The JI
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     
 

This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Boniface, K.
Right arrow Articles by Lecron, J.-C.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Boniface, K.
Right arrow Articles by Lecron, J.-C.
The Journal of Immunology, 2007, 178: 4615-4622.
Copyright © 2007 by The American Association of Immunologists, Inc.

Oncostatin M Secreted by Skin Infiltrating T Lymphocytes Is a Potent Keratinocyte Activator Involved in Skin Inflammation1

Katia Boniface2,*, Caroline Diveu2,{dagger},**, Franck Morel*, Nathalie Pedretti{ddagger}, Josy Froger{dagger},**, Elisa Ravon{dagger},**, Martine Garcia*, Emilie Venereau{dagger},**, Laurence Preisser{dagger},**, Emmanuel Guignouard*, Gérard Guillet*,§, Guy Dagregorio*,¶, Jérôme Pène||, Jean-Pierre Moles#, Hans Yssel||, Sylvie Chevalier{dagger},**, François-Xavier Bernard{ddagger}, Hugues Gascan3,{dagger},** and Jean-Claude Lecron3,*

* UPRES-EA 3806, Centre Hospitalier de l’Université de Poitiers, Poitiers, France; {dagger} Institut National de la Santé et de la Recherche Médicale, Unité Mixte 564, Angers, France; {ddagger} BIOalternatives, Gençay, France; § Service de Dermatologie, Centre Hospitalier de l’Université La Milétrie, Poitiers, France; Service de Chirurgie Plastique, Centre Hospitalier de l’Université La Milétrie, Poitiers, France; || Unité Mixte Institut National de la Santé et de la Recherche Médicale 454, Hôpital Arnaud de Villeneuve, Montpellier, France; and # Laboratoire de Dermatologie Moléculaire, Institut Universitaire de Recherche Clinique, Montpellier, France; ** Université d’Angers, Angers, France


   Abstract
Top
 Abstract
Introduction
 Materials and Methods
 Results
 Discussion
 Disclosures
 References
 
Cutaneous inflammatory diseases such as psoriasis vulgaris and atopic dermatitis are associated with altered keratinocyte function, as well as with a particular cytokine production profile of skin-infiltrating T lymphocytes. In this study we show that normal human epidermal keratinocytes express a functional type II oncostatin-M (OSM) receptor (OSMR) consisting of the gp130 and OSMRbeta components, but not the type I OSMR. The type II OSMR is expressed in skin lesions from both psoriatic patients and those with atopic dermatitis. Its ligand, OSM, induces via the recruitment of the STAT3 and MAP kinase pathways a gene expression profile in primary keratinocytes and in a reconstituted epidermis that is characteristic of proinflammatory and innate immune responses. Moreover, OSM is a potent stimulator of keratinocyte migration in vitro and increases the thickness of a reconstituted epidermis. OSM transcripts are enhanced in both psoriatic and atopic dermatitic skin as compared with healthy skin and mirror the enhanced production of OSM by T cells isolated from diseased lesions. Results from a microarray analysis comparing the gene-modulating effects of OSM with those of 33 different cytokines indicate that OSM is a potent keratinocyte activator similar to TNF-{alpha}, IL-1, IL-17, and IL-22 and that it acts in synergy with the latter cytokines in the induction of S100A7 and beta-defensin 2 expression, characteristic of psoriatic skin. Taken together, these results demonstrate that OSM and its receptor play an important role in cutaneous inflammatory responses in general and that the specific effects of OSM are associated with distinct inflammatory diseases depending on the cytokine environment.


   Introduction
Top
 Abstract
 Introduction
Materials and Methods
 Results
 Discussion
 Disclosures
 References
 
The skin is a large and complex tissue providing a protective interface between the organism and its environment. The epidermis forms the regenerating outer surface of the skin and consists of multiple layers of specialized epithelial cells, the keratinocytes. In response to stress or injury, keratinocytes release signaling molecules that modulate the expression of cell surface receptors and modify their cytoskeleton morphology, thereby altering their proliferative and migratory capacities. These changes are closely associated with an inflammatory response that leads to either wound healing or defense against microbial infection, and often leading to chronic disease. Among the most common inflammatory skin diseases in the Western population are psoriasis vulgaris and atopic dermatitis. Although the mechanisms underlying their pathogeneses are different, both disorders are associated with keratinocyte hyperplasia, proliferation, and altered differentiation as well as with the presence of increased numbers of T cells in the lesions secreting a wide variety of cytokines. It is generally accepted that immune responses in atopic dermatitis are associated with the activity of cytokines secreted by Th2 lymphocytes that contribute to the high IgE levels and eosinophilia characteristic of this condition. In contrast, the immune response in psoriasis is mediated by Th1 and most likely by Th17 cells (1) that secrete inflammatory cytokines and are furthermore associated with local neutrophil infiltration. Interestingly although both skin diseases are characterized by defective skin barriers, patients with atopic dermatitis, in contrast to those with psoriasis, suffer from frequent serious skin infections (2) that are associated with a particular gene expression profile in epidermal keratinocytes (3).

