Showing papers by "Charles A. Dinarello published in 2009"
TL;DR: The IL-1 family includes members that suppress inflammation, both specifically within the IL-2 family but also nonspecifically for TLR ligands and the innate immune response.
Abstract: More than any other cytokine family, the interleukin (IL)-1 family is closely linked to the innate immune response. This linkage became evident upon the discovery that the cytoplasmic domain of the IL-1 receptor type I is highly homologous to the cytoplasmic domains of all Toll-like receptors (TLRs). Thus, fundamental inflammatory responses such as the induction of cyclooxygenase type 2, increased expression of adhesion molecules, or synthesis of nitric oxide are indistinguishable responses of both IL-1 and TLR ligands. Both families nonspecifically affect antigen recognition and lymphocyte function. IL-1β is the most studied member of the IL-1 family because of its role in mediating autoinflammatory diseases. Although the TLR and IL-1 families evolved to assist in host defense against infection, unlike the TLR family, the IL-1 family also includes members that suppress inflammation, both specifically within the IL-1 family but also nonspecifically for TLR ligands and the innate immune response.
3,032 citations
TL;DR: It is demonstrated that human blood monocytes release processed IL-1beta after a one-time stimulation with either TLR2 or TLR4 ligands, resulting from constitutively activated caspase-1 and release of endogenous adenosine triphosphate.
733 citations
TL;DR: The results indicate that IL-1β signaling in T cells markedly induces robust and durable primary and secondary CD4 responses.
Abstract: IL-1 causes a marked increase in the degree of expansion of naive and memory CD4 T cells in response to challenge with their cognate antigen. The response occurs when only specific CD4 T cells can respond to IL-1β, is not induced by a series of other cytokines and does not depend on IL-6 or CD-28. When WT cells are primed in IL-1R1−/− recipients, IL-1 increases the proportion of cytokine-producing transgenic CD4 T cells, especially IL-17- and IL-4-producing cells, strikingly increases serum IgE levels and serum IgG1 levels. IL-1β enhances antigen-mediated expansion of in vitro primed Th1, Th2, and Th17 cells transferred to IL-1R1−/− recipients. The IL-1 receptor antagonist diminished responses to antigen plus lipopolysaccharide (LPS) by ≈55%. These results indicate that IL-1β signaling in T cells markedly induces robust and durable primary and secondary CD4 responses.
502 citations
TL;DR: It is suggested that inhibitors of caspase 1 are not able to interfere with the whole spectrum of IL-1beta production, and therefore such inhibitors may be of therapeutic value only in inflammatory conditions in which limited numbers of neutrophils are present.
Abstract: OBJECTIVE: Caspase 1, a known cysteine protease, is a critical component of the inflammasome. Both caspase 1 and neutrophil serine proteases such as proteinase 3 (PR3) can process pro-interleukin-1beta (proIL-1beta), a crucial cytokine linked to the pathogenesis of rheumatoid arthritis. This study was undertaken to establish the relative importance of caspase 1 and serine proteases in mouse models of acute and chronic inflammatory arthritis. METHODS: Acute and chronic arthritis were induced in caspase 1-/- mice, and the lack of caspase 1 was investigated for its effects on joint swelling, cartilage metabolism, and histopathologic features. In addition, caspase 1 activity was inhibited in mice lacking active cysteine proteases, and the effects of dual blockade of caspase 1 and serine proteases on arthritis severity and histopathologic features were evaluated. RESULTS: Surprisingly, caspase 1-/- mice, in a model of acute (neutrophil-dominated) arthritis, developed joint swelling to an extent similar to that in wild-type control mice. Joint fluid concentrations of bioactive IL-1beta were comparable in caspase 1-/- mice and controls. In contrast, induction of chronic arthritis (characterized by minimal numbers of neutrophils) in caspase 1-/- mice led to reduced joint inflammation and less cartilage damage, implying a caspase 1-dependent role in this process. In mice lacking neutrophil serine PR3, inhibition of caspase 1 activity resulted in decreased bioactive IL-1beta concentrations in the synovial tissue and less suppression of chondrocyte anabolic function. In addition, dual blockade of both PR3 and caspase 1 led to protection against cartilage and bone destruction. CONCLUSION: Caspase 1 deficiency does not affect neutrophil-dominated joint inflammation, whereas in chronic arthritis, the lack of caspase 1 results in reduced joint inflammation and cartilage destruction. These findings suggest that inhibitors of caspase 1 are not able to interfere with the whole spectrum of IL-1beta production, and therefore such inhibitors may be of therapeutic value only in inflammatory conditions in which limited numbers of neutrophils are present.
