Interleukin-10 (IL-10) is an immunoregulatory cytokine with both anti-inflammatory and immunostimulatory properties and is frequently dysregulated in disease. We used a structure-based approach to ...deconvolute IL-10 pleiotropy by determining the structure of the IL-10 receptor (IL-10R) complex by cryo-electron microscopy at a resolution of 3.5 angstroms. The hexameric structure shows how IL-10 and IL-10Rα form a composite surface to engage the shared signaling receptor IL-10Rβ, enabling the design of partial agonists. IL-10 variants with a range of IL-10Rβ binding strengths uncovered substantial differences in response thresholds across immune cell populations, providing a means of manipulating IL-10 cell type selectivity. Some variants displayed myeloid-biased activity by suppressing macrophage activation without stimulating inflammatory CD8
T cells, thereby uncoupling the major opposing functions of IL-10. These results provide a mechanistic blueprint for tuning the pleiotropic actions of IL-10.
Interleukin (IL)-10 is an immune-regulatory cytokine with multiple functions. In the current study, IL-10 and its two receptors, IL-10R1 and IL-10R2 were identified in mandarin fish, Siniperca ...chuatsi. The inhibitory effect of mandarin fish IL-10 was investigated on pro-inflammatory cytokine expression and the ligand-receptor relationship. This IL-10 possesses conserved cysteine residues, predicted α-helices and a typical IL-10 family signature motif, similar to its mammalian orthologue, and IL-10R1 harbours predicted JAK1 and STAT3 binding sites in the intracellular region. The fish IL-10 and IL-10R1 exhibit high expression levels in several immune-related organs/tissues, such as spleen, trunk kidney and head kidney, and IL-10R2 possesses a constitutive expression pattern. The expression of IL-10 shows significant increase in spleen from infectious spleen and kidney necrosis virus (ISKNV) infected mandarin fish, where the two receptors also exhibit different levels of induced expression. Mandarin fish IL-10 also exhibits significant response to the stimulation of LPS, PHA and PMA, with the two receptors exhibiting an interesting decrease in expression following the treatment of PMA. The pro-inflammatory cytokines, IL-6, IL-1β, IL-8, TNF-α, show diminished up-regulation in LPS-stimulated splenocytes pre-incubated with IL-10, indicating the anti-inflammatory roles of mandarin fish IL-10. In EPC cells transfected with different combinations of receptors, IL-10 can enhance the expression of suppressor of cytokine signalling 3 (SOCS3) only when IL-10R1 and IL-10R2 are both expressed, suggesting the participation of the two receptors in signal transduction of mandarin fish IL-10. Similar results are observed with the usage of chimeric receptors, IL-10R1/CRFB1 and IL-10R2/CRFB5. Overall, mandarin fish IL-10 shares conserved ligand-receptor system and the prototypical inhibitory activities on pro-inflammatory cytokine expression with mammalian IL-10, implying the evolutionary conservation of this cytokine.
•IL-10 and its receptors, IL-10R1 and IL-10R2, were identified in mandarin fish S. chuatsi.•IL-10 and IL-10R1 contain conserved sequences for disulfide bridges, and JAK1 and STAT3 binding, respectively.•SOCS3 in splenocytes from mandarin fish had increased mRNA levels following stimulation of IL-10.•IL-10 had an inhibitory effect on the expression of IL-6, IL-1β, IL-8, TNF-α genes and on oxygen radical production.•The ligand-receptor relationship between IL-10 and IL-10R1, IL-10R2 were characterized experimentally.
Background & Aims Homozygous loss of function mutations in interleukin-10 ( IL10 ) and interleukin-10 receptors ( IL10R ) cause severe infantile (very early onset) inflammatory bowel disease (IBD). ...Allogeneic hematopoietic stem cell transplantation (HSCT) was reported to induce sustained remission in 1 patient with IL-10R deficiency. We investigated heterogeneity among patients with very early onset IBD, its mechanisms, and the use of allogeneic HSCT to treat this disorder. Methods We analyzed 66 patients with early onset IBD (younger than 5 years of age) for mutations in the genes encoding IL-10, IL-10R1, and IL-10R2. IL-10R deficiency was confirmed by functional assays on patients' peripheral blood mononuclear cells (immunoblot and enzyme-linked immunosorbent assay analyses). We assessed the therapeutic effects of standardized allogeneic HSCT. Results Using a candidate gene sequencing approach, we identified 16 patients with IL-10 or IL-10R deficiency: 3 patients had mutations in IL-10, 5 had mutations in IL-10R1, and 8 had mutations in IL-10R2. Refractory colitis became manifest in all patients within the first 3 months of life and was associated with perianal disease (16 of 16 patients). Extraintestinal symptoms included folliculitis (11 of 16) and arthritis (4 of 16). Allogeneic HSCT was performed in 5 patients and induced sustained clinical remission with a median follow-up time of 2 years. In vitro experiments confirmed reconstitution of IL-10R−mediated signaling in all patients who received the transplant. Conclusions We identified loss of function mutations in IL-10 and IL-10R in patients with very early onset IBD. These findings indicate that infantile IBD patients with perianal disease should be screened for IL-10 and IL-10R deficiency and that allogeneic HSCT can induce remission in those with IL-10R deficiency.