Oncostatin M (OSM)4 is a member of the IL-6 family of cytokines, which are multifunctional proteins involved in immunity, hemopoiesis, bone modeling, and inflammatory processes. Mainly secreted by activated T cells, monocytes, and dendritic cells, OSM is a proinflammatory mediator that strongly triggers acute phase protein synthesis by liver cells (4, 5). Many of its biological functions are also shared with the leukemia inhibitory factor (LIF), another IL-6 family member. These shared and specific functions of OSM are explained by the existence of two types of OSM receptor (OSMR) complexes. In addition to the common LIF/OSM type I receptor complex composed of the gp130 and LIF receptor beta (LIFRbeta) subunits, OSM also specifically recognizes a type II receptor in which the gp130 receptor chain is associated with the OSMR beta-chain (6, 7, 8). The OSM-induced signaling cascade involves activation of certain Janus kinases (JAK1, JAK2, and Tyk2) and signal transducers and activators of transcription (STAT1 and STAT3), as well as MAPK pathways (9). The OSMR beta subunit is mainly expressed by fibroblasts, endothelial, hepatic, lung, and hemopoietic cells, and it has been reported that OSMRbeta can be also recruited by IL-31, a recently identified cytokine with skin tropism (10).

In the present study we have determined the expression of both OSMR and OSM in the lesions of cutaneous inflammatory diseases and have investigated the effect of OSM on keratinocytes in vitro and in vivo by analyzing a gene expression profile specifically selected to study keratinocyte structure and function (11). We show that the expression of the type II, but not the type I OSMR, is enhanced in both psoriatic and atopic dermatitic lesions and that OSM-induced, STAT3-mediated keratinocyte alteration is associated with cutaneous inflammatory responses.


   Materials and Methods
Top
 Abstract
 Introduction
 Materials and Methods
Results
 Discussion
 Disclosures
 References
 
Cell culture

All of our studies involving human tissues were reviewed and approved by the institutional ethics committee on human experimentation "Comité Consultatif de Protection des Personnes dans la Recherche Biomédicale" of the Région Poitou-Charentes. Normal human epidermal keratinocytes (NHEK) were obtained and cultured as described previously (12). A keratinocyte migration assay was performed as described previously (13). In vitro reconstituted human epidermis (RHE) was purchased from SkinEthic Laboratories (14). Skin-infiltrating or peripheral blood T cells were expanded using Expander beads (Invitrogen Life Technologies) as described previously (15, 16). For cytokine production, 2 x 106 T cells/ml were activated with immobilized anti-CD3 mAb, anti-CD28 mAb, and IL-2 for 24 h and cytokine production was analyzed by ELISA.

Reagents

Cytokines were purchased from R&D Systems Anti-gp130 (AN-HH1, AN-HH2, AN-G30), anti-OSMRbeta (AN-N2, AN-R2, and AN-V2), and anti-LIFRbeta (AN-E1) mAbs were produced in the laboratory, and the neutralizing anti-OSMRbeta Ab (XR-M70) came from Immunex. Polyclonal anti-gp130, anti-LIFRbeta, anti-STAT3, anti-S100A8, and anti-S100A9 Abs were from Santa Cruz Biotechnology; anti-S100A7 and anti-beta-tubulin Abs were from Imgenex and Sigma-Aldrich, respectively; anti-phospho-STAT3, phospho-MAPK, and MAPK were from Upstate Biotechnology; goat anti-mouse and anti-rabbit peroxidase-labeled Ig were from CliniSciences; rabbit anti-goat peroxidase-conjugated Ab was from Sigma-Aldrich; and the anti-cytokeratin (CK) 10 and anti-filaggrin Abs were from Lab Vision. IL-1beta, IL-6, IL-8, IL-10, IL-12p70, and TNF-{alpha} were quantified using the BD cytometric bead array (BD Biosciences). The detection of OSM, CXCL5, MIP-3beta, CCL17, and vascular endothelial growth factor (VEGF) was conducted using ELISA kits bought from R&D Systems.

Flow cytometric and immunohistochemical analyses

For flow cytometric analyses, cells were incubated with the appropriate primary mAb (AN-G30, AN-N2, or AN-E1) or with an isotype control mAb followed by incubation with a PE-conjugated anti-mouse mAb and analyzed using a BD Biosciences flow cytometer. For immunohistochemical analysis, 10-µm cryostat sections were fixed, permeabilized, and immunostained with the relevant primary Ab (AN-R2) and the avidin peroxidase method (Vector Laboratories). Sections were counterstained with Mayer’s hematoxylin (Sigma-Aldrich) before mounting.

Gene expression profiling using cDNA arrays

Poly(A)+ RNA enrichment and hybridization to custom Atlas array membranes displaying 600 cDNAs (11) were performed according to the manufacturer’s recommendations (Clontech Laboratories) as previously described (12).

A study of the effects of 33 cytokines on the overall expression of 154 genes of potential interest for skin physiology was performed using keratinocyte designed cDNA microarrays (17).

Quantitative RT-PCR analysis

cDNA was synthesized from 2 µg of total RNA using random hexamer primers. Quantitative RT-PCR was conducted using the LightCycler FastStart DNA MasterPLUS SYBR Green I kit (Roche) and the following primers: gp130 (forward 5'-CCGCCACATAATTTATCAGT-3' and reverse 5'-AAGGTCTTGGACAGTGAATG-3'); OSMRbeta (forward 5'-AGATTGAACTCCATGGTGAA-3' and reverse 5'-GCTTCAAGTGTGGTGAAGTT-3'); LIFRbeta (forward 5'-TCTTGCGAGCCTATACAGAT-3' and reverse 5'-TCTGGATTTGGAATATCAGG-3'); S100A7, S100A8 and S100A9 (12), beta-defensin 2 (forward 5'-GCCATCAGCCATGAGGGTCTTG-3' and reverse 5'-AATCCGCATCAGCCACAGCAG-3'); filaggrin (forward 5'-AGGAACAGGCAAGGTCAAGTCCAG-3' and reverse 5'-CACGTGTGAACTCTTGGTGGCTCT-3'); OSM (forward 5'-TCAGTCTGGTCCTTGCACTC-3' and reverse 5'-CTGCAGTGCTCTCTCAGTTT-3'); and GAPDH (forward 5'-GAAGGTGAAGGTCGGAGTC-3' and reverse 5'-GAAGATGGTGATGGGATTTC-3') and hydroxymethylbilane synthase (12) as housekeeping genes.

