Systemic autoimmunity and lymphoproliferation are associated with excess IL-7 and inhibited by IL-7Rα blockade

Lupus is characterized by disturbances in lymphocyte homeostasis, as demonstrated by the marked accumulation of activated/memory T cells. Here, we provide evidence that proliferation of the CD8⁺ precursors for the accumulating CD4^–CD8^– T cells in MRL-Fas^lpr lupus-predisposed mice is, in part, driven by commensal antigens. The ensuing lymphadenopathy is associated with increased production of IL-7 due to expansion of fibroblastic reticular cells, the primary source of this cytokine. The excess IL-7 is not, however, consumed by CD4^–CD8^– T cells due to permanent down-regulation of IL-7Rα (CD127), but instead supports proliferation of autoreactive T cells and progression of autoimmunity. Accordingly, IL-7R blockade reduced T cell activation and autoimmune manifestations even when applied at advanced disease stage. These findings indicate that an imbalance favoring production over consumption of IL-7 may contribute to systemic autoimmunity, and correction of this imbalance may be a novel therapeutic approach in lymphoproliferative and autoimmune syndromes.     

Microparticulate P2X7 and GSDM-D mediated regulation of functional IL-1β release

Purinergic Signalling - The pro-inflammatory cytokine IL-1β is a secreted protein that is cleaved by caspase-1 during inflammasome activation upon recognition of internal and external insults...     

The additional value of TGFβ1 and IL-7 to predict the course of prostate cancer progression

Background

Given the fact that prostate cancer incidence will increase in the coming years, new prognostic biomarkers are needed with regard to the biological aggressiveness of the prostate cancer diagnosed. Since cytokines have been associated with the biology of cancer and its prognosis, we determined whether transforming growth factor beta 1 (TGFβ1), interleukin-7 (IL-7) receptor and IL-7 levels add additional prognostic information with regard to prostate cancer-specific survival.

Materials and methods

Retrospective survival analysis of forty-four prostate cancer patients, that underwent radical prostatectomy, was performed (1989–2001). Age, Gleason score and pre-treatment PSA levels were collected. IL-7, IL-7 receptor and TGFβ1 levels in prostate cancer tissue were determined by quantitative real-time RT-PCR and their additional prognostic value analyzed with regard to prostate cancer survival. Hazard ratios and their confidence intervals were estimated, and Akaike’s information criterion was calculated for model comparison.

Results

The predictive ability of a model for prostate cancer survival more than doubled when TGFβ1 and IL-7 were added to a model containing only the Gleason score and pre-treatment PSA (AIC: 18.1 and AIC: 6.5, respectively).

Conclusion

IL-7 and TGFβ1 are promising markers to indicate those at risk for poor prostate cancer survival. This additional information may be of interest with regard to the biological aggressiveness of the diagnosed prostate cancer, especially for those patients screened for prostate cancer and their considered therapy.     

Brain IL-6- and PG-dependent actions of IL-1β and lipopolysaccharide in avian fever

There is no persuasive evidence of a correlation between proinflammatory cytokines and avian fever. In this study, for the first time, we use avian cytokines to investigate a role for proinflammatory cytokines in the central component of avian fever. IL-1β and IL-6 injected intracerebroventricularly into Pekin ducks (n = 8) initiated robust fevers of equal magnitude and duration, although there was a significant difference in the latency to a febrile response. In addition, the IL-1β-induced fever could be abolished with an intracerebroventricular injection of antibodies to avian IL-6 or an oral administration of a PG synthesis inhibitor. Our findings indicate the following sequence of events within the central component of the avian febrile mechanism: IL-1β gives rise to bioactive IL-6, which stimulates an accelerated synthesis of PGs, and these PGs then adjust the sensitivity of warm-sensitive neurons in the avian brain stem to mediate fever. Yet PGE? was not upregulated in the cerebrospinal fluid of ducks made febrile with LPS. We conclude that IL-1β and IL-6 may well mediate fever by instigating an accelerated synthesis of brain-derived PG, of a class other than PGE?, or that IL-6 serves as one of the terminal mediators of the avian febrile response.     