300 citations
TL;DR: Interleukin-1 is a highly active proinflammatory cytokine that causes not only fever, anorexia, and other constitutional symptoms but also tissue damage and remodeling.
Abstract: Interleukin-1 is a highly active proinflammatory cytokine that causes not only fever, anorexia, and other constitutional symptoms but also tissue damage and remodeling. All these effects — includin...
204 citations
TL;DR: Targeting IL-1β has the potential to inhibit angiogenesis in pathological situations and may be of considerable clinical value, as shown by the dramatic reduction of inflammatory and angiogenic responses in Matrigel plugs that contained macrophage supernatants from control mice.
Abstract: Inflammation and angiogenesis are pivotal processes in the progression of many diseases, including malignancies. A hypoxic microenvironment often results in a milieu of proinflammatory and proangiogenic cytokines produced by infiltrating cells. We assessed the role of macrophage-derived hypoxia-associated cytokines in promoting inflammation and angiogenesis. Supernatants of macrophages, stimulated under hypoxia with or without an inflammatory stimulus (LPS), promoted angiogenesis when incorporated into Matrigel plugs. However, neutralization of IL-1 in the supernatants, particularly IL-1β, completely abrogated cell infiltration and angiogenesis in Matrigel plugs and reduced vascular endothelial growth factor (VEGF) levels by 85%. Similarly, supernatants from macrophages of IL-1β knockout mice did not induce inflammatory or angiogenic responses. The importance of IL-1 signaling in the host was demonstrated by the dramatic reduction of inflammatory and angiogenic responses in Matrigel plugs that contained macrophage supernatants from control mice which had been implanted in IL-1 receptor type I knockout mice. Myeloid cells infiltrating into Matrigel plugs were of bone marrow origin and represented the major source of IL-1 and other cytokines/chemokines in the plugs. Cells of endothelial lineage were the main source of VEGF and were recruited mainly from neighboring tissues, rather than from the bone marrow. Using the aortic ring sprouting assay, it was shown that in this experimental system, IL-1 does not directly activate endothelial cell migration, proliferation and organization into blood vessel-like structures, but rather activates infiltrating cells to produce endothelial cell activating factors, such as VEGF. Thus, targeting IL-1β has the potential to inhibit angiogenesis in pathological situations and may be of considerable clinical value.
199 citations
TL;DR: In vitro stimulation of whole blood from persons with a genetic AAT deficiency resulted in enhanced cytokine production compared with blood from healthy subjects, suggesting that endogenous AAT in blood contributes to the suppression of proinflammatory cytokine synthesis.
Abstract: Several observations suggest endogenous suppressors of inflammatory mediators are present in human blood. α-1-Antitrypsin (AAT) is the most abundant serine protease inhibitor in blood, and AAT possesses anti-inflammatory activity in vitro and in vivo. Here, we show that in vitro stimulation of whole blood from persons with a genetic AAT deficiency resulted in enhanced cytokine production compared with blood from healthy subjects. Using whole blood from healthy subjects, dilution of blood with RPMI tissue-culture medium, followed by incubation for 18 h, increased spontaneous production of IL-8, TNF-α, IL-1β, and IL-1R antagonist (IL-1Ra) significantly, compared with undiluted blood. Dilution-induced cytokine production suggested the presence of one or more circulating inhibitors of cytokine synthesis present in blood. Serially diluting blood with tissue-culture medium in the presence of cytokine stimulation with heat-killed Staphylococcus epidermidis (S. epi) resulted in 1.2- to 55-fold increases in cytokine production compared with S. epi stimulation alone. Diluting blood with autologous plasma did not increase the production of IL-8, TNF-α, IL-1β, or IL-1Ra, suggesting that the endogenous, inhibitory activity of blood resided in plasma. In whole blood, diluted and stimulated with S. epi, exogenous AAT inhibited IL-8, IL-6, TNF-α, and IL-1β significantly but did not suppress induction of the anti-inflammatory cytokines IL-1Ra and IL-10. These ex vivo and in vitro observations suggest that endogenous AAT in blood contributes to the suppression of proinflammatory cytokine synthesis.
173 citations
TL;DR: A specific target will be provided to neutralize endogenous IL‐32, which may contribute to basic and clinical immunology and to produce recombinant protein with a high yield.