Western blotting analysis

For STAT3 and MAPK phosphorylation and beta-tubulin expression, NHEK were lysed in SDS sample buffer, submitted to SDS-PAGE, transferred onto an Immobilon membrane, and stained with the appropriate Ab. The reaction was visualized by chemiluminescence. To determine the expression of the gp130, OSMRbeta, and LIFRbeta chains, cells were lysed in Brij 96 lysis buffer as described previously (18). Samples were subsequently incubated overnight with the indicated mAbs (AN-G30, AN-V2, or AN-E1), and the complexes were isolated using protein A beads before being treated as described above. Analysis of S100A7, S100A8, and S100A9 protein expression was conducted as previously described (12) on NHEK cultured in the absence or presence of OSM.


   Results
Top
 Abstract
 Introduction
 Materials and Methods
 Results
Discussion
 Disclosures
 References
 
Human keratinocytes express a functional type II OSMR on their surface

We first studied the expression profile of the type I and type II OSMR by NHEK by analyzing the expression levels of transcripts for the gp130, LIFRbeta, and OSMRbeta chains. NHEK, established from six different healthy donors, predominantly expressed transcripts for OSMRbeta and gp130, whereas only very faint levels of LIFRbeta mRNA were detected (Fig. 1A). In agreement with these results, NHEK were found to express both the gp130 and OSMRbeta chains, but no LIFR beta subunit, at their cell surfaces as shown by flow cytometric and Western blotting analyses (Fig. 1, B and C).


Figure 1
View larger version (38K):
[in this window]
[in a new window]

  		FIGURE 1. Type II OSM receptor expression and OSM-induced signaling pathways in NHEK. A, Quantitative RT-PCR analysis was conducted on total RNA from six independent NHEK cultures. gp130, OSMRbeta, and LIFRbeta mRNA expression levels are shown relative to the housekeeping GAPDH mRNA. B, Flow cytometric analysis of gp130, OSMRbeta, and LIFRbeta expression on NHEK. The dark gray histograms correspond to the isotype control Ab binding and the light gray histograms to the detection of gp130, OSMRbeta, or LIFRbeta, respectively. C, Western blot was performed on immunoprecipitated NHEK lysate using anti-gp130, anti-OSMRbeta, or anti-LIFRbeta Abs. The GO-G-UVM glioblastoma cell line was used as a positive control. D, NHEK were stimulated for 15 min in the presence or absence of the indicated concentrations of OSM. Phospho-STAT3 (P-STAT3) and STAT3 protein levels were determined by Western blotting. E, Cells were incubated for 2 h in the presence of 15 µg/ml neutralizing anti-gp130 and anti-OSMRbeta mAbs or an isotype control Ab before a 15-min stimulation with 50 ng/ml OSM. P-STAT3 and STAT3 were immunodetected as in D. F, NHEK were stimulated for 15 min with or without 50 ng/ml OSM or LIF. P-STAT3 and STAT3 were immunodetected as in D. G, Phospho-ERK (P-ERK) and ERK protein levels were analyzed by Western blotting in response to a 50 ng/ml OSM stimulation.

 
Engagement of a functional OSMR results in activation of STAT3, and therefore we analyzed the capacity of OSM to induce the activation of this signaling pathway in NHEK. As shown in Fig. 1D, stimulation of NHEK with OSM strongly induced tyrosine phosphorylation of STAT3. The addition of either a neutralizing anti-gp130 or an anti-OSMRbeta mAb to the cultures before OSM stimulation resulted in decreased STAT3 phosphorylation (Fig. 1E), indicating that both of the subunits defining the type II OSMR are involved in OSM-mediated STAT3 activation in keratinocytes. In contrast, stimulation of NHEK with LIF, at concentrations ranging from 3 to 100 ng/ml, did not result in STAT3 activation (Fig. 1F and data not shown).

Because signaling via the type II OSMR complex is also known to recruit the MAPK pathway (19), we measured ERK1/2 tyrosine phosphorylation levels in NHEK. Stimulation of NHEK with OSM led to a rapid increase in ERK1/2 phosphorylation levels (Fig. 1G). Taken together, these results demonstrate that human keratinocytes express a functional type II OSMR complex, but no type I OSMR complex, on their cell surface.

OSM modulates the expression of genes associated with human keratinocyte function

We next analyzed the keratinocyte gene expression profile and its regulation by OSM using macroarrays composed of cDNAs that were specifically designed to study keratinocyte structure and function (11). The results depicted in Fig. 2 are based on the analysis of transcripts expressed by NHEK, as well as by RHE following a 24-h stimulation with OSM. In both models OSM up-regulated the expression of 34 and 22 genes, respectively, encoding proteins involved in structure/metabolism, inflammation/innate immunity, or tissue remodeling. A major induction of transcripts was observed for genes encoding antimicrobial proteins such as S100A7-psoriasin and beta-defensin 2, as well as S100A8-calgranulin A, S100A9-calgranulin B, S100 neutrophil protein, platelet-derived growth factor A, TGF-beta, and CK6 (Fig. 2), which are produced in inflammatory situations. OSM also induced the transcription of genes associated with chemotaxis such as CXCL5, IL-8, and MIP-2{alpha}, as well as matrix metalloproteinase 1 and tenascin, involved in tissue remodeling. In addition, OSM specifically down-regulated a large set of genes encoding proteins associated with adhesion, the extracellular matrix, and keratinocyte differentiation such as CK1, CK10, calmodulin-like skin protein, calmodulin-related protein NB1, filaggrin, involucrin, and loricrin.