Synthesis and stereochemistry of 7β- and 7α-amino-, acetamido-, hemisuccinamido- and terephthalamido derivatives of testosterone

The reduction of 3-ethylenedioxy-7-oximino-5-androsten-17β-yl acetate and of its 17β-tetrahydropyranyl ether analog with sodium in ethanol, followed by thin-layer chromatography, allowed the isolation of the corresponding 17β-hydroxy- and 17β-tetrahydropyranyioxy-5-en-7β- and 7α-amines which were also characte-rized as 7-acetamides. The acylation of the two epimeric 17β-hydroxy-5-en-7-amines with succinic anhydride followed by selective saponification of the 17β-hemisuccinate group and diazomethane esterification, gave the corresponding 17β-hydroxy-5-en-7β- and 7α-hemisuccinamido methyl esters characterized also as 17β-acetates. On the other hand, the acylation of the two 17β-tetrahydropyranyl-oxy-5-en-7-amines with the acid chloride of terephthalic acid monomethyi ester led to the more rigid 7β- and 7α-terephthalamido methyl ester side-chains. The acidolysis of the 3-ethyleneketal protecting group of the preceding 5-en-7-N-acyl derivatives regenerated the 4-en-3-oxo function while the 17β-tetrahydropyranyl ether group was cleaved simultaneously into the 17β-alcohol. The four desired 7β- and 7α-hemisuccinamido- and terephthalamido carboxylic side-chain derivatives of 17β-hydroxy-4-androsten-3-one (testosterone) were finally obtained by saponification of the corresponding methyl esters.     

Suppression of TNF-α and IL-1 signaling identifies a mechanism of homeostatic regulation of macrophages by IL-27

IL-27 is a pleiotropic cytokine with both activating and inhibitory functions on innate and acquired immunity. IL-27 is expressed at sites of inflammation in cytokine-driven autoimmune/inflammatory diseases, such as rheumatoid arthritis, psoriasis, inflammatory bowel disease, and sarcoidosis. However, its role in modulating disease pathogenesis is still unknown. In this study, we found that IL-27 production is induced by TNF-α in human macrophages (MΦ) and investigated the effects of IL-27 on the responses of primary human MΦ to the endogenous inflammatory cytokines TNF-α and IL-1. In striking contrast to IL-27-mediated augmentation of TLR-induced cytokine production, we found that IL-27 suppressed MΦ responses to TNF-α and IL-1β, thus identifying an anti-inflammatory function of IL-27. IL-27 blocked the proximal steps of TNF-α signaling by downregulating cell-surface expression of the signaling receptors p55 and p75. The mechanism of inhibition of IL-1 signaling was downregulation of the ligand-binding IL-1RI concomitant with increased expression of the receptor antagonist IL-1Ra and the decoy receptor IL-1RII. These findings provide a mechanism for suppressive effects of IL-27 on innate immune cells and suggest that IL-27 regulates inflammation by limiting activation of MΦ by inflammatory cytokines while preserving initial steps in host defense by augmenting responses to microbial products.     

Effect of cytokines (IL-2, IL-7, and IL-15) having common γ-chain of receptors on differentiation and maturation of CD4+/CD8+ T-cells in a CD45RA T-lymphocyte population in vitro

The effect of cytokines (IL-2, IL-7, and IL-15) having a common γ-chain of receptors on the maturation and differentiation of CD3⁺CD45RA⁺CD4⁺/CD8⁺ lymphocytes in homeostatic cultivation model in vitro was analyzed. It was found that the maximum IL-2 concentration in the helper CD45RA⁺-T-cell population mediates an increase in the number of CD45RA⁺CD4⁺ T lymphocytes with the phenotype of mature and immature terminally differentiated TEMRA T cells. IL-15 leads to the production of lymphocytes with CD27^–CD62L⁺ phenotype (presumably, TEMRA, in which the CD62L expression persists). In the CD45RA⁺CD8⁺ T lymphocyte populations, the studied cytokines (IL-2, IL-7, and IL-15) initiate the production of mature TEMRA (E) T lymphocytes and memory T cells with the CD45RA^?CD27⁺CD62L⁺ central phenotype (TCM).     

Lack of association or interactions between the IL-4, IL-4Rα and IL-13 genes, and rheumatoid arthritis

Introduction  

A feature of rheumatoid arthritis (RA) is an imbalance between proinflammatory and anti-inflammatory cytokines. Several recent studies have implicated polymorphism in the IL-4 signalling pathway in the development of erosive RA. The aim of the present study was to investigate the role of polymorphism in the IL-4, IL-4Rα and IL-13 genes in RA, including an examination of epistasis.     

