Protein phosphorylations, mediated by pro-inflammatory cytokines IL-32g and IL-17A/F
ABSTRACT: Global kinase activity induced by cytokines IL-32g and IL-17A/F were determined using peptide arrays representing phophorylation targets The objective of this study was to identify common and unique phosphorylation targets of pro-inflammatory cytokines IL-32 and IL-17. These cytokines are associated with the pathogenesis and severity of chronic inflammatory disorders, therefore signaling intermediates of these cytokines could be beneficial as alternate theraputic targets that may likely influence different inflammatory pathways. Phosphorylation of proteins is a critical mechanism in the regulation of cellular processes. This process is meticulously regulated by enzymes known as kinases, which are increasingly being identified as drug targets for a variety of diseases. In this study we interrogated kinase activities (kinome) induced in the presence of the human recombinant cytokines IL-32g and IL-17A/F employing peptide arrays representing 300 peptides, printed in triplicate, representing select phosphorylation events. Human macrophage-like THP-1 cells were used for this comparative kinome analysis. Macrophage-like THP-1 cells were stimulated with either IL-32g (20 ng/ml) or IL-17A/F (20 ng/ml) for 15 min, and the peptide arrays were used to comprehensively analyze protein phosphorylation profiles in the presence of these cytokines. Two independet biological experiments were performed and the kinoem analysis was done in triplicates for each. The phosphorylations of the peptides on the array were quantified in the cytokine-treated cells relative to the un-stimulated control cells. Differentially phosphorylated targets were defined as greater than 1.5 fold increase or decrease (p < 0.06) in phosphorylation compared to un-stimulated control cells.
Project description:Global kinase activity induced by cytokines IL-32g and IL-17A/F were determined using peptide arrays representing phophorylation targets The objective of this study was to identify common and unique phosphorylation targets of pro-inflammatory cytokines IL-32 and IL-17. These cytokines are associated with the pathogenesis and severity of chronic inflammatory disorders, therefore signaling intermediates of these cytokines could be beneficial as alternate theraputic targets that may likely influence different inflammatory pathways. Overall design: Phosphorylation of proteins is a critical mechanism in the regulation of cellular processes. This process is meticulously regulated by enzymes known as kinases, which are increasingly being identified as drug targets for a variety of diseases. In this study we interrogated kinase activities (kinome) induced in the presence of the human recombinant cytokines IL-32g and IL-17A/F employing peptide arrays representing 300 peptides, printed in triplicate, representing select phosphorylation events. Human macrophage-like THP-1 cells were used for this comparative kinome analysis. Macrophage-like THP-1 cells were stimulated with either IL-32g (20 ng/ml) or IL-17A/F (20 ng/ml) for 15 min, and the peptide arrays were used to comprehensively analyze protein phosphorylation profiles in the presence of these cytokines. Two independet biological experiments were performed and the kinoem analysis was done in triplicates for each. The phosphorylations of the peptides on the array were quantified in the cytokine-treated cells relative to the un-stimulated control cells. Differentially phosphorylated targets were defined as greater than 1.5 fold increase or decrease (p < 0.06) in phosphorylation compared to un-stimulated control cells.
