Th17 cells favor inflammatory responses while inhibiting type I collagen deposition by dermal fibroblasts: differential effects in healthy and systemic sclerosis fibroblasts
- Nicolò Costantino Brembilla†1,
- Elisa Montanari†1,
- Marie-Elise Truchetet1,
- Elena Raschi2,
- Pierluigi Meroni2, 3 and
- Carlo Chizzolini1Email author
© Brembilla et al.; licensee BioMed Central Ltd. 2013
Received: 28 February 2013
Accepted: 25 September 2013
Published: 10 October 2013
T helper (Th)-17 cells are increased in systemic sclerosis (SSc). We therefore assessed whether Th17 cells could modulate the inflammatory and fibrotic responses in dermal fibroblasts from healthy donors (HD) and SSc individuals.
Fibroblasts were obtained from 14 SSc and 8 HD skin biopsies. Th17 clones were generated from healthy peripheral blood upon enrichment of CC chemokine receptor (CCR)-4/CCR6/CD161 expressing cells. Their cytokine production was assessed by flow cytometry and multiplex beads immunoassay. Fibroblast production of monocyte chemoattractant protein (MCP)-1, interleukin (IL)-8, matrix metalloproteinase (MMP)-1, tissue inhibitor of metalloproteinase (TIMP)-1, MMP-2 and type-I collagen was quantified by enzyme-linked immunosorbent assay (ELISA) and radioimmunoassay (RIA), and changes in their transcription levels assessed by real-time PCR. Intracellular signals were dissected by western blot and the use of pharmacological inhibitors. IL-17A, tumor necrosis factor (TNF) and interferon-gamma (IFN-γ) blocking reagents were used to assess the specificity of the observed effects.
IL-17A increased MCP-1, IL-8 and MMP-1 production in a dose-dependent manner while having no effect on type I collagen in HD and SSc fibroblasts both at protein and mRNA levels. Nuclear factor-kappa B (NF-κB) and p38 were preferentially involved in the induction of MCP-1 and IL-8, while MMP-1 was most dependent on c-Jun N-terminal kinase (JNK). Supernatants of activated Th17 clones largely enhanced MCP-1, IL-8 and MMP-1 while strongly inhibiting collagen production. Of note, the production of MCP-1 and IL-8 was higher, while collagen inhibition was lower in SSc compared to HD fibroblasts. The Th17 clone supernatant effects were mostly dependent on additive/synergistic activities between IL-17A, TNF and in part IFN-γ. Importantly, the inhibition of type I collagen production induced by the Th17 clone supernatants was completely abrogated by blockade of IL-17A, TNF and IFN-γ mostly in SSc fibroblasts, revealing an intrinsic resistance to inhibitory signals in SSc.
Our findings demonstrate that in vitro Th17 cells elicit pro-inflammatory responses while restraining collagen production. Thus, the increased Th17 cell number observed in SSc may impact on the inflammatory component of the disease simultaneously potentially providing a protective role against fibrosis.
Systemic sclerosis (SSc) is an autoimmune disorder of unknown origin characterized by fibro-proliferative microangiopathy and progressive fibrosis of the skin and internal organs [1, 2]. Fibrosis results from an overproduction of extracellular matrix (ECM) components by fibroblasts, especially type I collagen, accompanied by impaired ECM degradation. In early SSc, dermal fibroblasts display an inappropriate phenotype essentially characterized by increased proliferative potential, increased synthetic capacity, resistance to inhibitory signals and decreased apoptosis [1, 2]. In addition to collagens and matrix metalloproteinases (MMP), fibroblasts release several pro-inflammatory chemokines, such as monocytes chemoattractant protein (MCP)-1 and interleukin (IL)-8, which may indirectly influence ECM remodeling . Of interest, MCP-1 and IL-8 are increased in the skin and serum of SSc patients [4, 5] and appear to be critical in mediating bleomycin-induced lung and dermal fibrosis [6, 7].
The mechanisms leading to dysregulated activation of fibroblasts in SSc are only partially understood. T cells infiltrate SSc skin early and fibroblasts with high synthetic activity localize in close proximity to the inflammatory infiltrate (reviewed in ). T helper (Th) 2 polarized responses have been shown to be dominant in SSc skin and lung [9–13]. Consistently, IL-4 and IL-13 were shown to have direct pro-fibrotic activities on fibroblasts both in vitro and in vivo. In addition, we and others have reported that SSc individuals have increased Th17 cell counts in their peripheral blood and skin [15–21].
Th17 cells are physiologically implicated in protection against extracellular bacteria and fungi  and are thought to have pathogenic roles in various autoimmune diseases [23–25]. Th17 cells mainly produce IL-17A, in conjunction with IL-17 F, IL-21 and IL-22, and are enriched in the subset of T cells expressing the chemokine receptors CCR4 and CCR6 in the absence of CCR10 [26, 27]. They further express the lectin receptor CD161 . IL-17A has been shown to participate in the development of skin and lung fibrosis induced by bleomycin in mice [29, 30]. In agreement with a potential profibrotic role, IL-17 was shown to enhance fibroblast proliferation in humans , as well as their production of pro-inflammatory cytokines (MCP-1, IL-6 and IL-8) and matrix metalloproteinases (MMP-1 and MMP-3) [31, 32], and ICAM-1 expression . However, Kurasawa and colleagues could not show enhanced type I and type III procollagen mRNA expression in human fibroblasts cultured in the presence of IL-17 . Moreover, Nakashima et al. recently provided evidence for an anti-fibrotic effect of IL-17A in human fibroblasts via upregulation of miR-129-5p and downregulation of connective tissue growth factor and α1(I) collagen . In agreement with these findings, we observed that IL-17 decreased alpha-smooth muscle expression induced by transforming growth factor β (TGF-β) in human fibroblasts and that the number of IL-17A + cells in SSc skin correlated inversely with skin fibrosis . Thus, the role of Th17 cells in SSc remains uncertain. The aim of the present study was to investigate whether Th17 cells could promote phenotypic changes in dermal fibroblasts and compare fibroblast responses in healthy and SSc individuals. Our data highlight the direct role of Th17 cells in collagen inhibition accompanied by the simultaneous enhanced production of mediators of inflammation. Furthermore, the data stress the intrinsic resistance of SSc fibroblasts to inhibitory signals delivered by Th17 cells.
