IL-10 Pathway Research Articles

SP0029 Auto-Immune and Auto-Inflammatory Monogenic Diseases of the Immune System. What can be Learned from their Studies?

In the recent years, multiple monogenic diseases have been described that cause auto-inflammatory and/or auto-immune diseases in association or not with vulnerability to microorganisms i.e, classic primary immunodeficiencies. I would...

Targeting the IL-10 Pathway by RNA Interference Has Beneficial Effects on the Development of Experimental Lupus

Results from patients with systemic lupus erythematosus (SLE) and from mice suffering from a lupus-like disease suggest that the IL-10 pathway is involved in pathogenesis, and that this cytokine could represent a target for managing SLE development. In this study, we constructed JC virus-like particles (VLP) expressing IL-10-specific short hairpin RNAs (shRNAs) that efficiently silenced IL-10 gene expression. In mice, a single injection of this preparation dramatically reduced serum levels of ILIO. We tested the preventive effect of this vector expressing anti-IL-10 shRNAs in female (NZBxNZW) F, mice. Weekly intraperitoneal injections decreased the incidence and severity of proteinuria, and prolonged lifespan, with reduced IL-10 production. Our data demonstrate that the IL-10 pathway plays a chief role in lupus pathogenesis. It indicates that JC virus-like particles represent a potent vector for delivering interfering RNA in vivo. They suggest that RNA interference targeting IL-10 is an effective strategy to silence the IL-10 pathway, and possesses a therapeutic potential that could be useful in the management of SLE and, possibly, other immune-mediated disorders.

A Mendelian Predisposition to B Cell Lymphoma Caused by IL-10R2 Deficiency

AbstractAbstract 5092 BackgroundThe fact that monogenic interleukin (IL)-10 and IL-10 receptor deficiencies cause very early-onset, severe inflammatory bowel disease demonstrates the IL-10 pathway's crucial role in preventing microbiota-driven gut inflammation. However, no other severe complications of IL-10/IL-10R deficiencies have been reported to date. MethodsA cohort of six patients with IL-10/IL-10R deficiency was retrospectively surveyed for phenotypic expression. The identification of a number of cases of lymphoma prompted an in-depth characterization of available biopsy material, with immunohistochemical staining, cytogenetic studies and gene expression profiling. ResultsFour patients (all with a complete IL-10R2 deficiency) had developed B cell non-Hodgkin’s lymphoma between the ages of 5 and 6 years. Cytogenetic and IgH clonality analyses suggested that one of the patients developed at least 3 distinct lymphomas. The patients’ tumors had the characteristics of diffuse large B cell lymphomas and contained monoclonal, Epstein-Barr-virus-negative germinal center B cells. Nuclear expression of the NF-κB factor c-REL was detected in all of the six lymphomas tested. ConclusionsIL-10R deficiency is associated with a high risk of developing a B cell lymphoma with an unusual phenotype. Our results highlight an unexpected role of the IL-10R pathway in the control of lymphomagenesis. Disclosures:No relevant conflicts of interest to declare.

The T Cell Response to IL-10 Alters Cellular Dynamics and Paradoxically Promotes Central Nervous System Autoimmunity

IL-10 is a critical anti-inflammatory cytokine, the deficiency of which leads to spontaneous autoimmunity. However, therapeutically administered or ectopically expressed IL-10 can either suppress or promote disease. Distinct lineage-specific activities may explain the contradictory effects of IL-10. To dissect the T cell-specific response to IL-10 during organ-specific autoimmunity, we generated mice with a selective deletion of IL-10Rα in T cells and analyzed its effects in an autoimmune model, experimental allergic encephalomyelitis (EAE). Surprisingly, the T cell response to IL-10 increased EAE severity. This did not result from altered T cell functional potential; T cell cytokine profile was preserved. IL-10 also diminished the proliferation of T cells in situ within the target organ, an effect that would be expected to restrain disease. However, IL-10 acted cell autonomously to sustain the autoreactive T cells essential for immunopathogenesis, promoting their accumulation and distorting the regulatory and effector T cell balance. Indeed, in chimeric mice and after adoptive transfer, wild type T cells showed a competitive advantage over cells deficient in IL-10Rα. Therefore, T cell specific actions of IL-10 can support autoimmune inflammation, and this appears to result from an overall increase in the long term fitness of pathologic T cells. Lineage-restricted, disease-promoting activities of IL-10 should be considered in the therapeutic manipulation of the IL-10 pathway.