•IL-10 is one of the most potent anti-inflammatory cytokine.•IL-10 therapeutic potential have been hard to harness.•Most of the therapeutic strategies are based on provision of exogenous ...IL-10.•Modifications of delivery modes of IL-10 might yield only incremental advances.•New therapeutic strategies that protect natural IL-10 sources may prove efficacious.
Interleukin-10 (IL-10) is arguably the most potent anti-inflammatory cytokine. It is produced by almost all the innate and adaptive immune cells. These cells also serve as its targets, indicating that IL-10 secretion and action is highly regulated and perhaps compartmentalized. Consistent with this notion, various efforts directed at systemic administration of IL-10 to modulate autoimmune diseases (type 1 diabetes, multiple sclerosis, rheumatoid arthritis, psoriasis) have produced conflicting and largely inconsequential effects. On the other hand, IL-10 can promote humoral immune responses, enhancing class II expression on B cells and inducing immunoglobulin (Ig) production. Consequently, the high IL-10 level in systemic lupus erythematosus (SLE) patients is considered pathogenic and its blockade ameliorates the disease. In this perspective, we review preclinical findings and results of recent clinical studies using exogenous IL-10 to treat the aforementioned autoimmune diseases. In addition, given the limited success of IL-10 supplementation, we suggest that future studies should be expanded beyond modulating the delivery modes to include developing new strategies to protect and replenish the endogenous sources of IL-10. As an example, we provide evidence that aberrant Fas-mediated deletion of IL-10-producing B cells subverts the immunoregulatory role of IL-10 in autoimmune diabetes and that modulation of the Fas pathway preserves the IL-10-producing B cells and completely protects NOD mice from developing the disease.
Inflammation has significant roles in all phases of tumor development, including initiation, progression and metastasis. Interleukin-10 (IL-10) is a well-known immuno-modulatory cytokine with an ...anti-inflammatory activity. Lack of IL-10 allows induction of pro-inflammatory cytokines and hinders anti-tumor immunity, thereby favoring tumor growth. The IL-10 network is among the most important paths linking cancer and inflammation. The simple node-and-edge network representation is useful, but limited, hampering the understanding of the mechanistic details of signaling pathways. Structural networks complete the missing parts, and provide details. The IL-10 structural network may shed light on the mechanisms through which disease-related mutations work and the pathogenesis of malignancies.
Using PRISM (a PRotein Interactions by Structural Matching tool), we constructed the structural network of IL-10, which includes its first and second degree protein neighbor interactions. We predicted the structures of complexes involved in these interactions, thereby enriching the available structural data. In order to reveal the significance of the interactions, we exploited mutations identified in cancer patients, mapping them onto key proteins of this network. We analyzed the effect of these mutations on the interactions, and demonstrated a relation between these and inflammation and cancer. Our results suggest that mutations that disrupt the interactions of IL-10 with its receptors (IL-10RA and IL-10RB) and α2-macroglobulin (A2M) may enhance inflammation and modulate anti-tumor immunity. Likewise, mutations that weaken the A2M-APP (amyloid precursor protein) association may increase the proliferative effect of APP through preventing β-amyloid degradation by the A2M receptor, and mutations that abolish the A2M-Kallikrein-13 (KLK13) interaction may lead to cell proliferation and metastasis through the destructive effect of KLK13 on the extracellular matrix.
Prediction of protein-protein interactions through structural matching can enrich the available cellular pathways. In addition, the structural data of protein complexes suggest how oncogenic mutations influence the interactions and explain their potential impact on IL-10 signaling in cancer and inflammation.
A defining characteristic of persistent viral infections is the loss and functional inactivation of antiviral effector T cells, which prevents viral clearance. Interleukin-10 (IL-10) suppresses ...cellular immune responses by modulating the function of T cells and antigen-presenting cells. In this paper, we report that IL-10 production is drastically increased in mice persistently infected with lymphocytic choriomeningitis virus. In vivo blockade of the IL-10 receptor (IL-10R) with a neutralizing antibody resulted in rapid resolution of the persistent infection. IL-10 secretion was diminished and interferon gamma production by antiviral CD8+ T cells was enhanced. In persistently infected mice, CD8alpha+ dendritic cell (DC) numbers declined early after infection, whereas CD8alpha- DC numbers were not affected. CD8alpha- DCs supported IL-10 production and subsequent dampening of antiviral T cell responses. Therapeutic IL-10R blockade broke the cycle of IL-10-mediated immune suppression, preventing IL-10 priming by CD8alpha- DCs and enhancing antiviral responses and thereby resolving infection without causing immunopathology.