Fourteen SSc individuals (twelve women and two men) presenting at the Rheumatology Unit of the Gaetano Pini Hospital in Milan (Italy) or at the Immunology and Allergy department of the Geneva University Hospital (Switzerland) were prospectively included in the study. All patients met the American Rheumatism Association diagnostic criteria for SSc and were classified according to LeRoy et al. . None of the patients were under systemic immunosuppressive therapy apart from a low dose of glucocorticoids (<6 mg per day) at the time of sampling. Eight individuals had limited and six diffuse SSc. A biopsy was performed in the affected skin of the SSc individuals. The control group consisted of eight age and sex matched patients who underwent corrective breast or abdominal surgery at the department of plastic surgery of Clinique de La Tour in Geneva (Switzerland). None of the healthy individuals had dermatological disorders and none were under immunosuppressive agents or glucocorticoids. This study was approved by the ethical committee of the institutions involved (Comité departemental de médicine interne et médicine communautère des Hôpitaux Universitaires de Genève, Geneva, Switzerland; and the Institutional Review Board of the Istituto G. Pini, Milan, Italy) and was conducted according to the Declaration of Helsinki. Written informed consent was obtained from each individual.
Anti-CD3 (clone OKT3) monoclonal antibody (mAb) was from the American Tissue Culture Collection (Manassas, VA, USA); anti-CD4-APC-Cy7, anti-CD45RA-FITC, anti-CCR6-PerCP-Cy5.5, anti-CCR4-PE-Cy7, anti-CXCR3-APC, anti-CD161-APC and anti-CD28 mAbs from BD Biosciences (San Jose, CA, USA); anti-IL-4-APC, anti-IFN-γ-PE-Cy7 and anti-IL-17A-FITC, LEAF irrelevant control mAbs from Biolegend (San Diego, CA, USA); and anti-IL-22-PE, anti-CCR10-PE, recombinant human (rh) IL-23, TGF-β, tumor necrosis factor α (TNF), IL-17 and anti-human IL-17 Ab from R&D Systems (Abingdon, UK). Cytofix/Cytoperm fixation/permeabilization solution kit was from Becton Dickinson (San Diego, CA, USA); Ficoll-Paque Plus from GE Healthcare (Uppsala, Sweden); RPMI 1640, (Dulbecco’s) modified Eagle’s medium ((D)MEM), phosphate buffered saline (PBS), glutamine, penicillin, streptomycin, trypsin and fetal calf serum (FCS) from Gibco (Paisley, UK); phorbol myristate acetate (PMA), ß-mercaptoethanol, α-ketoglutaric acid, β-amino propionitrile, L-ascorbic acid, brefeldin A and nuclear factor-kappaB (NF-κB) peptide inhibitor TPCK from Sigma (St. Louis, MO, USA); rhIL-2 from Biogen (Cambridge, MA, USA); Dynal CD4 Negative Isolation kit from Invitrogen (Oslo, Norway) and phytohemagglutinin (PHA) from EY Laboratories (San Mateo, CA, USA). Radioimmunoassay (RIA) for type I procollagen (PINP-1) was from Orion Diagnostica (Espoo, Finland); and ionomycin, MEK1/2 pharmacological inhibitor U-0126, p38 inhibitor SB203580, JNK inhibitor SP-600125 and PI3K inhibitor LY294002 from Calbiochem (San Diego, CA, USA). TNFα soluble receptor p75 was a kind gift of Dr J Sims, Amgen, Seattle, WA, USA.
T cell cloning
CD4 + CD45RA- memory T cells (purity >99%) were isolated from healthy peripheral blood mononuclear cells (PBMC) by negative selection coupling the Dynal CD4 negative Isolation kit with anti-CD45RA mAb. The cells expressing CCR6 + CCR4 + CCR10- and CD161+ were stepwise positively sorted using FACSVantage (Becton Dickinson) to enrich for Th17 cells, resulting in a 7.8-fold enrichment of IL-17-producing CD4+ T cells compared to the parent population. The Th17-enriched cell strains were cloned by limiting dilution in the presence of 0.2 × 106 irradiated (3,500 Rad) allogeneic PBMC and 1 μg/ml PHA in complete RPMI supplemented with 20 U/ml IL-2 and 10 ng/ml of IL-23 as described . The T cell clones obtained were screened for IL-17A, IL-22 and IFN-γ production by intracellular fluorescence-activated cell sorting (FACS) analysis upon 4.5 hour PMA/Inomycin activation in the presence of brefeldin A with specific antibodies using FACSCanto (Becton Dickinson) flow cytometer and FlowJo software 7.5 (Tree Star, Ashland, OR, USA). Selected clones were activated or not by 1 μg/ml coated anti-CD3 and 1 μg/ml soluble CD28 antibodies and supernatants were harvested at 48 hours and frozen for further experiments.
Chemokine, cytokine and collagen assays
IL-22, MCP-1, MMP-1 and IL-8 were quantified in culture supernatants by ELISA (R&D for IL-22, MCP-1, MMP1; Invitrogen for IL-8). Collagen production was assessed by RIA quantification of PINP (Orion Diagnostica) according to the manufacturer’s instructions. IL-17A, IFN-γ, IL-4 and TNF were quantified by Luminex xMAPTM Technology using multiplex beads immunoassay (Fluorokine MAP Multiplex Human Cytokine Panel, R&D).
