Interleukin-35 is a critical regulator of immunity during helminth infections associated with multiple sclerosis.

Multiple sclerosis (MS) is currently thought to arise by interactions between genetic susceptibility and environmental factors. Infections in general trigger autoimmune responses causing clinical manifestations of disease. However, as a result of regulatory T (Treg)- and regulatory B (Breg)-cell induction, helminth infections tend to dampen disease activity. IL-35, the newest member of the IL-12 family, is an inhibitory cytokine composed of an EBI3ß chain subunit, and an IL-12p35 subunit. The aim of this study was to investigate the role of IL-35 during parasite infections occurring in individuals with MS. Numbers of IL-35-producing Breg cells are higher in CSF from helminth-infected than from uninfected MS subjects, a finding associated with decreased MRI disease activity. Interestingly, stimulation of CD19+ B cells with IL-35 promotes conversion of these cells to Breg cells producing both IL-35 and IL-10. Coculture of B cells from helminth-infected MS patients inhibits proliferation of Th1 and Th17 myelin peptide-specific T cells, as well as production of IFN-γ and IL-17. Following activation, CD4+ CD25+ Treg cells significantly upregulate expression of EBI3 and IL-12p35 mRNA. Furthermore, CD4+ CD25- T cells activated in the presence of IL-35 induce a population of cells with regulatory function, known as iTR35. Finally, B cells from normal individuals cultured in vitro in the presence of the helminth antigen SEA increase expression of the transcription BATF, IRF4 and IRF8, acquiring a pattern similar to that of IL-35 Breg cells. These data highlight the important immunoregulatory effects of IL-35 on both Breg and Treg cells, observed in helminth-infected MS subjects.

Immunosuppressive Mechanisms of Regulatory B Cells.

Regulatory B cells (Bregs) is a term that encompasses all B cells that act to suppress immune responses. Bregs contribute to the maintenance of tolerance, limiting ongoing immune responses and reestablishing immune homeostasis. The important role of Bregs in restraining the pathology associated with exacerbated inflammatory responses in autoimmunity and graft rejection has been consistently demonstrated, while more recent studies have suggested a role for this population in other immune-related conditions, such as infections, allergy, cancer, and chronic metabolic diseases. Initial studies identified IL-10 as the hallmark of Breg function; nevertheless, the past decade has seen the discovery of other molecules utilized by human and murine B cells to regulate immune responses. This new arsenal includes other anti-inflammatory cytokines such IL-35 and TGF-ß, as well as cell surface proteins like CD1d and PD-L1. In this review, we examine the main suppressive mechanisms employed by these novel Breg populations. We also discuss recent evidence that helps to unravel previously unknown aspects of the phenotype, development, activation, and function of IL-10-producing Bregs, incorporating an overview on those questions that remain obscure.

Decreased serum levels of IL-27and IL-35 in patients with Graves disease.

OBJECTIVE: Graves' disease (GD) is an autoimmune disease causing the overproduction of the thyroid hormone from thyroid gland. This disease is mainly the result of the production of antibodies against TSH receptors. Cytokines play an important role in orchestrating the pathophysiology in autoimmune thyroid disease. The regulatory role of IL-12 on TH1 cells has been proven. IL-27 and IL-35, members of IL-12 cytokine family, are two cytokines that have been newly discovered. IL-35 has been identified as a novel immunosuppressive and anti-inflammatory cytokine while IL-27 has both inflammatory and anti-inflammatory functions. The objective of the current study was to examine the changes in the serum level of the foregoing cytokines in GD patients in comparison to healthy controls. METHODS: In this study, serum levels of IL-27 and IL-35 were determined by an ELISA method; anti TPO and anti Tg were measured by an RIA method in 40 new cases of Graves's disease. The findings were compared with 40 healthy controls. RESULTS: The results showed a significant difference between IL-27 and IL-35 regarding their serum levels with P values of 0.0001 and 0.024, respectively; anti TPO and anti Tg levels of the cases were also significantly different from controls (p < 0.001). CONCLUSION: The reduction in the serum levels of IL-27 and IL-35 in GD patients compared to normal subjects suggests the possible anti-inflammatory role of these cytokines in GD.