IL-1α and IL-1β recruit different myeloid cells and promote different stages of sterile inflammation

The immune system has evolved to protect the host from invading pathogens and to maintain tissue homeostasis. Although the inflammatory process involving pathogens is well documented, the intrinsic compounds that initiate sterile inflammation and how its progression is mediated are still not clear. Because tissue injury is usually associated with ischemia and the accompanied hypoxia, the microenvironment of various pathologies involves anaerobic metabolites and products of necrotic cells. In the current study, we assessed in a comparative manner the role of IL-1α and IL-1β in the initiation and propagation of sterile inflammation induced by products of hypoxic cells. We found that following hypoxia, the precursor form of IL-1α, and not IL-1β, is upregulated and subsequently released from dying cells. Using an inflammation-monitoring system consisting of Matrigel mixed with supernatants of hypoxic cells, we noted accumulation of IL-1α in the initial phase, which correlated with the infiltration of neutrophils, and the expression of IL-1β correlated with later migration of macrophages. In addition, we were able to show that IL-1 molecules from cells transfected with either precursor IL-1α or mature IL-1β can recruit neutrophils or macrophages, respectively. Taken together, these data suggest that IL-1α, released from dying cells, initiates sterile inflammation by inducing recruitment of neutrophils, whereas IL-1β promotes the recruitment and retention of macrophages. Overall, our data provide new insight into the biology of IL-1 molecules as well as on the regulation of sterile inflammation.     

Modeling of the effects of IL-17 and TNF-α on endothelial cells and thrombus growth

Rheumatoid and psoriatic arthritis are chronic inflammatory diseases, with massive increase of cardiovascular events (CVE), and contribution of the cytokines TNF-α and IL-17. Chronic inflammation inside the joint membrane or synovium results from the activation of fibroblasts/synoviocytes, and leads to the release of cytokines from monocytes (Tumor Necrosis Factor or TNF) and from T lymphocytes (Interleukin-17 or IL-17). At the systemic level, the very same cytokines affect endothelial cells and vessel wall. We have previously shown [1], [2] that IL-17 and TNF-α, specifically when combined, increase procoagulation, decrease anticoagulation and increase platelet aggregation, leading to thrombosis. These results are the basis for the models of interactions between IL-17 and TNF, and genes expressed by activated endothelial cells. This work is devoted to mathematical modeling and numerical simulations of blood coagulation and clot growth under the influence of IL-17 and TNF-α. We show that they can provoke thrombosis, leading to the complete or partial occlusion of blood vessels. The regimes of blood coagulation and conditions of occlusion are investigated in numerical simulations and in approximate analytical models. The results of mathematical modeling allow us to predict thrombosis development for an individual patient.     

IL-1β, IL-6, and RANTES as Biomarkers of Chikungunya Severity

Background

Little is known about the immunopathogenesis of Chikungunya virus. Circulating levels of immune mediators and growth factors were analyzed from patients infected during the first Singaporean Chikungunya fever outbreak in early 2008 to establish biomarkers associated with infection and/or disease severity.

Methods and Findings

Adult patients with laboratory-confirmed Chikungunya fever infection, who were referred to the Communicable Disease Centre/Tan Tock Seng Hospital during the period from January to February 2008, were included in this retrospective study. Plasma fractions were analyzed using a multiplex-microbead immunoassay. Among the patients, the most common clinical features were fever (100%), arthralgia (90%), rash (50%) and conjunctivitis (40%). Profiles of 30 cytokines, chemokines, and growth factors were able to discriminate the clinical forms of Chikungunya from healthy controls, with patients classified as non-severe and severe disease. Levels of 8 plasma cytokines and 4 growth factors were significantly elevated. Statistical analysis showed that an increase in IL-1β, IL-6 and a decrease in RANTES were associated with disease severity.

Conclusions

This is the first comprehensive report on the production of cytokines, chemokines, and growth factors during acute Chikungunya virus infection. Using these biomarkers, we were able to distinguish between mild disease and more severe forms of Chikungunya fever, thus enabling the identification of patients with poor prognosis and monitoring of the disease.     