Real-time quantitative PCR
Total RNA was extracted from fibroblasts using an RNAesy micro kit (Qiagen, Hilden, Germany) and cDNA synthesized from 0.25 μg of total RNA using random hexamers and Superscript III reverse transcriptase (Invitrogen, Carlsbad, CA, USA) according to the manufacturer’s instructions. SYBR Green assays were performed on a SDS 7900 HT instrument (Applied Biosystems, Carlsbad, CA, USA). Each reaction was performed in triplicate. Raw cycle threshold (Ct) values obtained with SDS 2.2.2 software (Applied Biosystems) were analyzed and the more stable housekeeping genes (GAPDH (glyceraldehyde-3-phosphate dehydrogenase) and EEF1A1 (eukaryotic translation elongation factor 1 alpha 1)) selected for normalization. All oligonucleotides were obtained from Life Technologies (Carlsbad, CA, USA): CCL2 (F: AACCACAGTTCTACCCCTGGG; R:TAATGATTCTTGCAAAGACCCTCAA), IL8 (F:GCTCTCTTGGCAGCCTTCCT; R:TTAGCACTCCTTGGCAAAACTG), MMP1 (F: GGAGGAAAAGCAGCTCAAGAAC; R:TCCAGGGTGACACCAGTGACT), COL1A1 (F: CCCTCCTGACGCACGG; R:GTGATTGGTGGGATGTCTTCGT), COL1A2 (F:CTGTAAGAAAGGGCCCAGCC; R:GACCCCTTTCTCCACGTGG), MMP2 (F: CTCACAGAACCCTTGGAGCC; R:CCACCAGTGCCCTCTTGAGA), TIMP (F:CGTTATGAGATCAAGATGACCAAGAT; R:CCCCTAAGGCTTGGAACCC), IL-17RA (F:CCTGGAAGTGAAAAATACAGTGATGA; R:AGGCAGGCCATCGGTGT), IL-17RC (F:TGTGCAGTTTGGTCAGTCTGTG; R:GCCTCGAAGCAGTCATATACCAC), EEF1A1 (F: AGCAAAAATGACCCACCAATG; R:GGCCTGGATGGTTCAGGATA) and GAPDH (F: GCACAAGAGGAAGAGAGAGACC; R:AGGGGAGATTCAGTGTGGTG). Expression levels relative to the control condition were calculated using the ΔΔCt method.
Fibroblasts were lysed for 10 minutes on ice in pre-chilled radioimmunoprecipitation assay (RIPA) buffer supplemented with 5 mM ethylenediaminetetraacetic acid (EDTA), 50 mM NaF, 1 mM NasVO4, 100 mM okadaic acid, 1X Complete Protease Inhibitor Cocktail (Roche, Basel, Switzerland) and 0.2 mM phenylmethylsulfonyl fluoride (PMFS). Protein extracts were clarified by centrifugation and stored at -20°C until use. For western blot, 30 μg of total protein extract were separated in 10% SDS-PAGE, under reducing conditions, and electroblotted onto nitrocellulose membranes (AmershamTM HybondTM-ECL, GE Healthcare Zurich, Switzerland). Blots were incubated with antibodies against phospho-extracellular signal-regulated kinase (ERK)1/2 (Thr202/Tyr204), phospho-p38 (Thr180/Tyr182), phospho-c-Jun (Ser73), phospho-Smad2 (Ser465/467), IκB-α, phospho-IκB-α(Ser32), phospho-AKT (Ser473) (Cell Signaling, Danvers, MA, USA), phospho-c-Jun N-terminal kinases (JNK) (G-7) (Santa Cruz Biotechnology, Inc., Santa Cruz, CA, USA) and β-tubulin (Sigma). Horseradish peroxidase-conjugated antisera were used to reveal primary binding, followed by detection by an ECL system (GE Healthcare). Quantification analysis was performed with ImageJ software (http://rsbweb.nih.gov/ij) and values were normalized to β-tubulin.
Statistical analysis was performed with GraphPad Prism version 4.00 (Graphpad Software, La Jolla, CA, USA). Significant difference between samples was computed using Student’s t-test for paired or unpaired samples according to the experimental design. The Wilcoxon signed-rank test was used to compare fold changes in protein or mRNA levels relative to the control condition. A P value <0.05 was considered statistically significant.
IL-17A enhances MCP-1, IL-8 and MMP-1 but not type I collagen production in HD and SSc dermal fibroblasts
Consistently, IL-17A did not modify COL1A1 and COL1A2 mRNA levels both in SSc and HD fibroblasts (Figure 3A). Finally, IL-17A did not affect the mRNA levels of TIMP-1, and slightly, but significantly, enhanced MMP2 mRNA in SSc but not HD fibroblasts (Figure 3B).
Together, our findings demonstrate that IL-17A directly contributes to fibroblast inflammatory responses by enhancing MCP-1 and IL-8 production, and simultaneously impacts on ECM turnover by favoring MMP-1 rather than type I collagen production.
IL-17A effects on pro-inflammatory chemokines (MCP-1, IL-8) and MMP-1 are mediated by distinct signaling pathways
Th17 clones enhance MCP-1, IL-8 and MMP-1 and decrease type I collagen production to different extents in HD and SSc fibroblasts
Th17 cell supernatant effects are mainly mediated by IL-17A, TNF and, in part, IFN-γ
In the present report, we show that Th17 cells elicit MCP-1, IL-8 and MMP-1 responses while simultaneously inhibiting type I collagen production in healthy and SSc dermal fibroblasts. Our data are consistent with a model in which Th17 cells participate in inflammatory events but not directly in enhanced collagen deposition. In this perspective, Th17 cells may be seen as cells with an important role in limiting the development of fibrosis. In line with our data, a recent work by Nakashima et al. indicated that IL-17A may have direct anti-fibrotic effects in human normal fibroblasts via upregulation of miR-129-5p and downregulation of connective tissue growth factor and type I collagen . According to these authors, SSc fibroblasts may escape the negative control of IL-17A because of a reduced expression of the IL-17RA . In our experimental settings, diffuse SSc fibroblasts expressed increased IL-17RA mRNA levels but, in partial agreement with Nakashima et al., we observed that collagen production by SSc fibroblasts was more resistant to inhibition by Th17 cells. Additional in vivo evidence consistent with this model was obtained when we studied the number of IL-17A + cells in the skin of SSc individuals and found that the total skin thickness score was higher when IL-17A + dermal cells were less numerous . Of interest, Th17 cell numbers can be increased both in vitro and in vivo by iloprost, a PGI2 analog used in the clinical management of SSc digital ulcers, which may have beneficial effects on the disease course . These data and our model are distinctly different from data and conclusions generated in rodents, in which IL-17 was shown to favor in vivo collagen deposition in models of bleomycin-induced skin as well as lung fibrosis [29, 30, 40]. Furthermore, in the thigh skin of mice lacking IL-17 the spontaneous fibrotic skin was reduced , and finally IL-17 neutralization decreased lung inflammation and fibrosis induced by silica . The discrepancy between studies in humans and mice stresses species-specific differences in the responses induced by IL-17, as thoroughly discussed recently .