Project description:In psoriasis lesions, a diverse mixture of cytokines is upregulated which influence each other generating a complex inflammatory situation. Although this is the case, the inhibition of Interleukin-17A (IL-17A) alone showed unprecedented clinical results in patients, indicating that IL-17A is a critical inducer of psoriasis pathogenesis. To elucidate IL-17A-driven keratinocyte-intrinsic signaling pathways, we treated monolayers of normal human epidermal keratinocytes in vitro with a mixture of 6 cytokines (IL-17A, TNF-a, IL-17C, IL-22, IL-36g and IFN-g) involved in psoriasis, to mimic the inflammatory milieu in psoriasis lesions. Microarray and gene set enrichment analysis revealed that this cytokine mixture induced similar gene expression changes with the previous transcriptome studies using psoriasis lesions. Importantly, we identified a set of IL-17A-regulated genes in keratinocytes, which recapitulate typical psoriasis genes exemplified by DEFB4A, S100A7, IL19 and CSF3, based on differences in the expression profiles of cells stimulated with 6 cytokines versus cells stimulated with only 5 cytokines lacking IL-17A. Furthermore a specific IL-17A-induced gene, NFKBIZ, which encodes IkappaB-zeta, a transcriptional regulator for NF-kappaB, was demonstrated to have a significant role for IL-17A-induced gene expression. Thus, we present novel in vitro data from normal human keratinocytes that would help elucidating the IL-17A-driven keratinocyte activation in psoriasis. Cytokine mixture-induced gene expression in primary normal human epidermal keratinocytes (NHEKs) was measured at 24 hours after exposure. NHEKs were exposed to the combination of selected six cytokines (IL-17A: 100 ng/ml, TNF-a: 10 ng/ml, IFN-g: 10 ng/ml, IL-17C: 100 ng/ml, IL-22: 100 ng/ml, IL-36g: 500 ng/ml) , or to the different combinations of five of the six cytokines (in total, 7 different treatments and one untreated control). No replicate experiments were conducted.
Project description:IL-17A and IL-22 induced several inflammation-induced genes and anti-microbial molecules including Pla2g2a and Lcn2 on HepG2 cells when the cells were treated with the cytokines before Listeria monocytogenes infection. HepG2 cells were treated with 50 ng/ml IL-17A and 10 ng/ml IL-22 before L. monocytogenes in vitro infection at MOI 10. Reference cells were not treated with the cytokines before the infection. Two independent experiments were carried out.
Project description:Background:Hepatic ischemia and reperfusion (I/R) is common in liver surgery and transplantation and compromises postoperative liver function. Hepatic I/R injury is characterized by sterile inflammation that contributes to hepatocellular necrosis. Many immune cells and cytokines have been implicated in hepatic I/R injury. However, the role and relevance of IL-23 and IL-17A remains controversial in literature. Aim: To determine whether the IL-23/IL-17A signaling axis is activated in hepatic I/R using a triple-level experimental approach (in vitro, in vivo, and clinical). Methods:IL-23 and IL-17A were assayed by ELISA in the supernatant fractions of cultured murine (RAW 264.7) macrophages that were activated by supernatant fractions of necrotic cultured mouse (AML12) hepatocytes. Similarly, levels of these cytokines were determined in plasma samples and liver tissue of mice (N = 85) subjected to partial (70%) liver I/R. Finally, IL-23 and IL-17A were assayed in plasma samples obtained from a controlled cohort of liver resection patients who were either subjected to I/R (N = 27) or not (N = 13). Results:Activated macrophages did not produce IL-23 in response to supernatant of necrotic AML12 hepatocytes. IL-23 and IL-17A were not elevated in mice subjected hepatic I/R and were not elevated in serum from patients subjected to I/R during liver resection. Conclusion:IL-23 and IL-17A are not involved in hepatic I/R injury in mouse and man. Relevance for patients:If IL-23 and IL-17A were to mediate hepatocellular injury following I/R, these cytokines would constitute potential therapeutic targets. Since this study has revealed that IL-23 and IL-17A do not play a role in hepatic I/R, other pathways and therapeutic targets should be considered when developing modalities aimed at reducing hepatic I/R injury.
Project description:Pro-inflammatory IL-17 cytokines were initially described for their pathogenic role in chronic inflammatory diseases and subsequent accumulating evidence indicated their involvement in carcinogenesis. In the present study we report that IL-17A and IL-17E receptors subunits mRNA expressions are upregulated in breast cancers versus normal samples. IL-17E, which is undetectable in most normal breast tissues tested, seems more expressed in some tumors. Investigation of the molecular signaling following stimulation of human breast cancer cell lines with IL-17A and IL-17E showed that both cytokines induced the phosphorylation of c-RAF, ERK1/2 and p70 S6 Kinase were involved in the proliferation and survival of tumor cells. Accordingly, IL-17A and IL-17E promoted resistance to Docetaxel and failed to induce apoptosis as previously reported for IL-17E. Interestingly, we also revealed that both cytokines induced the generation of tumorogenic low molecular weight forms of cyclin E (LMW-E), which high levels correlated strongly with a poor survival in breast cancer patients. These results show for the first time some of the molecular pathways activated by IL-17A and IL-17E that may participate to their pro-oncogenic activity in breast cancers.