Interleukin (IL)-10, an immune-regulatory cytokine, exerts various biological functions through interaction with IL-10 receptors. In teleost, very limited functional studies on IL-10 receptors have ...been documented. In this study, we reported the expression patterns of IL-10 receptor 1 (CsIL-10R1) and receptor 2 (CsIL-10R2) of tongue sole (Cynoglossus semilaevis) and examined their biological properties. The expression of CsIL-10R1 and CsIL-10R2 occurred in multiple tissues and were regulated by bacterial challenge. In vitro binding studies showed that recombinant extracellular region of CsIL-10R1 (rCsIL-10R1ex) rather than rCsIL-10R2ex could bind with rCsIL-10. Cellular study showed that both CsIL-10R1 and CsIL-10R2 were expressed on peripheral blood leukocytes (PBLs), and blockade of CsIL-10R1 or CsIL-10R2 by antibody could reduce inhibitory effect of CsIL-10 on ROS production of PBLs. When injected in vivo, anti-rCsIL-10R1 or anti-rCsIL-10R2 antibody dramatically promoted the expression of proinflammatory cytokines and suppressed bacterial dissemination in tongue sole tissues. Consistently, the overexpression of CsIL-10R1 or CsIL-10R2 significantly enhanced bacterial dissemination, and the overexpression of CsIL-10R1M bearing STAT3 site mutation reduced bacterial dissemination. Overall, these results demonstrate for the first time teleost IL-10 receptors play a negative role in antibacterial immunity and add insight into the function of CsIL-10 receptors.
•Expressions of CsIL-10 receptors were found in multiple tissues and upregulated or downregulated by bacterial infection.•CsIL-10 receptors were expressed on PBLs, CsIL-10R1 instead of CsIL-10R2 directly bound with CsIL-10.•Blocking CsIL-10 receptors markedly reduced the inhibitory effect of CsIL-10 on ROS production of PBL.•Blocking CsIL-10 receptors markedly promoted the expression of proinflammatory cytokines and suppressed bacterial infection.
Interleukin‐10 (IL‐10) has long been recognized to have potent and broad‐spectrum anti‐inflammatory activity, which has been unequivocally established in various models of infection, inflammation, ...and even in cancer. However, because of the marginal successes of the initial clinical trials using recombinant IL‐10, some of the interest in this cytokine as an anti‐inflammatory therapeutic has diminished. New work showing IL‐10 production from regulatory T cells and even T‐helper 1 T cells has reinvigorated the field and revealed the power of this cytokine to influence immune responses. Furthermore, new preclinical studies suggest that combination therapies, using antibodies to IL‐10 along with chemotherapy, can be effective in treating bacterial, viral, or neoplastic diseases. Studies to understand IL‐10 gene expression in the various cell types may lead to new therapeutics to enhance or inhibit IL‐10 production. In this review, we summarize what is known about the regulation of IL‐10 gene expression by various immune cells. We speculate on the promise that this cytokine holds to influence immune responses and mitigate immune pathologies.
The molecular cause of inflammatory bowel disease is largely unknown.
We performed genetic-linkage analysis and candidate-gene sequencing on samples from two unrelated consanguineous families with ...children who were affected by early-onset inflammatory bowel disease. We screened six additional patients with early-onset colitis for mutations in two candidate genes and carried out functional assays in patients' peripheral-blood mononuclear cells. We performed an allogeneic hematopoietic stem-cell transplantation in one patient.
In four of nine patients with early-onset colitis, we identified three distinct homozygous mutations in genes IL10RA and IL10RB, encoding the IL10R1 and IL10R2 proteins, respectively, which form a heterotetramer to make up the interleukin-10 receptor. The mutations abrogate interleukin-10-induced signaling, as shown by deficient STAT3 (signal transducer and activator of transcription 3) phosphorylation on stimulation with interleukin-10. Consistent with this observation was the increased secretion of tumor necrosis factor alpha and other proinflammatory cytokines from peripheral-blood mononuclear cells from patients who were deficient in IL10R subunit proteins, suggesting that interleukin-10-dependent "negative feedback" regulation is disrupted in these cells. The allogeneic stem-cell transplantation performed in one patient was successful.
Mutations in genes encoding the IL10R subunit proteins were found in patients with early-onset enterocolitis, involving hyperinflammatory immune responses in the intestine. Allogeneic stem-cell transplantation resulted in disease remission in one patient.
Highlights • The role of IL-10 in tumorigenesis and development is still controversial. • One explanation is the balance of cytokines and other conditions delicately controlling its function in ...different cell types. • It is also possible that IL-10 might play a dual role in tumorigenesis and development.