Our data clearly show that IL-17A directly promotes the production of pro-inflammatory mediators and MMP-1 by dermal fibroblasts from healthy and SSc individuals. Within the limits of the cohort investigated in this study, no differences were observed between limited and diffuse SSc individuals in this respect. These effects were largely amplified when supernatants from Th17 cell clones, producing high levels of IL-17, were assessed. Neutralizing experiments confirmed a critical role for IL-17A, at least in the case of IL-8, and revealed additive/synergic effects of IL-17 and TNF. Along this line of evidence, IL-17 was shown to enhance TNF-induced synthesis of IL-1, IL-6 and IL-8 by normal skin fibroblasts and osteoarthritis fibroblast-like synoviocytes . MCP-1 and IL-8 are increased in skin and serum of SSc patients [5, 43] and reported to be critical in mediating lung and dermal fibrosis in bleomycin-treated mice [6, 7]. However, whether these mediators have direct pro-fibrotic activities in humans is controversial. An increase in α1(I) collagen mRNA was reported by northern blot hybridization in human dermal fibroblasts activated by MCP-1 , while later reports could not confirm these findings . Similarly, MCP-1 was reported to increase the expression of MMP-1 and MMP-2, critical matrix degrading enzymes, but also the levels of their inhibitor TIMP-1 . The role of these mediators in tissue fibrosis observed in mice may be related more to chemoattractant and angiogenetic properties than to a direct pro-fibrotic activity on fibroblasts or to its role in favoring priming of Th2 cells [46, 47].
We found that IL-17A enhanced MMP-1 production in dermal fibroblasts, as previously reported in human cardiac fibroblasts and fibroblast-like synoviocytes [48–51]. MMPs participate in tissue remodeling, directly acting on ECM but also modulating the activity of many important mediators regulating matrix deposition . Despite its role as a degrading enzyme, MMP-1 levels have been paradoxically shown to be highly increased in human lung fibrosis , and variably reported to be increased, unchanged or decreased in SSc [54–57]. Thus, the exact role of MMP-1 in the development of fibrosis remains to be established.
We showed that IL-17A induced the production of pro-inflammatory chemokines preferentially via NF-κB and p38 signaling pathways, while inducing MMP-1 via JNK. Consistent with our data, IL-17 was previously shown to promote IL-6/IL-8 production via NF-κB/Akt and NF-κB/MAPK pathways in rheumatoid arthritis synovial fibroblasts and colonic myofibroblasts, respectively [58, 59] and in partial agreement with our findings, IL-17 induced MMP-1 production via activation of c-Fos/c-Jun AP1 and NF-κB in addition to MAPK signaling in cardiac fibroblasts .
Th17 cell clones were obtained after enrichment of cells expressing the chemokine receptor CCR6 and CCR4 in the absence of CCR10 [26, 27] and the lectin receptor CD161 . By applying this strategy, we obtained more than 70% of cells producing IL-17A. Compared to the expected numbers, the cloning procedure resulted in a slight enrichment of clones co-producing IL-17 and IFN-γ (Th1/Th17 cells), suggesting a relationship between the Th1 and Th17 differentiation programs. In line with these results, a functional plasticity connecting Th1 and Th17 cells was recently reported both in vitro and in vivo[28, 38, 60], although IL-17+/IFN-γ + cells were shown to have a transcription profile closer to Th17 than to Th1 cells .
Of note, SSc fibroblasts were more prone to produce pro-inflammatory mediators (MCP-1, IL-8) and less sensitive to collagen inhibition when cultured in the presence of Th17 cell clone supernatants than their healthy counterpart. This suggests that SSc fibroblasts may escape or limit the anti-fibrotic effects induced by Th17 cells, and further stresses the existence of intrinsic differences between normal and SSc fibroblasts. In this context, it is worth noting that the inhibition of type I collagen production induced by the Th17 clone supernatants was partially reversed by blockade of IL-17 or TNF mainly in HD but not SSc fibroblasts while IFN-γ neutralization had opposite effects. Again, the joint blockade of IL-17, TNF and IFN-γ resulted in maximal effects, specifically in SSc but not HD fibroblasts. In agreement with previous evidence [36, 61], the present data strongly suggest that, compared to normal fibroblasts, SSc fibroblasts are more resistant to inhibitory mediators present in the Th17 cell clone supernatants.
In conclusion, our data are consistent with a model in which Th17 cells may participate in enhancing inflammation while simultaneously limiting fibrosis. It is worth noting that the contribution of Th17 cells to inflammatory conditions remains in many instances a matter of debate. As an example, the role of IL-17 in the initiation, progression and stabilization of atherosclerosis is currently controversially interpreted with evidence in favor of its proatherogenic potential and evidence in favor of its atheroprotective role . Our findings stress for the first time the concomitant dual role of Th17 cells in the context of matrix deposition and may provide the functional basis for novel approaches to harness fibrotic diseases.
Th17 cells enhance in vitro fibroblast inflammatory responses while simultaneously inhibiting collagen production with a mechanism partially dependent on IL-17, TNF and IFN-γ. SSc fibroblasts are, however, intrinsically resistant to collagen inhibition induced by Th17 cells. Thus, the increased Th17 cell counts observed in SSc might be considered a manifestation of autoimmunity not mechanistically linked to fibrosis.