Figure 2
View larger version (67K):
[in this window]
[in a new window]

  		FIGURE 2. Gene expression profiles obtained from OSM-stimulated NHEK and RHE NHEK or RHE were cultured in the presence or absence of 10 ng/ml OSM for 24 h. Total RNA was isolated and used to make 33P-labeled cDNA probes, which were hybridized to skin designed array membranes displaying 600 cDNAs. The OSM-induced modulation was expressed as the ratio of the signal intensities for cells treated with OSM over unstimulated cells.

 
The expression of selected genes involved in keratinocyte activation (S100A7, S100A8, S100A9, and beta-defensin 2) or differentiation (filaggrin) was further studied by quantitative RT-PCR and Western blotting analyses. The results corroborated those from the analysis conducted using macroarrays (Fig. 3, A–D).


Figure 3
View larger version (41K):
[in this window]
[in a new window]

  		FIGURE 3. Biological effects of OSM on keratinocytes. A, NHEK were cultured with the indicated OSM concentrations for 48 h and a quantitative RT-PCR analysis of S100A7 mRNA expression was performed. Results are expressed as the relative expression of stimulated cells over control cells. B, NHEK were cultured for the indicated time in the presence of 10 ng/ml OSM and a quantitative RT-PCR analysis of S100A7 mRNA expression was performed. C, NHEK were cultured with or without 10 ng/ml OSM for 48 h and a quantitative RT-PCR analysis of S100A8, S100A9, beta-defensin 2, and filaggrin mRNA expression was performed. D, NHEK were cultured with or without 10 ng/ml OSM for 48 and 96 h. S100A7, S100A8, and S100A9 protein levels were determined by Western blotting. E, IL-8, CXCL5, and VEGF concentrations were determined by ELISA or cytometric bead array analysis in RHE culture supernatants after a 48-h stimulation with or without 10 ng/ml OSM.

 
The induction of growth factors and cytokine production in response to OSM was further studied by immunodetection in culture supernatants from NHEK or RHE. OSM increased the production of IL-8 and CXCL5, both chemokines with strong neutrophil chemoattractant activity (Fig. 3E), whereas the production of chemokines with different cell tropism (MIP-3beta and CCL17) was not affected (data not shown). The production levels of several major proinflammatory cytokines (IL-1beta, IL-6, IL-12p70, and TNF-{alpha}) was not modified by the addition of OSM (data not shown), suggesting that OSM stimulation may lead to a restricted inflammatory response in the epidermis. Finally, the production of VEGF, a major mediator of angiogenesis, was also induced in response to OSM (Fig. 3E), suggesting that OSM may contribute to the neovascularization of tissues in the inflammatory skin disease process. Taken together, these results indicate that, in keratinocytes, OSM is able to activate the transcription of a number of genes involved in innate immune responses, inflammation, tissue remodeling, and angiogenesis.

OSM is a potent inducer of keratinocyte migration and triggers hyperplasia of the reconstituted human epidermis

Keratinocytes play an important role in both the pathogenesis of cutaneous inflammatory diseases and the wound-healing process. We therefore analyzed the functional effects of OSM on human keratinocytes by using an in vitro wound-healing model, based on the induction of keratinocyte migration, in which proliferation is inhibited. As shown in Fig. 4, OSM strongly enhanced the motility of NHEK to a similar extent as that induced by epidermal growth factor, which is known to promote the migration of keratinocytes and was used as a positive control (13).


Figure 4
View larger version (34K):
[in this window]
[in a new window]

  		FIGURE 4. OSM induces keratinocyte migration in vitro. In vitro wounds were conducted in mitomycin-treated confluent NHEK culture and the keratinocytes were further cultured for 48 h with or without 10 ng/ml epidermal growth factor or OSM. A, Cell migration to the cell-free area was assessed as described in Materials and Methods. B, Each bar represents the mean ± SEM of migrating keratinocytes counted in four nonoverlapping fields. *, p < 0.001 compared with respective control without cytokine; based on an unpaired Student t test.

 
To extend these observations to a more dynamic model of epidermal differentiation, we investigated the effects of OSM on basal cell layer proliferation and keratinocyte differentiation using a reconstituted human epidermis. RHE grown in the absence of OSM presented a keratinized, multistratified epithelium containing intact basal, spinous, granulous, and cornified cell layers and numerous keratohyalin granules in the upper granular layer (Fig. 5). The addition of OSM to RHE triggered hyperplasia of the spinous keratinocyte layer, leading to an increase in the overall thickness of the reconstituted tissue. This effect was accompanied by a decrease of keratohyalin granules in the granular layer as well as by the presence of pyknotic nuclei. OSM-treated RHE were further characterized by an enhanced expression of S100A7, as well as a down-modulation of filaggrin and CK10 expression (Fig. 5), in agreement with the gene expression profile induced by OSM (Fig. 2).


Figure 5
View larger version (101K):
[in this window]
[in a new window]

  		FIGURE 5. OSM induces the hyperplasia of keratinocytes layers in RHE in vitro. Histological and immunohistochemical analysis of RHE either unstimulated or stimulated with 10 ng/ml OSM for 4 days. RHE were fixed and embedded in paraffin and 4-µm vertical sections were stained with H & E or with anti-CK10, anti-filaggrin, or anti-S100A7 mAbs.