Abstract: Cytokines are crucial in host defence against pathogens such as bacteria, viruses, fungi and parasites. A newly described cytokine, interleukin-32 (IL-32), induces various proinflammatory cytokines (tumour necrosis factor-alpha, IL-1beta, IL-6) and chemokines in both human and mouse cells through the nuclear factor-kappaB and p38 mitogen-activated protein kinase inflammatory signal pathway. The IL-32 primarily acts on monocytic cells rather than T cells. In an attempt to isolate the IL-32 soluble receptor, we used an IL-32 ligand-affinity column to purify neutrophil proteinase 3, which is a serine proteinase involved in many inflammatory diseases. IL-32 has biological activity associated with Mycobacterium tuberculosis and chronic proinflammatory diseases such as rheumatoid arthritis. IL-32 is transcribed as six alternative splice variants and the biological activity of each individual isoform remains unknown. Here, we cloned the complementary DNA of the four IL-32 isoforms (alpha, beta, gamma and delta) that are the most representative IL-32 transcripts. To produce recombinant protein with a high yield, the amino acids of two cysteine residues were mutated to serine residues, because serine residues are not conserved among different species. The multi-step purified recombinant IL-32 isoform proteins were assessed for their biological activities with different cytokine assays. The gamma isoform of IL-32 was the most active, although all isoforms were biologically active. The present study will provide a specific target to neutralize endogenous IL-32, which may contribute to basic and clinical immunology.
157 citations
TL;DR: IL-32 is reported to be expressed and is also functional in human vascular endothelial cells (EC) of various origins, and the properties of this cytokine relevant to coagulation, endothelial inflammation, and atherosclerosis are introduced.
Abstract: Increasing evidence demonstrates that interleukin (IL)–32 is a pro-inflammatory cytokine, inducing IL-1α, IL-1β, IL-6, tumor necrosis factor (TNF)–α, and chemokines via nuclear factor (NF)–κB, p38 mitogen-activated protein kinase (MAPK), and activating protein (AP)-1 activation. Here we report that IL-32 is expressed and is also functional in human vascular endothelial cells (EC) of various origins. Compared with primary blood monocytes, high levels of IL-32 are constitutively produced in human umbilical vein EC (HUVEC), aortic macrovascular EC, and cardiac as well as pulmonary microvascular EC. At concentrations as low as 0.1 ng/ml, IL-1β stimulated IL-32 up to 15-fold over constitutive levels, whereas 10 ng/ml of TNFα or 100 ng/ml of lipopolysaccharide (LPS) were required to induce similar quantities of IL-32. IL-1β–induced IL-32 was reduced by inhibition of the IκB kinase-β/NF-κB and ERK pathways. In addition to IL-1β, pro-coagulant concentrations of thrombin or fresh platelets increased IL-32 protein up to 6-fold. IL-1β and thrombin induced an isoform-switch in steady-state mRNA levels from IL-32α/γ to β/e. Adult EC responded in a similar fashion. To prove functionality, we silenced endogenous IL-32 with siRNA, decreasing intracellular IL-32 protein levels by 86%. The knockdown of IL-32 resulted in reduction of constitutive as well as IL-1β–induced intercellular adhesion molecule–1 (ICAM-1) (of 55% and 54%, respectively), IL-1α (of 62% and 43%), IL-6 (of 53% and 43%), and IL-8 (of 46% and 42%). In contrast, the anti-inflammatory/anti-coagulant CD141/thrombomodulin increased markedly when IL-32 was silenced. This study introduces IL-32 as a critical regulator of endothelial function, expanding the properties of this cytokine relevant to coagulation, endothelial inflammation, and atherosclerosis.
129 citations
TL;DR: It is reported that HDAC inhibition acetylates and activates STAT-3, which regulates DCs by promoting the transcription of IDO, which demonstrates a novel functional role for posttranslational modification ofSTAT-3 through acetylation and provides mechanistic insights intoHDAC inhibition-mediated immunoregulation by induction ofIDO.
Abstract: Histone deacetylase (HDAC) inhibition modulates dendritic cell (DC) functions and regulates experimental graft-vs-host disease and other immune-mediated diseases. The mechanisms by which HDAC inhibition modulates immune responses remain largely unknown. STAT-3 is a transcription factor shown to negatively regulate DC functions. In this study we report that HDAC inhibition acetylates and activates STAT-3, which regulates DCs by promoting the transcription of IDO. These findings demonstrate a novel functional role for posttranslational modification of STAT-3 through acetylation and provide mechanistic insights into HDAC inhibition-mediated immunoregulation by induction of IDO.