CC chemokine receptor
Diffuse systemic sclerosis
Enzyme-linked immunosorbent assay
Extracellular signal-regulated kinase
Fetal calf serum
c-Jun N-terminal kinases
Limited systemic sclerosis
Monocytes chemoattractant protein
MAP kinase kinase
Peripheral blood mononuclear cell
Transforming growth factor
Tissue inhibitor of metalloproteinase
Tumor necrosis factor.
The work was supported in part by grant 310030_140791 from the Swiss National Science Foundation and a grant from the “Association des Sclérodermiques de France” to CC. EM was supported by a grant from the Manodori Foundation, Reggio Emilia, Italy. PLM and ER were supported by a grant from Ricerca Corrente IRCCS Istituto Auxologico Italiano, Italy.
- Chizzolini C, Brembilla NC, Montanari E, Truchetet ME: Fibrosis and immune dysregulation in systemic sclerosis. Autoimmun Rev. 2011, 10: 276-281. 10.1016/j.autrev.2010.09.016.View ArticlePubMedGoogle Scholar
- Varga J, Abraham D: Systemic sclerosis: a prototypic multisystem fibrotic disorder. J Clin Invest. 2007, 117: 557-567. 10.1172/JCI31139.PubMed CentralView ArticlePubMedGoogle Scholar
- Hasegawa M, Sato S: The roles of chemokines in leukocyte recruitment and fibrosis in systemic sclerosis. Front Biosci. 2008, 13: 3637-3647.View ArticlePubMedGoogle Scholar
- Greenblatt MB, Sargent JL, Farina G, Tsang K, Lafyatis R, Glimcher LH, Whitfield ML, Aliprantis AO: Interspecies comparison of human and murine scleroderma reveals IL-13 and CCL2 as disease subset-specific targets. Am J Pathol. 2012, 180: 1080-1094. 10.1016/j.ajpath.2011.11.024.PubMed CentralView ArticlePubMedGoogle Scholar
- Yamamoto T, Eckes B, Hartmann K, Krieg T: Expression of monocyte chemoattractant protein-1 in the lesional skin of systemic sclerosis. J Dermatol Sci. 2001, 26: 133-139. 10.1016/S0923-1811(00)00169-9.View ArticlePubMedGoogle Scholar
- Ferreira AM, Takagawa S, Fresco R, Zhu X, Varga J, DiPietro LA: Diminished induction of skin fibrosis in mice with MCP-1 deficiency. J Invest Dermatol. 2006, 126: 1900-1908. 10.1038/sj.jid.5700302.View ArticlePubMedGoogle Scholar
- Keane MP, Arenberg DA, Lynch JP, Whyte RI, Iannettoni MD, Burdick MD, Wilke CA, Morris SB, Glass MC, DiGiovine B, Kunkel SL, Strieter RM: The CXC chemokines, IL-8 and IP-10, regulate angiogenic activity in idiopathic pulmonary fibrosis. J Immunol. 1997, 159: 1437-1443.PubMedGoogle Scholar
- Brembilla NC, Chizzolini C: T cell abnormalities in systemic sclerosis with a focus on Th17 cells. Eur Cytokine Netw. 2012, 23: 128-139.PubMedGoogle Scholar
- Atamas SP, Yurovsky VV, Wise R, Wigley FM, Goter Robinson CJ, Henry P, Alms WJ, White B: Production of type 2 cytokines by CD8+ lung cells is associated with greater decline in pulmonary function in patients with systemic sclerosis. Arthritis Rheum. 1999, 42: 1168-1178. 10.1002/1529-0131(199906)42:6<1168::AID-ANR13>3.0.CO;2-L.View ArticlePubMedGoogle Scholar
- Scaletti C, Vultaggio A, Bonifacio S, Emmi L, Torricelli F, Maggi E, Romagnani S, Piccinni MP: Th2-oriented profile of male offspring T cells present in women with systemic sclerosis and reactive with maternal major histocompatibility complex antigens. Arthritis Rheum. 2002, 46: 445-450. 10.1002/art.10049.View ArticlePubMedGoogle Scholar
- Parel Y, Aurrand-Lions M, Scheja A, Dayer JM, Roosnek E, Chizzolini C: Presence of CD4 + CD8+ double-positive T cells with very high interleukin-4 production potential in lesional skin of patients with systemic sclerosis. Arthritis Rheum. 2007, 56: 3459-3467. 10.1002/art.22927.View ArticlePubMedGoogle Scholar
- Fuschiotti P, Medsger TA, Morel PA: Effector CD8+ T cells in systemic sclerosis patients produce abnormally high levels of interleukin-13 associated with increased skin fibrosis. Arthritis Rheum. 2009, 60: 1119-1128. 10.1002/art.24432.View ArticlePubMedGoogle Scholar
- Medsger TA, Ivanco DE, Kardava L, Morel PA, Lucas MR, Fuschiotti P: GATA-3 up-regulation in CD8+ T cells as a biomarker of immune dysfunction in systemic sclerosis, resulting in excessive interleukin-13 production. Arthritis Rheum. 2011, 63: 1738-1747. 10.1002/art.30489.View ArticlePubMedGoogle Scholar
- Wynn TA: Cellular and molecular mechanisms of fibrosis. J Pathol. 2008, 214: 199-210. 10.1002/path.2277.PubMed CentralView ArticlePubMedGoogle Scholar
- Kurasawa K, Hirose K, Sano H, Endo H, Shinkai H, Nawata Y, Takabayashi K, Iwamoto I: Increased interleukin-17 production in patients with systemic sclerosis. Arthritis Rheum. 2000, 43: 2455-2463. 10.1002/1529-0131(200011)43:11<2455::AID-ANR12>3.0.CO;2-K.View ArticlePubMedGoogle Scholar