 
Both type II OSMR expression and OSM production are enhanced in inflammatory skin diseases

Because OSM was found to be a potent inducer of keratinocyte motility and to trigger hyperplasia of RHE, suggesting its potential role in the pathogenesis of inflammatory skin disorders, we determined the expression of the OSMR beta-chain in psoriatic and atopic dermatitic lesions by immunohistochemical analysis. Lesions of both pathologies were characterized by a thickened epidermis, a decreased stratum granulosum, parakeratosis, and a strong up-regulation of S100A7 expression. In addition to the ubiquitous expression of gp130 (data not shown), the OSMR beta-chain was highly expressed in lesions from both psoriatic and atopic dermatitic skin, as compared with healthy tissue (Fig. 6A).


Figure 6
View larger version (47K):
[in this window]
[in a new window]

  		FIGURE 6. Expression of OSM and type II OSMR in skin inflammatory diseases. A, Ten-micrometer cryostat sections of skin biopsy from healthy donors and psoriatic or atopic dermatitic (AD) patients were fixed and subjected to immunohistochemistry for OSMRbeta and S100A7. One experiment representative of four is shown. B, OSM transcripts were PCR quantified from total RNA extracted from healthy skin and psoriatic or atopic dermatitic lesional skin (AD skin). C, Lesion-infiltrating T cells or peripheral blood-circulating T cells were expanded in vitro by one stimulation using anti-CD3 and anti-CD28 mAbs and IL-2. After a 12-day culture period, cells were stimulated again for 24 h before harvesting the culture supernatants for OSM determination. The p values were calculated using the unpaired Student t test. AD, atopic dermatitis.

 
Moreover, both psoriatic and atopic dermatitic lesions contained elevated levels of OSM mRNA, in contrast to biopsies taken from healthy skin where the expression of these transcripts was undetectable (Fig. 6B). To determine whether T cells infiltrating cutaneous inflammatory sites are a source of OSM, T cells were isolated from skin biopsies, expanded for 10–12 days in culture, and subsequently analyzed for their capacity to produce OSM. T cells isolated from the cutaneous lesions of patients with psoriasis or atopic dermatitis or derived from the peripheral blood of psoriatic patients produced higher levels of OSM following activation than peripheral blood-derived T cells from healthy individuals (Fig. 6C). Taken together, our results demonstrate that T cells infiltrating inflammatory skin lesions are important sources of OSM and therefore may contribute, via the induction of keratinocyte inflammation, to skin pathology.

OSM is one of the major cytokines involved in keratinocyte activation and differentiation

Skin inflammation results from the action of a cytokine network in which OSM is only a single player among many. To more precisely define the contribution of OSM to this process, its capacity to modulate the expression of keratinocyte inflammatory, innate immunity, and differentiation gene profile was compared with that of a comprehensive series of 33 cytokines, using microarray analysis.

The results from this extensive analysis showed that only few cytokines, i.e., IL-1{alpha} and beta, IL-6, IL-17, IL-20, IL-22, IL-24, and TNF-{alpha}, were able to induce a gene expression profile in NHEK comparable to that induced by OSM (data not shown). This finding was further sustained by quantitative RT-PCR analysis of S100A7 gene expression, showing that induction of this gene was restricted to the above-mentioned cytokines (Fig. 7A).


Figure 7
View larger version (30K):
[in this window]
[in a new window]

  		FIGURE 7. TNF-{alpha}, IL-17 and OSM are major modulators of S100A7 and beta-defensin 2 mRNA expression. A, NHEK were cultured in the presence or absence of the indicated cytokines (10 ng/ml) for 24 h. Relative S100A7 mRNA expression was determined by quantitative RT-PCR analysis. CNTF, Ciliary neurotrophic factor; CT, cardiotrophin 1; CLC, cardiotrophin-like cytokine; NP, neuropoietin; and TSLP, thymic stromal lymphopoietin. B, NHEK were stimulated for 24 h in the presence or absence of the indicated combination of TNF-{alpha}, IL-17, IL-22, IL-1{alpha}, or OSM (1 ng/ml). Relative S100A7 and beta-defensin 2 mRNA expression was determined by quantitative RT-PCR analysis. Results are expressed as the relative expression of stimulated cells as compared with control cells. C, RHE were stimulated for 24 h in the presence or absence of 10 ng/ml TNF-{alpha}, IL-17, and/or OSM. Relative S100A7 and beta-defensin 2 mRNA expression was determined by quantitative RT-PCR analysis. Results are expressed as the relative expression of stimulated cells as compared with control cells.

 
We next analyzed in detail the contribution of the most potent cytokine from each cytokine subfamily to the induction of S100A7 and beta-defensin 2 gene expression by quantitative RT-PCR. The combined effects of IL-1{alpha}, IL-17, IL-22, TNF-{alpha}, and OSM at a suboptimal concentration of 1 ng/ml led to a strong synergistic induction of the expression of analyzed genes (Fig. 7B). Furthermore, by successive elimination, IL-17, TNF-{alpha}, and OSM were identified as the major response-inducing cytokines (Fig. 7B). Finally, by using in vitro RHE we confirmed that, similarly, the combination of IL-17, TNF-{alpha}, and OSM led to a strong synergistic induction of S100A7 and beta-defensin 2 mRNA expression when compared with the action of each cytokine alone (Fig. 7C).