121 citations
TL;DR: The concept that IL-18BP genetically modified stem cells improve cardioprotection over that observed with unmodified stem cells is provided.
Abstract: IL-18 is a proinflammatory cytokine known to cause tissue injury by inducing inflammation and cell death. Increased levels of IL-18 are associated with myocardial injury after ischemia or infarction. IL-18-binding protein (IL-18BP), the naturally occurring inhibitor of IL-18 activity, decreases the severity of inflammation in response to injury. In the present study, mesenchymal stem cells (MSCs) derived from mice transgenic for over expression of human IL-18BP were tested in rat models of global myocardial ischemia and acute myocardial infarction. Improved myocardial function is associated with production of VEGF, and in vitro, IL-18BP MSCs secreted higher levels of constitutive VEGF compared to wild-type MSCs. Whereas IL-18 increased cell death and reduced VEGF in wild-type MSCs, IL-18BP MSCs were protected. In an isolated heart model, intracoronary infusion of IL-18BP MSCs before ischemia increased postischemic left ventricular (LV) developed pressure to 79.5 ± 9.47 mmHg compared to 59.3 ± 7.8 mmHg in wild-type MSCs and 37.8 ± 5 mmHg in the vehicle group. Similarly, using a coronary artery ligation model, intramyocardial injection of IL-18BP MSCs improved LV ejection fraction to 67.8 ± 1.76% versus wild-type MSCs (57.4 ± 1.33%) and vehicle (39.2 ± 2.07%), increased LV fractional shortening 1.25-fold over wild-type MSCs and 1.95-fold over vehicle, decreased infarct size to 38.8 ± 2.16% compared to 46.4 ± 1.92% in wild-type MSCs and 60.7 ± 2.2% in vehicle, reduced adverse ventricular remodeling, increased myocardial VEGF production, and decreased IL-6 levels. This study provides the concept that IL-18BP genetically modified stem cells improve cardioprotection over that observed with unmodified stem cells.
TL;DR: Passing interleukin-1 over columns containing Sepharose-coupled anti-interleuk in-1 antibody completely removed the beta cell cytotoxic action on rat islets.
Abstract: Previous electron-microscopic studies of isolated islets of Langerhans exposed to the monokine interleukin-1 for 7 days have indicated that interleukin-1 is cytotoxic to all islet cells. To study the time-course and possible cellular specificity of interleukin-1 cytotoxicity to islets exposed to interleukin-1 for short time periods, isolated rat or human islets were incubated with or without 25 U/ml highly purified human interleukin-1 for 24 h. Samples of rat islets were taken after 5 min, 30 min, 1, 2, 4, 6, 8, 10, 12, 16, 20 and 24 h and samples of human islets after 5 min, 30 min and 24 h of incubation and examined by electron microscopy in a blinded fashion. Already after 30 min, accumulation of opaque intracytoplasmic bodies without apparent surrounding membranes, and autophagic vacuoles were seen in about 20% of the beta cells examined in rat islets exposed to interleukin-1. After 16 h of incubation with interleukin-1, more than 80% of rat beta cells showed signs of degeneration. Beta cell specific changes similar to those observed in rat islets exposed to IL-1 for 30 min were seen in human islets exposed to IL-1 for 24 h. The described changes were not observed in alpha cells in interleukin-1-treated rat or human islets, or in alpha and beta cells in control islets. Passing interleukin-1 over columns containing Sepharose-coupled anti-interleukin-1 antibody completely removed the beta cell cytotoxic action on rat islets. Thus, within minutes following exposure to interleukin-1, beta cell specific ultrastructural changes were observed in isolated rat islets, whereas human islets required longer exposure to IL-1 to display equivalent morphological abnormalities.
TL;DR: It is demonstrated that IL-18 is a significant mediator of obstruction-induced renal fibrosis and epithelial- mesenchymal transition independent of downstream TGF-beta1 or TNF-alpha production.
TL;DR: It is shown that the pan‐histone deacety‐ lase (HDAC) inhibitor ITF2357, a compound shown to be safe and effective in humans, improves functional recovery and attenuates tissue damage when administered as late as 24 h postinjury.