- Murata M, Fujimoto M, Matsushita T, Hamaguchi Y, Hasegawa M, Takehara K, Komura K, Sato S: Clinical association of serum interleukin-17 levels in systemic sclerosis: is systemic sclerosis a Th17 disease?. J Dermatol Sci. 2008, 50: 240-242. 10.1016/j.jdermsci.2008.01.001.View ArticlePubMedGoogle Scholar
- Radstake TR, van Bon L, Broen J, Hussiani A, Hesselstrand R, Wuttge DM, Deng Y, Simms R, Lubberts E, Lafyatis R: The pronounced Th17 profile in systemic sclerosis (SSc) together with intracellular expression of TGFbeta and IFNgamma distinguishes SSc phenotypes. PLoS One. 2009, 4: e5903-10.1371/journal.pone.0005903.PubMed CentralView ArticlePubMedGoogle Scholar
- Meloni F, Solari N, Cavagna L, Morosini M, Montecucco CM, Fietta AM: Frequency of Th1, Th2 and Th17 producing T lymphocytes in bronchoalveolar lavage of patients with systemic sclerosis. Clin Exp Rheumatol. 2009, 27: 765-772.PubMedGoogle Scholar
- Truchetet ME, Brembilla NC, Montanari E, Allanore Y, Chizzolini C: Increased frequency of circulating Th22 in addition to Th17 and Th2 lymphocytes in systemic sclerosis: association with interstitial lung disease. Arthritis Res Ther. 2011, 13: R166-10.1186/ar3486.PubMed CentralView ArticlePubMedGoogle Scholar
- Fenoglio D, Battaglia F, Parodi A, Stringara S, Negrini S, Panico N, Rizzi M, Kalli F, Conteduca G, Ghio M, De Palma R, Indiveri F, Filaci G: Alteration of Th17 and Treg cell subpopulations co-exist in patients affected with systemic sclerosis. Clin Immunol. 2011, 139: 249-257. 10.1016/j.clim.2011.01.013.View ArticlePubMedGoogle Scholar
- Rodriguez-Reyna TS, Furuzawa-Carballeda J, Cabiedes J, Fajardo-Hermosillo LD, Martinez-Reyes C, Diaz-Zamudio M, Llorente L: Th17 peripheral cells are increased in diffuse cutaneous systemic sclerosis compared with limited illness: a cross-sectional study. Rheumatol Int. 2011, 32: 2653-2660.View ArticlePubMedGoogle Scholar
- Korn T, Bettelli E, Oukka M, Kuchroo VK: IL-17 and Th17 Cells. Annu Rev Immunol. 2009, 27: 485-517. 10.1146/annurev.immunol.021908.132710.View ArticlePubMedGoogle Scholar
- Langrish CL, Chen Y, Blumenschein WM, Mattson J, Basham B, Sedgwick JD, McClanahan T, Kastelein RA, Cua DJ: IL-23 drives a pathogenic T cell population that induces autoimmune inflammation. J Exp Med. 2005, 201: 233-240. 10.1084/jem.20041257.PubMed CentralView ArticlePubMedGoogle Scholar
- Murphy CA, Langrish CL, Chen Y, Blumenschein W, McClanahan T, Kastelein RA, Sedgwick JD, Cua DJ: Divergent pro- and antiinflammatory roles for IL-23 and IL-12 in joint autoimmune inflammation. J Exp Med. 2003, 198: 1951-1957. 10.1084/jem.20030896.PubMed CentralView ArticlePubMedGoogle Scholar
- Yen D, Cheung J, Scheerens H, Poulet F, McClanahan T, McKenzie B, Kleinschek MA, Owyang A, Mattson J, Blumenschein W, Murphy E, Sathe M, Cua DJ, Kastelein RA, Rennick D: IL-23 is essential for T cell-mediated colitis and promotes inflammation via IL-17 and IL-6. J Clin Invest. 2006, 116: 1310-1316. 10.1172/JCI21404.PubMed CentralView ArticlePubMedGoogle Scholar
- Duhen T, Geiger R, Jarrossay D, Lanzavecchia A, Sallusto F: Production of interleukin 22 but not interleukin 17 by a subset of human skin-homing memory T cells. Nat Immunol. 2009, 10: 857-863. 10.1038/ni.1767.View ArticlePubMedGoogle Scholar
- Trifari S, Kaplan CD, Tran EH, Crellin NK, Spits H: Identification of a human helper T cell population that has abundant production of interleukin 22 and is distinct from T(H)-17, T(H)1 and T(H)2 cells. Nat Immunol. 2009, 10: 864-871. 10.1038/ni.1770.View ArticlePubMedGoogle Scholar
- Cosmi L, De Palma R, Santarlasci V, Maggi L, Capone M, Frosali F, Rodolico G, Querci V, Abbate G, Angeli R, Berrino L, Fambrini M, Caproni M, Tonelli F, Lazzeri E, Parronchi P, Liotta F, Maggi E, Romagnani S, Annunziato F: Human interleukin 17-producing cells originate from a CD161 + CD4+ T cell precursor. J Exp Med. 2008, 205: 1903-1916. 10.1084/jem.20080397.PubMed CentralView ArticlePubMedGoogle Scholar
- Wilson MS, Madala SK, Ramalingam TR, Gochuico BR, Rosas IO, Cheever AW, Wynn TA: Bleomycin and IL-1beta-mediated pulmonary fibrosis is IL-17A dependent. J Exp Med. 2010, 207: 535-552. 10.1084/jem.20092121.PubMed CentralView ArticlePubMedGoogle Scholar
- Okamoto Y, Hasegawa M, Matsushita T, Hamaguchi Y, Huu DL, Iwakura Y, Fujimoto M, Takehara K: Potential roles of interleukin 17A in the development of skin fibrosis. Arthritis Rheum. 2012, 64: 3726-3735. 10.1002/art.34643.View ArticlePubMedGoogle Scholar
- Agarwal S, Misra R, Aggarwal A: Interleukin 17 levels are increased in juvenile idiopathic arthritis synovial fluid and induce synovial fibroblasts to produce proinflammatory cytokines and matrix metalloproteinases. J Rheumatol. 2008, 35: 515-519.PubMedGoogle Scholar