   Discussion
Top
 Abstract
 Introduction
 Materials and Methods
 Results
 Discussion
Disclosures
 References
 
Psoriasis and atopic dermatitis are the most frequent cutaneous inflammatory disorders affecting the population in Western countries. Although they differ in their origin, it is generally accepted that the pathogenesis of each of these diseases is associated with immune responses implicating the activity of T cells that reside in cutaneous inflammatory sites (20). In particular, the production by these cells of various set of cytokines is involved in the activation, proliferation, and hyperplasia of keratinocytes that are characteristics of the chronic cutaneous inflammation observed in these disorders.

In the present study, we show that OSM secreted by skin-infiltrating T cells is capable of modulating the expression of a large number of genes involved in keratinocyte function. These OSM-induced effects are mediated specifically via the type II OSMR, composed of the gp130 and OSMRbeta chains, which is, in contrast to the type I OSMR, functionally expressed on keratinocytes from healthy skin, thereby extending a recent report in the literature (21). Moreover, the expression of the OSMR-chain transcripts is strongly enhanced both in cutaneous lesions from patients with psoriasis or atopic dermatitis as compared with that in normal skin, suggesting an up-regulation of type II OSMR expression under conditions of cutaneous inflammation.

As shown in the present and previous studies, the interaction of the type II OSMR with its ligand results in the activation of STAT3 (22). The critical role of the STAT3 signaling pathway in the regulation of pathologic skin immune responses and, in particular, the pathogenesis of psoriasis has been well documented. Keratinocyte-specific ablation of STAT3 in a conditional transgenic mouse model was shown to lead to impaired skin remodeling because of a decrease in the growth factor-induced migration of keratinocytes (13). Moreover, transgenic mice expressing a constitutively active form of STAT3 in keratinocytes develop skin lesions resembling those of human psoriasis (23). It is of note that the induction of this particular phenotype in these transgenic mice not only requires activated STAT3 in keratinocytes but also their interaction with activated T cells, underscoring the importance of T cell-mediated immunity. Our observation that OSM-mediated signaling in human keratinocytes involves the activation of the STAT3 pathway and that the expression of both type II OSMR and OSM are increased in psoriatic lesions suggest that this cytokine might play a role in certain aspects of the pathogenesis of this disease in humans. During the reviewing process of the present work, a related study describing the importance of OSM in the induction of psoriasis-associated genes was published (24). Both studies underline a putative role for OSM in psoriasis. In contrast, the enhanced expression of type II OSMR and OSM in the lesional skin of patients with atopic dermatitis and the production of OSM by T cells isolated from these lesions indicate that OSM is likely to have a broader function in skin inflammation.

Indeed, among the predominant gene products induced by OSM in the cultures of primary keratinocytes and in the reconstituted epidermis are S100A7, also known as psoriasin, and S100A8 and S100A9, which belong to a family of small calcium-binding proteins with inflammation-inducing properties (25). The relevance of the induction of members of the S100 family of proteins by OSM in cutaneous inflammation is furthermore corroborated by the observation that S100A7, S100A8, and S100A9 are detected only at very low levels in the epidermis of healthy donors, whereas their expression is strongly induced in keratinocytes from psoriatic and atopic dermatitic lesions (26, 27).

Both S100A8 and S100A9 have chemotaxis-inducing activity and are strong chemoattractants for neutrophils (28). Moreover, OSM induces the production of IL-8 and CXCL5 by keratinocytes, known to mediate the chemoattraction of the latter cells via CXCR2 (29, 30, 31). Because cellular infiltrates in psoriatic contain large numbers of neutrophils (32) that are present in the so-called Munro’s microabscess, these results indicate that OSM, via its effect on keratinocytes, might be involved in leukocyte chemotaxis to these inflammatory skin lesions, thereby contributing to the local cutaneous inflammation.

Keratinocytes from psoriatic patients also produce high levels of antimicrobial peptides (3, 33). These peptides, present only at negligible levels in normal skin, are essential in the cutaneous innate immune response to invading microorganisms, as shown in animal models of infection (34). They might be, at least partially and independently of the bacteriocidal activity of neutrophils, responsible for the lesser susceptibility of psoriatic patients to infections with microorganisms, as compared to patients with atopic dermatitis who frequently suffer from serious skin infections. In particular, S100A7 has been shown to confer resistance to infection of the skin by Escherichia coli (35). Similarly, beta-defensin 2, another protein with anti-microbial activities (36) induced by OSM in human keratinocytes, is expressed at high levels in psoriatic lesions (37). The lower antimicrobial peptide production observed in atopic dermatitic skin, despite the increased expression of the type II OSMR and its ligand, could be a result of the concomitant increased production of IL-4, IL-10 and IL-13 in these patients, which have previously been described as inhibitors of beta-defensin 2 synthesis (3, 38).

As reported previously, transcripts for several STAT3-signaling cytokines, including IFN-{gamma}, IL-6, and the IL-10 related-cytokines IL-19, IL-20, and IL-22, are increased in psoriatic lesions (17, 39, 40). In addition, a number of cytokines that do not activate STAT3 following interaction with their respective receptors, such as IL-1, IL-17, and TNF-{alpha}, are also overexpressed in psoriasis (39, 41, 42), suggesting their implication in this disease. By comparing the capacity of a large series of cytokines to modulate the expression of genes associated with keratinocyte-mediated inflammation, chemotaxis, and innate immune responses, we found that among the STAT3-signaling cytokines OSM is one of the most potent mediators of keratinocyte activation. Moreover, by using combinations of IL-1{alpha}, IL-17, IL-22, TNF-{alpha}, and OSM, as well as successive subtractions of the latter cytokines, we were able to determine that IL-17, TNF-{alpha}, and OSM are important mediators in the induction of a subset of keratinocyte gene products associated with skin inflammation. The combination of these three cytokines leads to a very strong synergy with maximal values of gene induction of 104- to 105-fold at higher concentrations of cytokines.