A new regulation of IL-6 production in adult cardiomyocytes by β-adrenergic and IL-1β receptors and induction of cellular hypertrophy by IL-6 trans-signalling

The sympathetic nervous system and pro-inflammatory cytokines play key roles in numerous cardiovascular disorders. Chronic β-adrenergic receptor (β-AR) stimulation in myocardium induces expression of pro-inflammatory cytokines, such as interleukin-1 (IL-1) and interleukin-6 (IL-6), which contribute to cardiac hypertrophy and failure. To evaluate the relationship between β-AR stimulation and pro-inflammatory cytokines, we studied the effects of the β-AR agonist isoprenaline (ISO) on IL-1-induced IL-6 production in adult rat ventricular myocytes (ARVMs). We report that ISO and IL-1 synergistically enhanced IL-6 gene expression and secretion. The synergistic effect of ISO was mimicked by cAMP elevating agents and involved the G_s protein/cAMP/PKA signalling pathway, but not the exchange factor EPAC. To evaluate the contribution of IL-6 to cellular hypertrophy, we examined the signalling pathways stimulated by the membrane-bound IL-6 receptor (IL-6R), and the IL-6 soluble receptor (sIL-6R) involved in the mechanism named IL-6 trans-signalling. The IL-6/sIL-6R complex promoted a rapid and persistent phosphorylation of STAT3^Tyr705 in ARVMs. Moreover, IL-6 trans-signalling increased protein synthesis, c-fos gene expression and B-type natriuretic peptide secretion, three markers of cardiac hypertrophy. IL-6 trans-signalling also increased cell size. In contrast, IL-6 alone had no significant effect on either cell size or STAT3 phosphorylation although it induced phosphorylation of ERK1/2, AKT and S6K, demonstrating the presence of a functional IL-6R in ARVMs. Taken together, these results demonstrate that β-AR stimulation synergises with IL-1 for IL-6 secretion in adult ventricular myocytes and indicate that IL-6 induces cardiac hypertrophy only via IL-6 trans-signalling. The IL-6 soluble receptor may thus serve as a switch for IL-6 to activate STAT3 phosphorylation and hypertrophy.     

B7-CD28 costimulatory signals control the survival and proliferation of murine and human γδ T cells via IL-2 production

γδ T cells play key nonredundant roles in immunity to infections and tumors. Thus, it is critical to understand the molecular mechanisms responsible for γδ T cell activation and expansion in vivo. In striking contrast to their αβ counterparts, the costimulation requirements of γδ T cells remain poorly understood. Having previously described a role for the TNFR superfamily member CD27, we since screened for other nonredundant costimulatory receptors in γδ T cell activation. We report in this article that the Ig superfamily receptor CD28 (but not its related protein ICOS) is expressed on freshly isolated lymphoid γδ T cells and synergizes with the TCR to induce autocrine IL-2 production that promotes γδ cell survival and proliferation in both mice and humans. Specific gain-of-function and loss-of-function experiments demonstrated a nonredundant function for CD28 interactions with its B7 ligands, B7.1 (CD80) and B7.2 (CD86), both in vitro and in vivo. Thus, γδ cell proliferation was significantly enhanced by CD28 receptor agonists but abrogated by B7 Ab-mediated blockade. Furthermore, γδ cell expansion following Plasmodium infection was severely impaired in mice genetically deficient for CD28. This resulted in the failure to mount both IFN-γ-mediated and IL-17-mediated γδ cell responses, which contrasted with the selective effect of CD27 on IFN-γ-producing γδ cells. Our data collectively show that CD28 signals are required for IL-2-mediated survival and proliferation of both CD27(+) and CD27(-) γδ T cell subsets, thus providing new mechanistic insight for their modulation in disease models.     

The 7th Editoral Board of Journal of Genetics and Genomics

Name Field of Research Interest Contact Address E-mail Address Advisor Shouyi Chen Plant molecular genetics Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China sychen@genetics.ac.cn Zhu Chen Medical genetics , Genomics Institute of Blood, Ruijin Hospital, Shanghai 200025 zchen@stn.sh.cn Jiayang Li Plant molecular genetics Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China jyli@geneti…     

Regulation of glycosyltransferases and Lewis antigens expression by IL-1β and IL-6 in human gastric cancer cells