Project description:The cytokines TNF-? and IL-17A are elevated in a variety of autoimmune diseases, including rheumatoid arthritis. Both cytokines are targets of several biologic drugs used in the clinic, but unfortunately many patients are refractory to these therapies. IL-17A and TNF-? are known to mediate signaling synergistically to drive expression of inflammatory genes. Hence, combined blockade of TNF-? and IL-17A represents an attractive treatment strategy in autoimmune settings where monotherapy is not fully effective. However, a major concern with this approach is the potential predisposition to opportunistic infections that might outweigh any clinical benefits. Accordingly, we examined the impact of individual versus combined neutralization of TNF-? and IL-17A in a mouse model of rheumatoid arthritis (collagen-induced arthritis) and the concomitant susceptibility to infections that are likely to manifest as side effects of blocking these cytokines (oral candidiasis or tuberculosis). Our findings indicate that combined neutralization of TNF-? and IL-17A was considerably more effective than monotherapy in improving collagen-induced arthritis disease even when administered at a minimally efficacious dose. Encouragingly, however, dual cytokine blockade did not cooperatively impair antimicrobial host defenses, as mice given combined IL-17A and TNF-? neutralization displayed infectious profiles and humoral responses comparable to mice given high doses of individual anti-TNF-? or anti-IL-17A mAbs. These data support the idea that combined neutralization of TNF-? and IL-17A for refractory autoimmunity is likely to be associated with acceptable and manageable risks of opportunistic infections associated with these cytokines.
Project description:Maintenance of regulatory T cells CD4+CD25highFOXP3+ (Treg) stability is vital for proper Treg function and controlling the immune equilibrium. Treg cells are heterogeneous and can reveal plasticity, exemplified by their potential to express IL-17A. TNF?-TNFR2 signaling controls IL-17A expression in conventional T cells via the anti-inflammatory ubiquitin-editing and kinase activity regulating enzyme TNFAIP3/A20 (tumor necrosis factor-alpha-induced protein 3). To obtain a molecular understanding of TNF? signaling on IL-17 expression in the human effector (effTreg, CD25highCD45RA-) Treg subset, we here studied the kinome activity regulation by TNF? signaling. Using FACS-sorted naïve (naïveTreg, CD25highCD45RA+) and effTreg subsets, we demonstrated a reciprocal relationship between TNF? and IL-17A expression; effTreg (TNF?low/IL-17Ahigh) and naïveTreg (TNF?high/IL-17Alow). In effTreg, TNF?-TNFR2 signaling prevented IL-17A expression, whereas inhibition of TNF? signaling by clinically applied anti-TNF antibodies led to increased IL-17A expression. Inhibition of TNF? signaling led to reduced TNFAIP3 expression, which, by using siRNA inhibition of TNFAIP3, appeared causally linked to increased IL-17A expression in effTreg. Kinome activity screening of CD3/CD28-activated effTreg revealed that anti-TNF-mediated neutralization led to increased kinase activity. STRING association analysis revealed that the TNF suppression effTreg kinase activity network was strongly associated with kinases involved in TCR, JAK, MAPK, and PKC pathway signaling. Small-molecule-based inhibition of TCR and JAK pathways prevented the IL-17 expression in effTreg. Together, these findings stress the importance of TNF-TNFR2 in regulating the kinase architecture of antigen-activated effTreg and controlling IL-17 expression of the human Treg. These findings might be relevant for optimizing anti-TNF-based therapy and may aid in preventing Treg plasticity in case of Treg-based cell therapy.
