

Significantly lower plasma IL-35 levels, P35 and EBI3 mRNA levels, and percentages of CD4 + EBI3 + T cells but increased percentages of CD19 + EBI3 + B cells were observed in patients with pSS than in healthy controls. IL-35 levels, EBI3 mRNA expression and the percentage of CD4 + EBI3 + T cells exhibited negative correlations with the ESSDAI score, whereas levels of the IL-35 protein and EBI3 mRNA were negatively correlated with the ESR. Patients who were positive for anti-SSB antibodies presented with lower IL-35 levels and percentages of CD4 + EBI3 + T cells.

CONCLUSIONS

Based on these results, a decrease in the IL-35 levels may play an important role in the pathogenesis of pSS. IL-35 may act as a potential therapeutic agent against inflammation in patients with pSS.

Diminished circulating concentration of interleukin-35 in Helicobacter pylori-infected patients with peptic ulcer: Its association with FOXP3 gene polymorphism, bacterial virulence factor CagA, and gender of patients

BACKGROUND

IL-35 modulates immune and inflammatory responses during infections. Here, we investigated IL-35 levels and a single nucleotide polymorphism, rs3761548, in FOXP3 gene in Helicobacter pylori-infected patients with peptic ulcer (PU), to clarify possible associations.

MATERIALS AND METHODS

This study includes 100 H. pylori-infected PU patients, 100 H. pylori-infected asymptomatic subjects (AS), and 100 noninfected healthy subjects (NHSs). Serum IL-35 levels and the genotyping were determined using ELISA and RFLP-PCR methods, respectively.

RESULTS

In PU patients, the IL-35 levels were lower than AS and NHS groups (P < .001). The IL-35 levels in CagA⁺ H. pylori-infected participants from PU and AS groups were lower than individuals infected with CagA^- strains (P < .02 and P < .04, respectively). Women had higher IL-35 levels than men among PU, AS, and NHS groups (P < .0001). In PU patients, AA genotype and A allele at rs3761548 were more frequent than total healthy subjects (AS + NHS groups) and associated with an increased PU risk (AA genotype: OR = 5.51, P < .0001; A allele: OR = 3.857, P < .002). In PU and AS groups, IL-35 levels were lower in subjects displaying AA genotype or A allele than subjects displaying CC genotype or C allele, respectively (P < .0001 and P < .03 for PU patients; P < .001 and P < .02 for AS group, respectively).

CONCLUSIONS

Decreased IL-35 levels could be involved in PU development in H. pylori-infected individuals. IL-35 levels are affected by CagA status of H. pylori, participants gender, and genetic variations at rs3761548. The AA genotype and A allele at rs3761548 could represent a risk factor for PU development.

Clinical Significance of Decreased Interleukin-35 Expression in Patients with Psoriasis

In psoriasis, a chronic, recurrent, inflammatory skin disease, CD4+T cells and their related cytokines play an important role in its pathogenesis. The role of interleukin (IL)-35, an immunosuppressive cytokine involved in many autoimmune diseases, is unclear in the pathogenesis of psoriasis. This study evaluated IL-35 expression and clinical significance in psoriasis. Protein and mRNA levels of specified markers were measured by enzyme-linked immunosorbent assay (ELISA) and real-time quantitative polymerase chain reaction (qRT-PCR), respectively. Results showed that plasma IL-35 concentrations were lower in patients with psoriasis than in healthy individuals (Z = -6.525, P < .0001). Ebi3 and p35 showed lower mRNA levels in peripheral blood mononuclear cells from patients with psoriasis than in healthy individuals (Z = -5.078, P < .0001, Z = -2.609, P = .009, respectively). The areas under the receiver-operating characteristic (ROC) curves of IL-35, Ebi3, and p35 for patients with psoriasis versus the control were 0.86, 0.78, and 0.64, respectively. Pearson correlation analysis showed that plasma IL-35 expression negatively correlated with interferon-gamma, tumor necrosis factor-alpha, levels of IL-23, -17, and -22, or the Psoriasis Activity and Severity Index and positively correlated with levels of transforming growth factor beta and IL-10 levels in patients with psoriasis. Summarily, IL-35 might mediate psoriasis pathogenesis by influencing the expression of Th1/Th17/Treg -related cytokines and might be a putative target in monitoring or treating psoriasis.

Role of the IL-12/IL-35 balance in patients with Sjögren syndrome

BACKGROUND

An interferon signature is involved in the pathogenesis of primary Sjögren syndrome (pSS), but whether the signature is type 1 or type 2 remains controversial. Mouse models and genetic studies suggest the involvement of T_H1 and type 2 interferon pathways. Likewise, polymorphisms of the IL-12A gene (IL12A), which encodes for IL-12p35, have been associated with pSS. The IL-12p35 subunit is shared by 2 heterodimers: IL-12 and IL-35.

OBJECTIVE

We sought to confirm genetic association of the IL12A polymorphism and pSS and elucidate involvement of the IL-12/IL-35 balance in patients with pSS by using functional studies.

METHODS

The genetic study involved 673 patients with pSS from 2 French pSS cohorts and 585 healthy French control subjects. Functional studies were performed on sorted monocytes, irrespective of whether they were stimulated. IL12A mRNA expression and IL-12 and IL-35 protein levels were assessed by using quantitative RT-PCR and ELISA and a multiplex kit for IL-35 and IL-12, respectively.