Abstract: Despite efforts aimed at developing novel therapeutics for traumatic brain injury (TBI), no specific pharmacological agent is currently clinically available. Here, we show that the pan-histone deacetylase (HDAC) inhibitor ITF2357, a compound shown to be safe and effective in humans, improves functional recovery and attenuates tissue damage when administered as late as 24 h postinjury. Using a well-characterized, clinically relevant mouse model of closed head injury (CHI), we demonstrate that a single dose of ITF2357 administered 24 h postinjury improves neurobehavioral recovery from d 6 up to 14 d postinjury (improved neurological score vs. vehicle; P< or =0.05), and that this functional benefit is accompanied by decreased neuronal degeneration, reduced lesion volume (22% reduction vs. vehicle; P< or =0.01), and is preceded by increased acetylated histone H3 levels and attenuation of injury-induced decreases in cytoprotective heat-shock protein 70 kDa and phosphorylated Akt. Moreover, reduced glial accumulation and activation were observed 3 d postinjury, and total p53 levels at the area of injury and caspase-3 immunoreactivity within microglia/macrophages at the trauma area were elevated, suggesting enhanced clearance of these cells via apoptosis following treatment. Hence, our findings underscore the relevance of HDAC inhibitors for ameliorating trauma-induced functional deficits and warrant consideration of applying ITF2357 for this indication.
TL;DR: The present study has deciphered the pathways leading from recognition of Mycobacterium tuberculosis to the production and release of IL‐1β, the most important member of the IL-1 family, by stimulating cells defective in various pattern recognition receptors and demonstrated that IL‐ 1β production is induced by M. tuberculosis.
Abstract: Proinflammatory cytokines of the IL-1 family play an important role for the anti-mycobacterial host defense mechanisms. In the present study we have deciphered the pathways leading from recognition of Mycobacterium tuberculosis to the production and release of IL-1beta, the most important member of the IL-1 family. By stimulating cells defective in various pattern recognition receptors, we could demonstrate that IL-1beta production is induced by M. tuberculosis through pathways involving TLR2/TLR6 and NOD2 receptors. In contrast, TLR4, TLR9 and TLR1 receptors are not involved in IL-1beta induction. Recognition of M. tuberculosis by TLR and NOD2 leads to transcription of proIL-1beta through mechanisms involving ERK, p38 and Rip2, but not JNK. Interestingly, although caspase-1 is necessary for the processing of proIL-1beta, activation of caspase-1 is not dependent on the stimulation of cells by M. tuberculosis. Monocytes expressed constitutively active caspase-1. The secretion of IL-1beta is dependent on the activation of P2X7-induced pathways by endogenously released ATP. In conclusion, we have dissected the molecular mechanisms responsible for IL-1beta production by M. tuberculosis, and that may contribute to a deeper knowledge of the mechanisms of cell activation by M. tuberculosis.
TL;DR: Surprisingly, processing and secretion of IL-1beta in monocytes did not require pathogen-mediated inflammasome activation, because of the constitutive activation of caspase-1 and the capability of monocytes to release endogenous adenosine-5'-triphosphate.
Abstract: BACKGROUND: Interleukin (IL)-1beta has an important role in antifungal defense mechanisms. The inflammasome is thought to be required for caspase-1 activation and processing of the inactive precursor pro-IL-1beta. The aim of the present study was to investigate the pathways of IL-1beta production induced by Candida albicans in human monocytes. METHODS: Human mononuclear cells were stimulated with C. albicans or mutant strains defective in mannosylation or chitin. Receptors were blocked with specific antagonists, and the IL-1beta concentration was measured. RESULTS: Human primary monocytes produce bioactive IL-1beta when stimulated with C. albicans. The transcription of IL-1beta was induced through mannose receptor (MR), Toll-like receptor (TLR) 2, and dectin-1 but not through TLR4 and TLR9. N-mannan-linked residues, chitin, and beta-glucan from C. albicans are important for IL-1beta stimulation. Surprisingly, processing and secretion of IL-1beta in monocytes did not require pathogen-mediated inflammasome activation, because of the constitutive activation of caspase-1 and the capability of monocytes to release endogenous adenosine-5'-triphosphate. CONCLUSIONS: This study is the first dissection of the molecular mechanisms of IL-1beta production by a fungal pathogen. Transcription through mannan/chitin/MR and beta-glucan/dectin-1/TLR2 induces production of IL-1beta by C. albicans in human monocytes, whereas processing of IL-1beta is mediated by constitutively active caspase-1.
TL;DR: It can be concluded that IL‐18 has a multifaceted role in autoimmune lupus, being apparently involved both in the effector phases of the late organ damage and, in some organs, in the initial pathogenic events.