Inflammation of stomach mucosa has been postulated as initiator of gastric carcinogenesis and the presence of pro-inflammatory cytokines can regulate specific genes involved in this process. The cellular expression pattern of glycosyltransferases and Lewis antigens detected in the normal mucosa changed during the neoplassic transformation. The aim of this work was to determine the regulation of specific fucosyltransferases and sialyltransferases by IL-1β and IL-6 pro-inflammatory cytokines in MKN45 gastric cancer cells. IL-1β induced significant increases in the mRNA levels of FUT1, FUT2 and FUT4, and decreases of FUT3 and FUT5. In IL-6 treatments, enhanced FUT1 and lower FUT3 and FUT5 mRNA expression were detected. No substantial changes were observed in the levels of ST3GalIII and ST3GalIV. The activation of FUT1, FUT2 and FUT4 by IL-1β is through the NF-κB pathway and the down-regulation of FUT3 and FUT5 by IL-6 is through the gp130/STAT-3 pathway, since they are inhibited specifically by panepoxydone and AG490, respectively. The levels of Lewis antigens after IL-1β or IL-6 stimulation decreased for sialyl-Lewis x, and no significant differences were found in the rest of the Lewis antigens analyzed, as it was also observed in subcutaneous mice tumors from MKN45 cells treated with IL-1β or IL-6. In addition, in 61 human intestinal-type gastric tumors, sialyl-Lewis x was highly detected in samples from patients that developed metastasis. These results indicate that the expression of the fucosyltransferases involved in the synthesis of Lewis antigens in gastric cancer cells can be specifically modulated by IL-1β and IL-6 inflammatory cytokines.     

Different Characteristics of Hepcidin Expression in IL-6+/+ and IL-6−/− Neurons and Astrocytes Treated with Lipopolysaccharides

A region-specific regulation of inflammation on the expression hepcidin in the brain has been demonstrated, however, it remains unknown whether there is also a cell-specific regulation of inflammation on hepcidin in the brain. Here, we investigated the effects of lipopolysaccharides (LPS) on the expression of hepcidin mRNA and also the expression of IL-6 mRNA, the phosphorylation of STAT3 and the expression of ferroportin 1 (Fpn1) and ferritin light chain (Ft-L) proteins in neurons and astrocytes obtained from wild type (IL-6+/+) and IL-6 knockout (IL-6?/?) mice. We demonstrated that the responses of the expression of hepcidin and IL-6 mRNAs, the phosphorylation of STAT3, and the expression of Fpn1 protein to LPS in IL-6+/+ astrocytes and also the responses of the expression of hepcidin mRNA, the phosphorylation of STAT3 and the expression of Fpn1 protein to IL-6 in IL-6?/? astrocytes were much stronger than those in IL-6+/+ and IL-6?/? neurons. A significant increase in Ft-L was found in LPS-treated IL-6+/+ and IL-6-treated IL-6?/? astrocytes, but not in LPS-treated IL-6+/+ and IL-6-treated IL-6?/? neurons. Our findings provide in vitro evidence for the existence of a cell-specific regulation of LPS on the expression of hepcidin and also Ft-L in the brain.     

Influence of Gangliosides on the IL-2– and IL-4–Dependent Cell Proliferation

Ganglioside-induced apoptosis in the cells of IL-2–dependent cytotoxic murine cell line CTLL-2 was shown to be caspase dependent: GM1-, GM2-, and GD3-induced suppression of cell proliferation was cancelled by a general caspase inhibitor Z-VAD-FMK. Ganglioside-induced apoptosis pathways are different for different individual glycolipids; the differences exist both at the initiation and effector stages of the caspase cascade. Only for GM1-induced process, molecular mechanisms of signal transduction coincide with the ones for CD95 and TNF: the participation of both the main initiation caspases 8, 1, and 4, and caspases 3 and 9 as well, has been shown. Caspase 3 participates in the pathway induced by GM3, GD1a, GD1b, and GT1b, but not by GM2. As morphological features show, tumor-associated ganglioside GM2 is also a stimulus of programmed cell death (PCD) for CTLL-2 cell line: addition of GM2 into cell culture has resulted in appearance of annexin V-positive cells and in accumulation of DNA breaks (shown by the TUNEL direct dyeing of the open ends). But a caspase 3 inhibitor Z-DEVD-FMK did not restore the cell proliferation suppressed by GM2, and addition of a fluorescent substrate of caspase 3 Ac-DEVD-AFC did not result in the fluorescence development. So caspase 3 does not participate in downstream pathways of GM2-induced cell apoptosis, and a PCD-effector system other than the apoptosome-mediated one is involved here.