Gender-Specific Cytokine Pathways, Targets, and Biomarkers for the Switch from Health to Adenoma and Colorectal Cancer

Studies focusing on gender have shown that differences exist in how the immune system responds to disease and therapy. Understanding how gender influences immunological mechanisms in health and disease and identifying gender-specific biomarkers could lead to specifically tailored treatment and ultimately improve therapeutic success rates. T helper1 (Th1) and Th2 cytokines (Th1/Th2) have pivotal roles in the homeostasis of Th1 and Th2 cell network functions in the immune response but sex steroids affect Th1/Th2 production in different ways and a natural sexual dimorphism in the immune response has been shown. In order to investigate these differences further, we developed Th-cytokine data-driven models of the immune response and evaluated healthy subject peripheral blood samples. Independent cohorts of colorectal cancer and adenoma patients were also studied for comparison purposes. Our results show that the interferon (IFN)γ production pathway for immune response homeostasis is specific to men whilst the interleukin- (IL-) 6 production pathway for immune response homeostasis is specific to women. The IL-10 pathway for restoring immune system resting homeostasis was common to both but was controlled by the respective gender-specific pathways. These gender pathways could well be used as targets and biomarkers in translational research into developing new clinical strategies.

Attenuation of innate immunity by cytomegalovirus IL-10 establishes a long-term deficit of adaptive antiviral immunity

Human cytomegalovirus (HCMV) and many other pathogens exploit the IL-10 pathway, as part of their infectious cycle, either through their own encoded IL-10 (hcmvIL-10 for HCMV) or manipulation of the cellular IL-10 signaling cascade. Based on the in vitro demonstrations of its pleiotropic and cell type-dependent modulatory nature, hcmvIL-10 could profoundly attenuate host immunity, facilitating the establishment and maintenance of a persistent infection in an immune-competent host. To investigate the impact of extrinsic IL-10 on the induction and maintenance of antiviral immune responses in vivo, rhesus macaques were inoculated with variants of rhesus cytomegalovirus (RhCMV) either expressing or lacking the RhCMV ortholog of hcmvIL-10 (rhcmvIL-10). The results show that rhcmvIL-10 alters the earliest host responses to viral antigens by dampening the magnitude and specificity of innate effector cells to primary RhCMV infection. In addition, there is a commensurate reduction in the quality and quantity of early and long-term, RhCMV-specific adaptive immune responses. These findings provide a mechanistic basis of how early interactions between a newly infected host and HCMV could shape the long-term virus-host balance, which may facilitate the development of new prevention and intervention strategies for HCMV.

IgG1 Is Pathogenic in Leishmania mexicana Infection

There are >2 million new cases of leishmaniasis annually, and no effective vaccine has been developed to prevent infection. In murine infection, Leishmania mexicana, which lives intracellularly in host macrophages, has developed pathways to hijack host IgG to induce a suppressive IL-10 response through FcγRs, the cell-surface receptors for IgG. To guide vaccine development away from detrimental Ab responses, which can accompany attempts to induce cell-mediated immunity, it is crucial to know which isotypes of IgG are pathogenic in this infection. We found that IgG1 and IgG2a/c induce IL-10 from macrophages in vitro equally well but through different FcγR subtypes: IgG1 through FcγRIII and IgG2a/c through FcγRI primarily, but also through FcγRIII. In sharp contrast, mice lacking IgG1 develop earlier and stronger IgG2a/c, IgG3, and IgM responses to L. mexicana infection and yet are more resistant to the infection. Thus, IgG1, but not IgG2a/c or IgG3, is pathogenic in vivo, in agreement with prior studies indicating that FcγRIII is required for chronic disease. This calls into question the assumption that macrophages, which should secrete IL-10 in response to IgG1 and IgG2a/c immune complexes, are the most important source of IL-10 generated by IgG-FcγR engagement in L. mexicana infection. Further investigations are required to better determine the cell type responsible for this immunosuppressive FcγRIII-induced IL-10 pathway and whether IgG2a/c is protective.