- Fossiez F, Djossou O, Chomarat P, Flores-Romo L, Ait-Yahia S, Maat C, Pin JJ, Garrone P, Garcia E, Saeland S, Blanchard D, Gaillard C, Das Mahapatra B, Rouvier E, Golstein P, Banchereau J, Lebecque S: T cell interleukin-17 induces stromal cells to produce proinflammatory and hematopoietic cytokines. J Exp Med. 1996, 183: 2593-2603. 10.1084/jem.183.6.2593.View ArticlePubMedGoogle Scholar
- Nakashima T, Jinnin M, Yamane K, Honda N, Kajihara I, Makino T, Masuguchi S, Fukushima S, Okamoto Y, Hasegawa M, Fujimoto M, Ihn H: Impaired IL-17 signaling pathway contributes to the increased collagen expression in scleroderma fibroblasts. J Immunol. 2012, 188: 3573-3583. 10.4049/jimmunol.1100591.View ArticlePubMedGoogle Scholar
- Truchetet ME, Brembilla NC, Montanari E, Lonati P, Raschi E, Zeni S, Fontao L, Meroni PL, Chizzolini C: Interleukin-17A + cell counts are increased in systemic sclerosis skin and their number is inversely correlated with the extent of skin involvement. Arthritis Rheum. 2013, 65: 1347-1356. 10.1002/art.37860.View ArticlePubMedGoogle Scholar
- LeRoy EC, Black C, Fleischmajer R, Jablonska S, Krieg T, Medsger TA, Rowell N, Wollheim F: Scleroderma (systemic sclerosis): classification, subsets and pathogenesis. J Rheumatol. 1988, 15: 202-205.PubMedGoogle Scholar
- Chizzolini C, Parel Y, De Luca C, Tyndall A, Akesson A, Scheja A, Dayer JM: Systemic sclerosis Th2 cells inhibit collagen production by dermal fibroblasts via membrane-associated tumor necrosis factor alpha. Arthritis Rheum. 2003, 48: 2593-2604. 10.1002/art.11129.View ArticlePubMedGoogle Scholar
- Chizzolini C, Chicheportiche R, Alvarez M, de Rham C, Roux-Lombard P, Ferrari-Lacraz S, Dayer JM: Prostaglandin E2 synergistically with interleukin-23 favors human Th17 expansion. Blood. 2008, 112: 3696-3703. 10.1182/blood-2008-05-155408.PubMed CentralView ArticlePubMedGoogle Scholar
- Boniface K, Blumenschein WM, Brovont-Porth K, McGeachy MJ, Basham B, Desai B, Pierce R, McClanahan TK, Sadekova S, de Waal MR: Human Th17 cells comprise heterogeneous subsets including IFN-gamma-producing cells with distinct properties from the Th1 lineage. J Immunol. 2010, 185: 679-687. 10.4049/jimmunol.1000366.View ArticlePubMedGoogle Scholar
- Truchetet ME, Allanore Y, Montanari E, Chizzolini C, Brembilla NC: Prostaglandin I2 analogues enhance already exuberant Th17 cell responses in systemic sclerosis. Ann Rheum Dis. 2012, 71: 2044-2050. 10.1136/annrheumdis-2012-201400.View ArticlePubMedGoogle Scholar
- Yoshizaki A, Yanaba K, Ogawa A, Asano Y, Kadono T, Sato S: Immunization with DNA topoisomerase I and Freund's complete adjuvant induces skin and lung fibrosis and autoimmunity via interleukin-6 signaling. Arthritis Rheum. 2011, 63: 3575-3585. 10.1002/art.30539.View ArticlePubMedGoogle Scholar
- Mi S, Li Z, Yang HZ, Liu H, Wang JP, Ma YG, Wang XX, Liu HZ, Sun W, Hu ZW: Blocking IL-17A promotes the resolution of pulmonary inflammation and fibrosis via TGF-beta1-dependent and -independent mechanisms. J Immunol. 2011, 187: 3003-3014. 10.4049/jimmunol.1004081.View ArticlePubMedGoogle Scholar
- Katz Y, Nadiv O, Beer Y: Interleukin-17 enhances tumor necrosis factor alpha-induced synthesis of interleukins 1, 6, and 8 in skin and synovial fibroblasts: a possible role as a "fine-tuning cytokine" in inflammation processes. Arthritis Rheum. 2001, 44: 2176-2184. 10.1002/1529-0131(200109)44:9<2176::AID-ART371>3.0.CO;2-4.View ArticlePubMedGoogle Scholar
- Furuse S, Fujii H, Kaburagi Y, Fujimoto M, Hasegawa M, Takehara K, Sato S: Serum concentrations of the CXC chemokines interleukin 8 and growth-regulated oncogene-alpha are elevated in patients with systemic sclerosis. J Rheumatol. 2003, 30: 1524-1528.PubMedGoogle Scholar
- Distler JH, Jungel A, Caretto D, Schulze-Horsel U, Kowal-Bielecka O, Gay RE, Michel BA, Muller-Ladner U, Kalden JR, Gay S, Distler O: Monocyte chemoattractant protein 1 released from glycosaminoglycans mediates its profibrotic effects in systemic sclerosis via the release of interleukin-4 from T cells. Arthritis Rheum. 2006, 54: 214-225. 10.1002/art.21497.View ArticlePubMedGoogle Scholar
- Yamamoto T, Eckes B, Mauch C, Hartmann K, Krieg T: Monocyte chemoattractant protein-1 enhances gene expression and synthesis of matrix metalloproteinase-1 in human fibroblasts by an autocrine IL-1 alpha loop. J Immunol. 2000, 164: 6174-6179.View ArticlePubMedGoogle Scholar
- Gillitzer R, Goebeler M: Chemokines in cutaneous wound healing. J Leukoc Biol. 2001, 69: 513-521.PubMedGoogle Scholar
- Lukacs NW, Chensue SW, Karpus WJ, Lincoln P, Keefer C, Strieter RM, Kunkel SL: C-C chemokines differentially alter interleukin-4 production from lymphocytes. Am J Pathol. 1997, 150: 1861-1868.PubMed CentralPubMedGoogle Scholar