RESULTS

We confirmed association of the IL12A rs485497 polymorphism and pSS and found an increased serum protein level of IL-12p70 in patients with pSS carrying the risk allele (P = .016). Serum levels of IL-12p70 were greater in patients than control subjects (P = .0001), especially in patients with more active disease (P = .05); conversely, IL-35 levels were decreased in patients (P = .0001), especially in patients with more active disease (P = .05). In blood cellular subsets both IL12p35 and EBV-induced gene protein 3 (EBI3) mRNAs were detected only in B cells, with a trend toward a lower level among patients with pSS.

CONCLUSION

Our findings emphasize involvement of the IL-12/IL-35 balance in the pathogenesis of pSS. Serum IL-35 levels were associated with low disease activity, in contrast with serum IL-12p70 levels, which were associated with more active disease.

Interleukin-35: a Potential Therapeutic Agent for Autoimmune Diseases

Autoimmune diseases contain a large number of pathologies characterized by various factors that contribute to a breakdown in self-tolerance. Cytokine-mediated immunity plays an essential role in the pathogenesis of varieties of autoimmune diseases. Recent studies reveal that interleukin-35 (IL-35), a newly identified cytokine of IL-12 family, is implicated in the pathogenesis of autoimmune diseases, such as systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), systemic sclerosis (SSc), etc. In this review, we will discuss the biological features of IL-35 and summarize recent advances in the role of IL-35 in the development and pathogenesis of autoimmune diseases; the discoveries gained from these findings might translate into future therapies for these diseases.

Interleukin-35 administration counteracts established murine type 1 diabetes--possible involvement of regulatory T cells

The anti-inflammatory cytokine IL-35 is produced by regulatory T (Treg) cells to suppress autoimmune and inflammatory responses. The role of IL-35 in type 1 diabetes (T1D) remains to be answered. To elucidate this, we investigated the kinetics of Treg cell response in the multiple low dose streptozotocin induced (MLDSTZ) T1D model and measured the levels of IL-35 in human T1D patients. We found that Treg cells were increased in MLDSTZ mice. However, the Treg cells showed a decreased production of anti-inflammatory (IL-10, IL-35, TGF-β) and increased pro-inflammatory (IFN-γ, IL-2, IL-17) cytokines, indicating a phenotypic shift of Treg cells under T1D condition. IL-35 administration effectively both prevented development of, and counteracted established MLDSTZ T1D, seemingly by induction of Eos expression and IL-35 production in Treg cells, thus reversing the phenotypic shift of the Treg cells. IL-35 administration reversed established hyperglycemia in NOD mouse model of T1D. Moreover, circulating IL-35 levels were decreased in human T1D patients compared to healthy controls. These findings suggest that insufficient IL-35 levels play a pivotal role in the development of T1D and that treatment with IL-35 should be investigated in treatment of T1D and other autoimmune diseases.

Interleukin-35: Expanding Its Job Profile

Counter-regulation afforded by specialized regulatory cell populations and immunosuppressive cytokines is critical for balancing immune outcome. The inhibitory potential of the established suppressive cytokines, IL-10 and TGFβ, has been well elucidated in diverse inflammatory scenarios in conjunction with their key roles in Treg development and function. Despite the early predictions for an immunomodulatory role for the Ebi3/p35 heterodimer in placental trophoblasts, IL-35 biology remained elusive until 2007 when it was established as a Treg-restricted inhibitory cytokine. Since then, Treg-derived IL-35 has been shown to exhibit its suppressive activities in a range of autoimmune diseases and cancer models. Recent studies are beginning to explore other cellular sources of IL-35, such as Bregs and CD8(+) Tregs. Despite these new cellular sources and targets, the mode of IL-35 suppression remains restricted to inhibition of proliferation and induction of an IL-35-producing induced regulatory T cell population referred to as iTr35. In this review, we explore the early beginnings, status quo, and future prospects of IL-35 biology. The unparalleled opportunity of targeting multiple immunosuppressive populations (Tregs, Bregs, CD8(+) Tregs) through IL-35 is highly exciting and offers tremendous promise from a translational standpoint, particularly for cancer immunotherapies.

Interleukin 35 may contribute to the loss of immunological self-tolerance in patients with primary immune thrombocytopenia

Primary immune thrombocytopenia (ITP) is an autoimmune disorder. Interleukin-35 (IL35) can suppress T cell proliferation and elicit the development of inducible regulatory T cells (Tregs). Previous studies have shown decreased plasma IL35 levels and dysfunctional T cells in patients with ITP. In this study, we determined whether decreased IL35 levels correlate with T cell dysfunction in ITP patients. Plasma IL35 levels were found to be lower in ITP patients than in healthy controls, were positively correlated with platelet levels and the percentage of peripheral circulating Tregs, and negatively correlated with the levels of T helper-1 cells in ITP patients. We also evaluated the effects of IL35 on cytokines contributing to T cell proliferation. IL35 promoted the secretion of interleukin 10 (IL10) and transforming growth factor-β1 but reduced the levels of interferon-γ and IL17A (also termed IL17). Moreover, IL35 inhibited the proliferation of CD4+ and CD8+ T cells but induced the differentiation and proliferation of Tregs in ITP. In summary, IL35 appears to contribute to the loss of immunological self-tolerance in ITP patients by modulating T cells and immunoregulatory cytokines.