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To the Editor: We would like to thank Dr. Leng and colleagues for their interest in our work. Our report focused on the modulation of T cell activity by 1,25(OH)2D3, with an emphasis on Th17 and T cell cytokine expression. Our findings demonstrated that 1,25(OH)2D3 has a suppressive effect on human IL-17A and IL-17F production. Importantly, we noted a direct (monocyte-independent) inhibitory effect of 1,25(OH)2D3, but not dexamethasone, on human Th17 polarization and human Th17 cytokine production in patients with early RA. We fully agree with Leng and colleagues that the precise molecular mechanism of how vitamin D modulates Th17 activity and corticosteroid-induced osteoporosis needs further investigation. Leng et al suggest that the vitamin D–induced IL-10 pathway may be critical and that 1,25(OH)2D3 treatment may be insufficient to prevent corticosteroid-induced osteoporosis in patients with early RA who have a defect in the IL-10/IL-10R pathway. The question is whether the 1,25(OH)2D3 effect is completely IL-10 dependent. We found an increase in IL-10 expression by 1,25(OH)2D3-treated peripheral blood mononuclear cells from healthy volunteers and patients with early RA. However, in fluorescence-activated cell sorted memory T cells from patients with early RA, 1,25(OH)2D3 did not up-regulate IL-10 expression although lower IL-17A levels were found (Lubberts E, et al: unpublished observations). This suggests that IL-10 can help in the suppressive effect of 1,25(OH)2D3 on human T cell activity, but that the suppressive effect on IL-17A is not completely IL-10 dependent and that other pathways may be involved as well. Further research is needed to unravel the precise molecular mechanism, including the role of the IL-10/IL-10R pathway in the suppressive behavior of 1,25(OH)2D3 on T cell biology and corticosteroid-induced osteoporosis, before it can be concluded that 1,25(OH)2D3 may be insufficient to prevent corticosteroid-induced osteoporosis in RA.

IL10 and IL10 receptor gene variation and outcomes after unrelated and related hematopoietic cell transplantation.

Results of a previous study with human leukocyte antigen (HLA)-identical siblings showed individual and synergistic associations of single nucleotide polymorphisms in the promoter region of the recipient's IL10 gene and the donor's IL10 receptor beta (IL-10RB) gene with development of grades III-IV acute graft-versus-host disease (GVHD) after allogeneic hematopoietic cell transplantation. In this study of 936 patients who had unrelated donors, genotypes of single nucleotide polymorphisms in the IL10 gene and the IL-10RB gene were evaluated as correlates with outcomes after transplantation. We found no statistically significant associations of polymorphisms at positions -3575, -2763, -1082, and -592 of the IL10 gene or codon 238 of the IL10RB gene with severe acute GVHD, extensive chronic GVHD or nonrelapse mortality after hematopoietic cell transplantation. Among HLA-matched unrelated pairs, the patient's IL10/-592 genotype and donor's IL10RB/c238 genotype showed trends suggesting individual and combined associations with grades III-IV acute GVHD similar to those observed among patients with HLA-identical sibling donors. Although genetic variation in IL10 pathway affects risk of acute GVHD and non-relapse mortality in HLA-identical sibling transplants, the current results indicate that genetic variation in the IL10 pathway does not significant affect these outcomes in unrelated donor transplants suggesting that the strength of the alloimmune response in the latter exceeds the anti-inflammatory activity of IL10.

Inhibition of inflammation-induced alterations in rat small intestine by the herbal preparations STW 5 and STW 6

Inflammation is a common mechanism of many gastrointestinal diseases. Therefore, it is interesting to know, whether complex phytopharmaceuticals known to modulate gastrointestinal motor function reveal also anti-inflammatory properties. We tested the fixed herbal combination product STW 5 (Iberogast((R))) and its main component Iberis amara fresh plant extract (STW 6) to characterize their protective potential in an experimental inflammation model in vitro. The test system consisted of ileum/jejunum segments from male Wistar rats. Inflammation was evoked by intraluminal instillation of 2,4,6-trinitrobenzenesulfonic acid (TNBS) for 30min. Preincubation of TNBS together with STW 5 and STW 6 prevented the TNBS-induced inhibition of ACh-induced contractions. No differences were found between water-dissolved and ethanol-dissolved extracts. STW 5 and STW 6 reduced morphological changes induced by TNBS in mucosal and muscle layers. The IL-10 mRNA measured by qRT-PCR was not influenced by TNBS but increased by STW 5 and STW 6. The TNBS-induced increase in the TNFalpha-mRNA expression was suppressed by STW 5 but not by STW 6. Additionally, STW 5 decreased TNFalpha release in LPS-stimulated human monocytes. STW 6 influenced neither the TNFalpha-mRNA nor the TNFalpha release. These findings demonstrate that STW 5 reduced inflammation-induced alterations in ileum/jejunum segments. The effects were associated with a restoration of the disturbed ACh-induced contraction, pathohistological protection and inhibition of TNFalpha. STW 6 may contribute to the protective effect of STW 5 mainly by increasing IL-10 pathway but not by influencing TNFalpha.