Decreased serum levels of IL-27and IL-35 in patients with Graves disease

ABSTRACT Objectives Graves' disease (GD) is an autoimmune disease causing the overproduction of the thyroid hormone from thyroid gland. This disease is mainly the result of the production of antibodies against TSH receptors. Cytokines play an important role in orchestrating the pathophysiology in autoimmune thyroid disease. The regulatory role of IL-12 on TH1 cells has been proven. IL-27 and IL-35, members of IL-12 cytokine family, are two cytokines that have been newly discovered. IL-35 has been identified as a novel immunosuppressive and anti-inflammatory cytokine while IL-27 has both inflammatory and anti-inflammatory functions. The objective of the current study was to examine the changes in the serum level of the foregoing cytokines in GD patients in comparison to healthy controls. Materials and methods In this study, serum levels of IL-27 and IL-35 were determined by an ELISA method; anti TPO and anti Tg were measured by an RIA method in 40 new cases of Graves's disease. The findings were compared with 40 healthy controls. Results The results showed a significant difference between IL-27 and IL-35 regarding their serum levels with P values of 0.0001 and 0.024, respectively; anti TPO and anti Tg levels of the cases were also significantly different from controls (p < 0.001). Conclusion The reduction in the serum levels of IL-27 and IL-35 in GD patients compared to normal subjects suggests the possible anti-inflammatory role of these cytokines in GD.

Interleukin 35 (IL-35) and IL-37: Intestinal and peripheral expression by T and B regulatory cells in patients with Inflammatory Bowel Disease.

The aim of the study was to characterize and to quantify peripheral and tissue. IL-35- and IL-37-producing cells in Inflammatory Bowel Disease (IBD) patients. We studied a total of 38 active UC, 31 inactive UC, 17 active CD, and 13 inactive CD and 50 non-inflamed tissues as control group. Gene expression was measured by real time polymerase chain reaction (RT-PCR) and protein expression was evaluated in tissue by immunohistochemistry and in peripheral blood mononuclear cells by flow cytometry. Higher levels of IL-35 was produced by intestinal regulatory B cells and circulating regulatory CD4(+) and CD8(+) T cells in active vs. inactive disease or healthy donors (P<0.05). The IL-37 was conspicuously synthesized by circulating B cells, active natural killer cells and monocytes. These results suggest that down-regulation of inflammation in active IBD patients might be based on the increased expression of IL-35 and IL-37.

Interleukin (IL)-35 is raising our expectations / Las expectativas futuras de la interleukina (IL)-35

Purpose: To elucidate and discuss the role of IL-35 in immunity to parasitic and bacterial infections as well as in autoimmunity in terms of its anti-infammatory properties, we highlight significant findings on this novel member of the IL-12 family. Methods: Studies using genetically defcient mice have greatly enhanced our understanding of the biology of IL-35. On the basis of data derived from the analysis of these genetically deficient mice published by NIH, we focus on the key features of this heterodimeric cytokine, especially its relation to the other IL-12 family members, and discuss its potential relevance to the clinical usage. Principal fndings: IL-35 is required for the CD4+CD25+ Treg cells-mediated immune regulation, the alleviation of some inflammatory responses, as well as the expansion of CD4+CD25- Teff cells simultaneously. Moreover, administration or augmentation of IL-35 suppresses some diseases of autoimmune or allergic origin like collagen-induced arthritis or Helicobacter- induced colitis in animal models, demonstrating its potential in therapy of diseases mediated by inflammatory cytokines. However, some questions involving it are still unclear, including the composition of IL-35 receptor, IL-35-related cell signaling pathway, the different expression patterns of IL-35 between human and murine T cells, etc. Conclusion: As our understanding of the IL-35 is rapidly growing and changing, it will bring us more therapeutic strategies towards some intractable immune diseases such as Lupus Erythematosus.

Esta es una revisión acerca del rol de IL-35, un nuevo miembro de la familia IL-12, en la respuesta inmunitaria contra infecciones parasitarias y bacterianas y de su rol benefcioso en reacciones auto inmunes, debido sus propiedades antiinfamatorias. Basándose en estudios de ratones genéticamente defcientes se ha determinado que se requiere IL-35 para la acción inmunoreguladora de las células T reguladoras CD4+CD25+, para mitigar algunos procesos inflamatorios y para expandir simultáneamente los clones de células T efectoras CD4+CD25-. Mas aún, la administración o estimulación de la acción de IL-35 en modelos animales, suprime algunas enfermedades de origen alérgico o autoinmune tales como la colitis colágena y la colitis inducida por Helicobacter. Estos experimentos demuestran el potencial terapéutico de IL-35 en enfermedades mediadas por citokinas inflamatorias. Sin embargo, algunos aspectos de la citokina aún no han sido dilucidados, tales como la composición del receptor de IL-35, la vía de señalización celular asociada a IL-35 y los diversos patrones de expresión de la citokina en células humanas y de ratones. En la medida que aumente el conocimiento acerca de las acciones de IL-35, nos podrá proveer tratamientos para algunas enfermedades auto inmunes actualmente limitadas en su tratamiento, como el lupus eritematoso.