Taken together, the results of our study demonstrate that OSM is one of the very few T cell-derived cytokines that is able to directly trigger keratinocyte activation via the recruitment of the STAT3 pathway. Because T cell infiltrates are a major source of OSM, this cytokine, together with an increased expression of its receptor components in both psoriatic and atopic dermatitic skin, may participate to the phenotype and tissue remodeling observed in these inflammatory skin diseases. Finally, our data show that OSM and its receptor play an important role in cutaneous inflammatory responses in general, whereas its specific effects associated with distinct inflammatory diseases depend on the cytokine environment.


   Disclosures
Top
 Abstract
 Introduction
 Materials and Methods
 Results
 Discussion
 Disclosures
References
 
The authors have no financial conflict of interest.


   Footnotes
 
The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

1 This study was supported by Grant 5176 from the Association pour la Recherche contre le Cancer, by the Post-genome Program of the Région Pays de la Loire and by the Programme Hospitalier de Recherche Clinique and R&D program of the CHU de Poitiers. C.D., E.V., and K.B. were supported by Grants from the Angers Agglomeration, the Société Française d’Hématologie, Ministère de la Recherche, and the Région Poitou-Charentes, respectively. Back

2 K.B. and C.D. contributed equally to this work. Back

3 Address correspondence and reprint requests to Dr. Jean-Claude Lecron, University de Poitiers, LabCytokines, Pole Biologie Sante, 40 Avenue du Recteur Pineau, Poitiers, France. E-mail address: jean-claude.lecron{at}univ-poitiers.fr or Dr. Hugues Gascan, Institut National de la Santé et de la Recherche Médicale, Unité Mixte 564, 4 Rue Larrey, F-49933 Angers, France. E-mail address: gascan{at}univ-angers.fr Back

4 Abbreviations used in this paper: OSM, oncostatin M; OSMR, OSM receptor; LIF, leukemia inhibitory factor; LIFR, LIF receptor; NHEK, normal human epidermal keratinocyte; RHE, reconstituted human epidermis; CK, cytokeratin; VEGF, vascular endothelial growth factor. Back

Received for publication April 3, 2006. Accepted for publication January 16, 2007.


   References
Top
 Abstract
 Introduction
 Materials and Methods
 Results
 Discussion
 Disclosures
 References
 