- Chabaud M, Garnero P, Dayer JM, Guerne PA, Fossiez F, Miossec P: Contribution of interleukin 17 to synovium matrix destruction in rheumatoid arthritis. Cytokine. 2000, 12: 1092-1099. 10.1006/cyto.2000.0681.View ArticlePubMedGoogle Scholar
- Cortez DM, Feldman MD, Mummidi S, Valente AJ, Steffensen B, Vincenti M, Barnes JL, Chandrasekar B: IL-17 stimulates MMP-1 expression in primary human cardiac fibroblasts via p38 MAPK- and ERK1/2-dependent C/EBP-beta, NF-kappaB, and AP-1 activation. Am J Physiol Heart Circ Physiol. 2007, 293: H3356-H3365. 10.1152/ajpheart.00928.2007.View ArticlePubMedGoogle Scholar
- Moran EM, Mullan R, McCormick J, Connolly M, Sullivan O, Fitzgerald O, Bresnihan B, Veale DJ, Fearon U: Human rheumatoid arthritis tissue production of IL-17A drives matrix and cartilage degradation: synergy with tumour necrosis factor-alpha, Oncostatin M and response to biologic therapies. Arthritis Res Ther. 2009, 11: R113-10.1186/ar2772.PubMed CentralView ArticlePubMedGoogle Scholar
- van Hamburg JP, Asmawidjaja PS, Davelaar N, Mus AM, Colin EM, Hazes JM, Dolhain RJ, Lubberts E: Th17 cells, but not Th1 cells, from patients with early rheumatoid arthritis are potent inducers of matrix metalloproteinases and proinflammatory cytokines upon synovial fibroblast interaction, including autocrine interleukin-17A production. Arthritis Rheum. 2011, 63: 73-83. 10.1002/art.30093.View ArticlePubMedGoogle Scholar
- Page-McCaw A, Ewald AJ, Werb Z: Matrix metalloproteinases and the regulation of tissue remodelling. Nat Rev Mol Cell Biol. 2007, 8: 221-233. 10.1038/nrm2125.PubMed CentralView ArticlePubMedGoogle Scholar
- Zuo F, Kaminski N, Eugui E, Allard J, Yakhini Z, Ben-Dor A, Lollini L, Morris D, Kim Y, DeLustro B, Sheppard D, Pardo A, Selman M, Heller RA: Gene expression analysis reveals matrilysin as a key regulator of pulmonary fibrosis in mice and humans. Proc Natl Acad Sci U S A. 2002, 99: 6292-6297. 10.1073/pnas.092134099.PubMed CentralView ArticlePubMedGoogle Scholar
- Kuroda K, Shinkai H: Gene expression of types I and III collagen, decorin, matrix metalloproteinases and tissue inhibitors of metalloproteinases in skin fibroblasts from patients with systemic sclerosis. Arch Dermatol Res. 1997, 289: 567-572. 10.1007/s004030050241.View ArticlePubMedGoogle Scholar
- Young-Min SA, Beeton C, Laughton R, Plumpton T, Bartram S, Murphy G, Black C, Cawston TE: Serum TIMP-1, TIMP-2, and MMP-1 in patients with systemic sclerosis, primary Raynaud's phenomenon, and in normal controls. Ann Rheum Dis. 2001, 60: 846-851.PubMed CentralView ArticlePubMedGoogle Scholar
- Toubi E, Kessel A, Grushko G, Sabo E, Rozenbaum M, Rosner I: The association of serum matrix metalloproteinases and their tissue inhibitor levels with scleroderma disease severity. Clin Exp Rheumatol. 2002, 20: 221-224.PubMedGoogle Scholar
- Frost J, Ramsay M, Mia R, Moosa L, Musenge E, Tikly M: Differential gene expression of MMP-1, TIMP-1 and HGF in clinically involved and uninvolved skin in South Africans with SSc. Rheumatology (Oxford). 2012, 51: 1049-1052. 10.1093/rheumatology/ker367.View ArticleGoogle Scholar
- Hata K, Andoh A, Shimada M, Fujino S, Bamba S, Araki Y, Okuno T, Fujiyama Y, Bamba T: IL-17 stimulates inflammatory responses via NF-kappaB and MAP kinase pathways in human colonic myofibroblasts. Am J Physiol Gastrointest Liver Physiol. 2002, 282: G1035-G1044.View ArticlePubMedGoogle Scholar
- Hwang SY, Kim JY, Kim KW, Park MK, Moon Y, Kim WU, Kim HY: IL-17 induces production of IL-6 and IL-8 in rheumatoid arthritis synovial fibroblasts via NF-kappaB- and PI3-kinase/Akt-dependent pathways. Arthritis Res Ther. 2004, 6: R120-R128. 10.1186/ar1038.PubMed CentralView ArticlePubMedGoogle Scholar
- Lee YK, Turner H, Maynard CL, Oliver JR, Chen D, Elson CO, Weaver CT: Late developmental plasticity in the T helper 17 lineage. Immunity. 2009, 30: 92-107. 10.1016/j.immuni.2008.11.005.PubMed CentralView ArticlePubMedGoogle Scholar
- Chizzolini C, Rezzonico R, Ribbens C, Burger D, Wollheim FA, Dayer JM: Inhibition of type I collagen production by dermal fibroblasts upon contact with activated T cells: different sensitivity to inhibition between systemic sclerosis and control fibroblasts. Arthritis Rheum. 1998, 41: 2039-2047. 10.1002/1529-0131(199811)41:11<2039::AID-ART20>3.0.CO;2-1.View ArticlePubMedGoogle Scholar
- Butcher M, Galkina E: Current views on the functions of interleukin-17A-producing cells in atherosclerosis. Thromb Haemost. 2011, 106: 787-795. 10.1160/TH11-05-0342.PubMed CentralView ArticlePubMedGoogle Scholar
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