Interleukin-23 Restrains Regulatory T Cell Activity to Drive T Cell-Dependent Colitis

SummaryInterleukin-23 (IL-23) is an inflammatory cytokine that plays a key role in the pathogenesis of several autoimmune and inflammatory diseases. It orchestrates innate and T cell-mediated inflammatory pathways and can promote T helper 17 (Th17) cell responses. Utilizing a T cell transfer model, we showed that IL-23-dependent colitis did not require IL-17 secretion by T cells. Furthermore, IL-23-independent intestinal inflammation could develop if immunosuppressive pathways were reduced. The frequency of naive T cell-derived Foxp3+ cells in the colon increased in the absence of IL-23, indicating a role for IL-23 in controlling regulatory T cell induction. Foxp3-deficient T cells induced colitis when transferred into recipients lacking IL-23p19, showing that IL-23 was not essential for intestinal inflammation in the absence of Foxp3. Taken together, our data indicate that overriding immunosuppressive pathways is an important function of IL-23 in the intestine and could influence not only Th17 cell activity but also other types of immune responses.

Vertical Infraclavicular Block of the Brachial Plexus: Effects on Hemidiaphragmatic Movement and Ventilatory Function

Several case reports have suggested that block of the brachial plexus by the vertical infraclavicular approach influences hemidiaphragmatic movement and ventilatory function. These effects have not been evaluated in a prospective study. Thirty-five consecutive patients scheduled for elective surgery under brachial plexus anesthesia were included. A vertical infraclavicular block was performed with ropivacaine 0.75%, 0.5 mL/kg. Ipsilateral hemidiaphragmatic movement was measured by ultrasonography at maximal forced inspiration and sniff. Forced vital capacity (FVC) and forced expiratory volume (FEV(1)) were measured by a portable vitalograph. All measurements were performed before the block procedure and at 5, 10, 30, and 60 minutes after the block. The block was successful in 34 of 35 patients. In 9 patients (26%), a change in hemidiaphragmatic movement (reduced or paradoxical) was observed. A significant decrease in ventilatory function was found in 8 of these 9 patients between baseline and at 60 minutes: FVC = -0.8 +/- 0.4 L and FEV(1) = -0.7 +/- 0.3 L, mean +/- SD (relative decrease: FVC = 30 +/- 14% and FEV(1) = 32 +/- 13%, mean +/- SD). Horner's syndrome was seen in 4 patients (12%), and in all, a change in hemidiaphragmatic movement was observed. No clinical signs of ventilatory dysfunction were noticed. The vertical infraclavicular block can result in a change in ipsilateral hemidiaphragmatic movement, with a decrease of ventilatory function. Although a correlation between the presence of Horner's syndrome and hemidiaphragmatic dysfunction was observed, hemidiaphragmatic dysfunction also occurred independently.

Inactivation of Myc in Murine Two-Hit B lymphomas Causes Dormancy with Elevated Levels of Interleukin 10 Receptor and CD20: Implications for Adjuvant Therapies

Overexpression of c-Myc and inactivation of p53 are hallmarks of human Burkitt's lymphomas. We had previously showed that transduction of murine p53-null bone marrow cells with a Myc-encoding retrovirus is sufficient for B lymphomagenesis. To address the role of Myc in tumor sustenance, we generated lymphomas induced by the Myc-estrogen receptor fusion protein (MycER). Engrafted hosts were continuously treated with the ER ligand 4-hydroxytamoxifen (4-OHT) to allow tumor formation. Subsequent inactivation of MycER via 4-OHT deprivation resulted in tumor stasis but only partial regression. At the cellular level, dormant neoplastic lymphocytes withdrew from mitosis and underwent further B-cell differentiation. Concomitantly, they up-regulated genes involved in lymphocyte proliferation and survival, most notably interleukin 10 receptor alpha (IL10Ralpha) and CD20, the target for antibody therapy with Rituxan. We found that overexpression of IL10Ralpha affords significant proliferative advantages and in 4-OHT-deprived animals correlates with eventual tumor relapse. Both dormant and relapsing tumors maintain IL10Ralpha expression suggesting that they might be sensitive to emerging drugs targeting the IL-10 pathway. Up-regulation of CD20 following Myc inactivation was also observed in immortalized human lymphocytes. Importantly, in this system, Myc(OFF)CD20(HIGH) cells were more prone to Rituxan-induced apoptosis than Myc(ON)CD20(MED). Thus, targeting Myc, while moderately effective on its own, shapes the phenotype of dormant neoplastic cells and sensitizes them to adjuvant molecular therapies.