Abstract: Interleukin-18 (IL-18) is an inflammation-related cytokine that plays a central role both in innate defense reactions and in Th1 activation and specific immune responses. Increased levels of IL-18 can be detected in biological fluids and organs of individuals affected by several autoimmune pathologies, as well as in autoimmune animal models. In this review, the role of IL-18 in systemic lupus erythematosus (SLE) is critically examined, including its possible role in the pathogenesis of disease. In SLE, increased levels of IL-18 have been found in serum/plasma of affected persons, which positively correlated with disease severity. The possibility that circulating IL-18 levels are predictive of renal damage has been proposed, suggesting that IL-18 may be a prognostic marker of renal involvement useful to identify patients at risk of renal failure. The evaluation of urinary levels of free active IL-18 indeed suggests a correlation with the degree of renal involvement. The possible pathogenic role of IL-18 in lupus has been studied in a mouse model of progressive disease, which makes possible the identification, at the level of the different affected organs, of IL-18 changes preceding disease development and those appearing after disease onset. It can be concluded that IL-18 has a multifaceted role in autoimmune lupus, being apparently involved both in the effector phases of the late organ damage and, in some organs, in the initial pathogenic events. Therapeutic strategies targeting IL-18 in autoimmunity are under development.
TL;DR: Results indicate that a GCCT haplotype may reduce inflammation in the lung, thereby decreasing the severity of lung injury and ultimately protecting patients from mortality associated with infection-induced ALI.
Abstract: Rationale: Extracellular superoxide dismutase (EC-SOD) is a potent antioxidant that plays an important role in controlling oxidant-mediated stress and inflammation. High levels of EC-SOD are found in the lung. Acute lung injury (ALI) frequently occurs in patients with infection, and levels of EC-SOD have been shown to modulate severity of lung injury in transgenic animal models of endotoxemia-induced ALI. An R213G single nucleotide polymorphism (SNP) has been shown to alter levels of EC-SOD and patient outcomes in chronic obstructive pulmonary disease (COPD) and ischemic heart disease.
Objectives: To determine genetic variation in the promoter and EC-SOD gene and to examine whether EC-SOD haplotype blocks are associated with clinical outcomes.
Methods: We sequenced the EC-SOD promoter and gene to determine genetic variation and linkage disequilibrium (LD) patterns in a European American population. Two separate patient populations with infection-associated ALI were also evaluated to determine whether EC-SOD haplotypes were associated with clinical outcomes.
Measurements and Main Results: Sequencing resulted in the identification of 28 SNPs with relatively strong LD and 1 block consisting of 4691-5321-5360-5955-5982. This specific block was shown to be protective in two separate patient populations with infection associated ALI. In particular, patients with a GCCT haplotype had a reduced risk of time on the ventilator and mortality.
Conclusions: These results indicate that a GCCT haplotype may reduce inflammation in the lung, thereby decreasing the severity of lung injury and ultimately protecting patients from mortality associated with infection-induced ALI.
TL;DR: A role for SOCS1 and -3 in the seemingly paradoxical hyperresponsive state in cells deficient in IL-18Rα is revealed, supporting the concept that IL- 18Rα participates in both pro- and anti-inflammatory responses and that an endogenous ligand engages IL-17Rα to deliver an inhibitory signal.
TL;DR: A computational approach for predicting interacting helices was developed, and peptides that target gp96 and clusterin, 2 secreted chaperones known to shift between inactive and active conformations were designed, demonstrating a previously uncharacterized method for rational design of protein antagonists.
Abstract: Blocking conformational changes in biologically active proteins holds therapeutic promise Inspired by the susceptibility of viral entry to inhibition by synthetic peptides that block the formation of helix–helix interactions in viral envelope proteins, we developed a computational approach for predicting interacting helices Using this approach, which combines correlated mutations analysis and Fourier transform, we designed peptides that target gp96 and clusterin, 2 secreted chaperones known to shift between inactive and active conformations In human blood mononuclear cells, the gp96-derived peptide inhibited the production of TNFα, IL-1β, IL-6, and IL-8 induced by endotoxin by >80% When injected into mice, the peptide reduced circulating levels of endotoxin-induced TNFα, IL-6, and IFNγ by >50% The clusterin-derived peptide arrested proliferation of several neoplastic cell lines, and significantly enhanced the cytostatic activity of taxol in vitro and in a xenograft model of lung cancer Also, the predicted mode of action of the active peptides was experimentally verified Both peptides bound to their parent proteins, and their biological activity was abolished in the presence of the peptides corresponding to the counterpart helices These data demonstrate a previously uncharacterized method for rational design of protein antagonists
TL;DR: Investigating the effect of intravitreal anakinra on choroidal neovascularization in an animal model found that suppressing IL-1 function may provide another therapeutic avenue in exudative AMD.