Project description:Interleukin (IL)-17 plays an important and protective role in host defence and has been demonstrated to orchestrate airway inflammation by cooperating with and inducing proinflammatory cytokines. Mircoarrays were used to identify immediate-early/ primary response IL-17A-dependent gene transcripts in primary human bronchial ASM cells from mild asthmatic and healthy individuals. To evaluate IL-17A-inducible gene transcripts, primary human bronchial ASM cells from 3 mild asthmatic and 3 healthy donors were treated for 2h with IL-17 [10ng/ml] and were probed with the Affymetrix GeneChip array. The 2h time point was carefully chosen in order to identify primary response gene targets and to avoid confounding autocrine mechanisms mediating indirect, or late-phase gene expression responses. Non-stimulated ASM cells from the same patients were used as controls.
Project description:Junctional adhesion molecule-A (JAM-A), an epithelial tight junction protein, plays an important role in regulating intestinal permeability through association with a scaffold signaling complex containing ZO-2, Afadin, and the small GTPase Rap2. Under inflammatory conditions, we report that the cytoplasmic tail of JAM-A is tyrosine phosphorylated (p-Y280) in association with loss of barrier function. While barely detectable Y280 phosphorylation was observed in confluent monolayers of human intestinal epithelial cells under basal conditions, exposure to cytokines TNFα, IFNγ, IL-22, or IL-17A, resulted in compromised barrier function in parallel with increased p-Y280. Phosphorylation was Src kinase dependent, and we identified Yes-1 and PTPN13 as a major kinase and phosphatase for p-JAM-A Y280, respectively. Moreover, cytokines IL-22 or IL-17A induced increased activity of Yes-1. Furthermore, the Src kinase inhibitor PP2 rescued cytokine-induced epithelial barrier defects and inhibited phosphorylation of JAM-A Y280 in vitro. Phosphorylation of JAM-A Y280 and increased permeability correlated with reduced JAM-A association with active Rap2. Finally, we observed increased phosphorylation of Y280 in colonic epithelium of individuals with ulcerative colitis and in mice with experimentally induced colitis. These findings support a novel mechanism by which tyrosine phosphorylation of JAM-A Y280 regulates epithelial barrier function during inflammation.
Project description:Functional cytokine networks have been poorly characterized in systemic sclerosis (SSc). While interleukin-17A (IL-17A) is increased in SSc skin and other organs, its role is still debated, particularly considering fibrogenesis. We uncover here a dual function of IL-17A in the presence of transforming growth factor-? 1 (TGF-?), the master pro-fibrotic cytokine. In the one hand, we report an unexpected synergic activity resulting in enhanced production of IL-6 by dermal fibroblasts; in the other hand, a substantial inhibition of type I collagen (col-I) production. IL-17A or TGF-? enhanced the production of IL-6 by 8- to 16-folds when compared to control in healthy donors (HD) and SSc cultures. However, the joint presence of IL-17A and TGF-? resulted in robustly exuberant responses with levels of IL-6 up to 100-folds higher than those observed in untreated cells. Inhibition of NF?B signaling pathway preferentially inhibited the production of IL-6 driven by IL-17A in HD fibroblasts, while inhibition of PI3K preferentially inhibited the production of IL-6 driven by TGF-?. Interestingly, when p38 MAPK was inhibited, substantial reduction of IL-6 production was observed for both IL-17A and TGF-?. Consistently with the inhibition experiments, the combined stimulation of fibroblasts by IL-17A and TGF-? resulted in 1.8-fold increase in p38 MAPK phosphorylation (P?=?0.025), when compared to levels of phosphorylated p38 MAPK induced by IL-17A alone. Furthermore, the enhanced phosphorylation of p38 MAPK in the joint presence of IL-17A and TGF-? was unique among the signaling molecules we examined. As expected, TGF-? induced SMAD2 phosphorylation and col-I production. However, in fibroblasts cultured in the joint presence of TGF-? and IL-17A, SMAD2 phosphorylation was decreased by 0.6-folds (P?=?0.022) when compared to that induced by TGF-? alone. Remarkably, in this condition, the production of col-I and fibronectin was significantly decreased in both HD and SSc. Thus, IL-17A and TGF-? reciprocally influence each other effector functions in fibroblasts. Intracellular molecular switches may favor synergic or antagonistic activities, which are revealed by specific readouts. The implications of these data in the context of SSc are far reaching, particularly in terms of therapeutic approaches since IL-6, IL-17A, and TGF-? are all putative targets of treatment.