Carcinoembryonic antigen promotes tumor cell survival in liver through an IL-10-dependent pathway

Most circulating tumor cells die within 24 h of entering the hepatic microvasculature because their arrest initiates an ischemia-reperfusion (I/R) injury that is cytotoxic. Human colorectal carcinomas (CRC) produce the glycoprotein Carcinoembryonic Antigen (CEA) that increases experimental liver metastasis in nude mice. Since CEA induces release of IL-6 and IL-10, we hypothesized that CEA inhibits the I/R injury through a Kupffer cell-mediated cytokine-dependent pathway. We assessed cytokine effects in CRC co-cultured with liver and in vivo. Human CRC prelabeled with fluorescent dyes were incubated with a reoxygenated suspension of ischemic nude mouse liver fragments in a bioreactor. CEA, rhIL-6 or rhIL-10 were either administered to the donor mice prior to hepatic ischemia or during co-culture. Liver donors were athymic nude or iNOS, IL-6 or IL-10 knock out mice. Ischemic-reoxygenated liver kills Clone A CRC through production of nitric oxide (NO) and superoxide anion. Treatment of liver donors with CEA prior to hepatic ischemia inhibited this in vitro cytotoxicity through an IL-10 and Kupffer cell dependent pathway that inhibited NF-kappaB activation, NO production and iNOS upregulation. IL-10 but not IL-6 enhanced CRC survival in nude mouse liver in vivo. Thus, CEA enhanced metastasis by inducing IL-10 to inhibit iNOS upregulation in host liver.

Association of IL-10 and IL-10 Receptor Gene Polymorphisms and Graft-Versus-Host Disease Following Hematopoietic Cell Transplantation.

Polymorphisms in cytokine genes can influence immune responses and may affect the outcome of hematopoietic cell transplantation (HCT). We have shown that the IL-10/-592*A allele of the recipient is a marker for less severe acute graft-versus-host disease (GVHD) and a lower risk of non-relapse mortality (NRM) after HCT from an HLA-identical sibling (N Engl J Med, 2003). To further test the hypothesis that IL-10 pathway is important in the intensity of acute GVHD, we undertook a study of variation in the IL-10 receptor β gene. A single nucleotide polymorphism (A/G) at cDNA position 238 of the IL-10 receptor β gene (IL-10RB/1304) was genotyped in 953 HCT recipients and their HLA-identical sibling donors. IL-10/-592 and IL-10RB alleles and genotypes were tested for association with GVHD by multivariable analysis. The IL-10/-592*A allele of the recipient and IL-10RB/238*G allele of the donor were significantly associated with a lower risk of acute grades III-IV GVHD (trend p value 0.0008 and 0.02, respectively). None of the 16 cases with a patient IL-10 A/A genotype and donor IL-10RB G/G genotype developed grades III-IV acute GVHD (HR = 0.0 and p value = 0.007), compared to pairs with a patient IL-10 C/C genotype and donor IL-10RB A/A genotype. The hazard ratios were 0.4–0.6 among pairs with a patient IL-10 A/A genotype and donor IL-10RB A/G or A/A genotype and among pairs with a patient IL-10 A/C genotype and donor IL-10RB G/G or A/G genotype. The effect of donor IL-10RB genotype on GVHD was observed only among pairs with a patient IL-10 A/C or A/A genotype (trend p value = 0.005 and 0.06 respectively), but not among pairs with a patient IL-10 C/C genotype (trend p value = 0.82). These data suggest an interaction in the effect of the patient IL-10/-592 and donor IL-10RB/1304 genotypes on GVHD, further supporting the hypothesis that the IL-10 pathway plays an important role in controlling the severity of acute GVHD.

Novel variants of the IL-10 receptor 1 affect inhibition of monocyte TNF-alpha production.

IL-10-deficient mice exhibit spontaneous enterocolitis and other symptoms akin to Crohn's disease, indicating that IL-10 might regulate normal physiology in the gut. However, clinical trials with IL-10 in Crohn's disease were disappointing, although some patients showed healing of intestinal mucosa. This study searched for genetic polymorphisms within the IL-10 pathway. We decided to screen for mutations of the IL-10R1 cDNA in healthy volunteers and Crohn's disease patients and identified two novel variants: a serine 138-to-glycine (S138G) and a glycine 330-to-arginine (G330R) substitution. The allelic frequency in a European cohort was relatively high (16% for the S138G and 33% for the G330R), and S138G was in strong linkage disequilibrium with G330R. A similar allele frequency was found in a group of Crohn's patients. In IL-10R1 G330R-expressing monocytes, the inhibitory effect of IL-10 on TNF-alpha production was diminished, indicating that this variant may be a loss-of-function allele. No such difference was observed between haplotypes 4 (G330R only) and 7 (S138G and G330R). In addition, these IL-10R1 variants had no influence on the IL-10R1 expression density. Structural analysis of the S138G variant revealed that the substitution of S138G may interfere with binding of IL-10 to IL-10R1.