Abstract: Purpose: To determine the effect of intravitreal anakinra on choroidal neovascularization (CNV) in an animal model.Methods: Laser photocoagulation used to rupture Bruch’s membrane; animals then assigned to groups based on varying frequency of intravitreal anakinra injections. At day 30, digital angiography was used to measure the CNV area. Result: Intravitreal anakinra dose-dependently inhibited CNV growth. Injections given one time resulted in a 26% reduction in CNV; in the once weekly group, a 41% reduction was seen; in the twice-weekly group, a 62% reduction was seen (all p < .001). Conclusion: Suppressing IL-1 function may provide another therapeutic avenue in exudative AMD.
TL;DR: Despite the elevatedIL-18BP levels during active disease, free IL-18 remained higher than in the inactive disease stages, suggesting a potential benefit of administration of exogenous IL- 18BP as a novel therapeutic approach for active WG.
Abstract: In the present study, we examined the levels of the pro-inflammatory cytokine IL-18 and its natural inhibitor, the IL-18 binding protein (IL-18BP), in sera of Wegener’s granulomatosis (WG) patients at various stages of the disease. Sera from eight consecutive biopsy-proven systemic WG patients (four men and four women; age at diagnosis 58.4 ± 13.8 years) were obtained longitudinally with a follow-up period of 55.2 ± 30 months. Sera obtained from 50 healthy subjects were used as controls. Serum levels of IL-18, IL-18BP, and free IL-18 obtained during an active phase of the disease (Birmingham Vasculitis Activity Score, BVAS > 10) were more than twofold higher than levels in the same patients during inactive disease stages (BVAS < 5; P < 0.002; P < 0.006, and P < 0.03 for IL-18, IL-18BP, and free IL-18, respectively). During inactive stages, the levels of these markers were comparable to those of healthy controls. The elevated levels of IL-18 and IL-18BP in sera during active stages of disease suggest a possible role in the pathogenesis and course of the WG. Despite the elevated IL-18BP levels during active disease, free IL-18 remained higher than in the inactive disease stages, suggesting a potential benefit of administration of exogenous IL-18BP as a novel therapeutic approach for active WG.
TL;DR: The significance of host-derived IL-1α in cancer immunoediting, by affecting innate and specific immunosurveillance mechanisms, is demonstrated in this study, together with previous studies, to attest to differential involvement of IL- 1α and IL-2β in tumorigenesis.
Abstract: Using IL-1/IL-1Ra knockout BALB/c mice, we showed that 3-methylcholatrene (3-MCA)-induced carcinogenesis is dependent on IL-1beta-induced inflammatory responses. Patterns of local inflammation and tumorigenicity were similar in wild-type (WT) and IL-1alpha(-/-) mice, while in IL-1beta(-/-) mice, tumorigenicity was attenuated and in IL-1Ra(-/-) mice accentuated. 3-MCA-induced fibrosarcoma cell lines from WT mice developed into progressive tumors in WT mice, while surprisingly, lines from IL-1alpha(-/-) mice formed tumors only in immunocompromized mice. 3-MCA-induced fibrosarcoma cell lines from IL-1alpha(-/-) mice, compared with lines from WT mice, manifested higher expression levels of "global" surface molecules related to Ag presentation and interactions with immune surveillance cells (MHC class I, B7.1, B7.2, L-selectin, and NKG2D ligands) and were eradicated mainly by CD4(+)- and CD8(+)-dependent T cell responses. Concomitantly, at the injection site of 3-MCA-induced fibrosarcoma cells derived from IL-1alpha(-/-) mice, a leukocyte infiltrate, subsequently replaced by a scar-like tissue, was observed. Immune aberrations in NK cell maturation, antitumor specific immunity and killing capacity of effector cells were observed in IL-1alpha(-/-) mice, in contrast to WT mice. Thus, we demonstrate in this study the significance of host-derived IL-1alpha in cancer immunoediting, by affecting innate and specific immunosurveillance mechanisms. Overall, the results presented in this study, together with our previous studies, attest to differential involvement of IL-1alpha and IL-1beta in tumorigenesis; host-derived IL-1beta mainly controls inflammation, while concomitantly, IL-1alpha controls immunosurveillance of the arising malignant cells. Elucidation of the involvement of the IL-1 molecules in the malignant process will hopefully lead to the development of novel approaches for chemoprevention and immunotherapy.
01 Feb 2009
TL;DR: The results suggest that reducing the activity of IL-1β does, in fact, significantly increase progression-free survival (PFS) in these high-risk patients, and the trial is thoroughly encouraging because long-term use of anakinra is safe.
Abstract: The article by Lust et al1 published in this issue of Mayo Clinic Proceedings is the first study to address a purely cytokine-driven pathogenic mechanism in the progression from a premalignant state of multiple myeloma to active disease. The working hypothesis is that myeloma plasma cell-derived interleukin 1 (IL-1) β induces marrow stromal cells to produce large amounts of interleukin 6 (IL-6), thereby promoting the survival and expansion of the myeloma cells. The 47 patients with smoldering or indolent multiple myeloma (SMM/IMM) enrolled in the study were clearly at high risk of progression to full-blown multiple myeloma on the basis of well-established criteria.2 For reduction of IL-1β activity, the trial used anakinra, a recombinant form of the naturally occurring interleukin 1 receptor antagonist (IL-1Ra) that is used for the treatment of rheumatoid arthritis and autoinflammatory diseases.3 The results of the study by Lust et al suggest that reducing the activity of IL-1β does, in fact, significantly increase progression-free survival (PFS) in these high-risk patients. The trial is thoroughly encouraging because long-term use of anakinra is safe. The combination of anakinra plus a low dose of dexamethasone provided the best outcomes. There may be a hidden benefit of reducing IL-1β activity in these patients; IL-1β is a potent, proangiogenic cytokine,4 and, compared with thalidomide, anakinra is essentially free of toxic adverse effects. A National Institutes of Health trial of anakinra as an antiangiogenic therapy for patients with cutaneous melanoma is ongoing.
TL;DR: An overview of the failures and successes of cytokines as therapeutic targets is provided and the use of agents that specifically block the activity of a cytokine truly defines the role of that cytokine in disease or in an immunologic response.
TL;DR: The link between inflammation and salt intake likely includes p38 MAPK as hyperosmolar sodium chloride triggers phosphorylation of p38MAPK and stimulates gene expression and synthesis of proinflammatory cytokines.
Abstract: Although there is increasing clinical evidence that high salt intake contributes to cardiovascular events and deaths seemingly independent of hypertension, the molecular mechanism for increased atherogenesis remains unclear. Vessel wall inflammation secondary to proinflammatory cytokines is one mechanism for atherogenesis. The role of mitogen activated protein kinase (MAPK) p38 in cytokine production such as IL-1, TNF-alpha, and IL-8 are well established. The link between inflammation and salt intake likely includes p38 MAPK as hyperosmolar sodium chloride triggers phosphorylation of p38 MAPK and stimulates gene expression and synthesis of proinflammatory cytokines. Hence a possible link of high salt intake, inflammation, and atherogenesis may be one molecular mechanism for the association of high salt intake and cardiovascular events.
01 Jan 2009
TL;DR: It is shown that, despite stimulatory effects on isolated human mononuclear cells, MDP does not stimulate production of tumour necrosis factor‐α, interleukin‐1β or interleucin‐6 in a whole‐blood assay, but MDP retains synergistic effects on lipopolysaccharide‐induced cytokines in whole blood.
Abstract: Summary Muramyl dipeptide (MDP) is the minimal active fragment of peptidoglycan of the cell wall of Gram-positive bacteria, with potential beneficial effects as a vaccineadjuvant.PeptidoglycansandMDParerecognizedbytheintracellular receptor NOD2 (nucleotide-binding oligomerization domain 2), leading to production of proinflammatory cytokines. In the present study, it is shown that, despite stimulatory effects on isolated human mononuclear cells, MDP does not stimulate production of tumour necrosis factor-a, interleukin-1b or interleukin-6inawhole-bloodassay.However,MDPretainssynergisticeffects on lipopolysaccharide-induced cytokines in whole blood. Screening tests of NOD2 function based on whole-blood stimulation should therefore employ strategies based on the synergistic effects of MDP on Toll-like receptor- inducedcytokineproduction.Plasmawasnotresponsiblefortheinhibitionof MDP in whole blood. The inhibition of MDP stimulation was dependent upon cellular components, with erythrocyte-derived haemoglobin and neu- trophils collaborating in the inhibition of MDP effects in whole blood.