  1. Liang, S. C., X. Y. Tan, D. P. Luxenberg, R. Karim, K. Dunussi-Joannopoulos, M. Collins, L. A. Fouser. 2006. Interleukin (IL)-22 and IL-17 are coexpressed by Th17 cells and cooperatively enhance expression of antimicrobial peptides. J. Exp. Med. 203: 2271-2279. [Abstract/Free Full Text]
  2. Christophers, E., T. Henseler. 1987. Contrasting disease patterns in psoriasis and atopic dermatitis. Arch. Dermatol. Res. 279: S48-S51. [Medline]
  3. Nomura, I., E. Goleva, M. D. Howell, Q. A. Hamid, P. Y. Ong, C. F. Hall, M. A. Darst, B. Gao, M. Boguniewicz, J. B. Travers, D. Y. Leung. 2003. Cytokine milieu of atopic dermatitis, as compared to psoriasis, skin prevents induction of innate immune response genes. J. Immunol. 171: 3262-3269. [Abstract/Free Full Text]
  4. Richards, C. D., T. J. Brown, M. Shoyab, H. Baumann, J. Gauldie. 1992. Recombinant oncostatin M stimulates the production of acute phase proteins in HepG2 cells and rat primary hepatocytes in vitro. J. Immunol. 148: 1731-1736. [Abstract]
  5. Kamiya, A., T. Kinoshita, Y. Ito, T. Matsui, Y. Morikawa, E. Senba, K. Nakashima, T. Taga, K. Yoshida, T. Kishimoto, A. Miyajima. 1999. Fetal liver development requires a paracrine action of oncostatin M through the gp130 signal transducer. EMBO J. 18: 2127-2136. [Medline]
  6. Gearing, D. P., C. J. Thut, T. VandeBos, S. D. Gimpel, P. B. Delaney, J. King, V. Price, D. Cosman, M. P. Beckmann. 1991. Leukemia inhibitory factor receptor is structurally related to the IL-6 signal transducer, gp130. EMBO J. 10: 2839-2848. [Medline]
  7. Gearing, D. P., M. R. Comeau, D. J. Friend, S. D. Gimpel, C. J. Thut, J. McGourty, K. K. Brasher, J. A. King, S. Gillis, B. Mosley. 1992. The IL-6 signal transducer, gp130: an oncostatin M receptor and affinity converter for the LIF receptor. Science 255: 1434-1437. [Abstract/Free Full Text]
  8. Mosley, B., C. De Imus, D. Friend, N. Boiani, B. Thoma, L. S. Park, D. Cosman. 1996. Dual oncostatin M (OSM) receptors: cloning and characterization of an alternative signaling subunit conferring OSM-specific receptor activation. J. Biol. Chem. 271: 32635-32643. [Abstract/Free Full Text]
  9. Ishihara, K., T. Hirano. 2002. Molecular basis of the cell specificity of cytokine action. Biochim. Biophys. Acta. 1592: 281-296. [Medline]
  10. Dillon, S. R., C. Sprecher, A. Hammond, J. Bilsborough, M. Rosenfeld-Franklin, S. R. Presnell, H. S. Haugen, M. Maurer, B. Harder, J. Johnston, et al 2004. Interleukin 31, a cytokine produced by activated T cells, induces dermatitis in mice. Nat. Immunol. 5: 752-760. [Medline]
  11. Bernard, F. X., N. Pedretti, M. Rosdy, A. Deguercy. 2002. Comparison of gene expression profiles in human keratinocyte mono-layer cultures, reconstituted epidermis and normal human skin; transcriptional effects of retinoid treatments in reconstituted human epidermis. Exp. Dermatol. 11: 59-74. [Medline]
  12. Boniface, K., F. X. Bernard, M. Garcia, A. L. Gurney, J. C. Lecron, F. Morel. 2005. IL-22 inhibits epidermal differentiation and induces proinflammatory gene expression and migration of human keratinocytes. J. Immunol. 174: 3695-3702. [Abstract/Free Full Text]
  13. Sano, S., S. Itami, K. Takeda, M. Tarutani, Y. Yamaguchi, H. Miura, K. Yoshikawa, S. Akira, J. Takeda. 1999. Keratinocyte-specific ablation of Stat3 exhibits impaired skin remodeling, but does not affect skin morphogenesis. EMBO J. 18: 4657-4668. [Medline]
  14. Rosdy, M., B. Bertino, V. Butet, S. Gibbs, M. Ponec, M. Darmon. 1997. Retinoic acid inhibits epidermal differentiation when applied topically on the stratum corneum of epidermis formed in vitro by human keratinocytes grown on defined medium. In Vitro Toxicol. 10: 39-47.
  15. Yssel, H., H. Spits. 2001. In vitro culture of subpopulations of human T lymphocytes. Current Protocols in Immunology 7-19. Green & Wiley, New York.
  16. Trickett, A., Y. L. Kwan. 2003. T cell stimulation and expansion using anti-CD3/CD28 beads. J. Immunol. Methods 275: 251-255. [Medline]
  17. Boniface, K., J. C. Lecron, F. X. Bernard, G. Dagregorio, G. Guillet, F. Nau, F. Morel. 2005. Keratinocytes as targets for interleukin-10-related cytokines: a putative role in the pathogenesis of psoriasis. Eur. Cytokine Network 16: 309-319. [Medline]
  18. Diveu, C., A. H. Lak-Hal, J. Froger, E. Ravon, L. Grimaud, F. Barbier, J. Hermann, H. Gascan, S. Chevalier. 2004. Predominant expression of the long isoform of GP130-like (GPL) receptor is required for interleukin-31 signaling. Eur. Cytokine Network 15: 291-302. [Medline]
  19. Thoma, B., T. A. Bird, D. J. Friend, D. P. Gearing, S. K. Dower. 1994. Oncostatin M and leukemia inhibitory factor trigger overlapping and different signals through partially shared receptor complexes. J. Biol. Chem. 269: 6215-6222. [Abstract/Free Full Text]
  20. Lew, W., A. M. Bowcock, J. G. Krueger. 2004. Psoriasis vulgaris: cutaneous lymphoid tissue supports T-cell activation and ‘Type 1’ inflammatory gene expression. Trends Immunol. 25: 295-305. [Medline]
  21. Finelt, N., A. Gazel, S. Gorelick, M. Blumenberg. 2005. Transcriptional responses of human epidermal keratinocytes to oncostatin-M. Cytokine 31: 305-313. [Medline]
  22. Auguste, P., C. Guillet, M. Fourcin, C. Olivier, J. Veziers, A. Pouplard-Barthelaix, H. Gascan. 1997. Signaling of type II oncostatin M receptor. J. Biol. Chem. 272: 15760-15764. [Abstract/Free Full Text]
  23. Sano, S., K. S. Chan, S. Carbajal, J. Clifford, M. Peavey, K. Kiguchi, S. Itami, B. J. Nickoloff, J. DiGiovanni. 2005. Stat3 links activated keratinocytes and immunocytes required for development of psoriasis in a novel transgenic mouse model. Nat. Med. 11: 43-49. [Medline]
  24. Gazel, A., M. Rosdy, B. Bertino, C. Tornier, F. Sahuc, M. Blumenberg. 2006. A characteristic subset of psoriasis-associated genes is induced by oncostatin-M in reconstituted epidermis. J. Invest. Dermatol. 126: 2647-2657. [Medline]
  25. Roth, J., T. Vogl, C. Sorg, C. Sunderkotter. 2003. Phagocyte-specific S100 proteins: a novel group of proinflammatory molecules. Trends Immunol. 24: 155-158. [Medline]
  26. Broome, A. M., D. Ryan, R. L. Eckert. 2003. S100 protein subcellular localization during epidermal differentiation and psoriasis. J. Histochem. Cytochem. 51: 675-685. [Abstract/Free Full Text]
  27. Sugiura, H., H. Ebise, T. Tazawa, K. Tanaka, Y. Sugiura, M. Uehara, K. Kikuchi, T. Kimura. 2005. Large-scale DNA microarray analysis of atopic skin lesions shows overexpression of an epidermal differentiation gene cluster in the alternative pathway and lack of protective gene expression in the cornified envelope. Br. J. Dermatol. 152: 146-149. [Medline]
  28. Ryckman, C., K. Vandal, P. Rouleau, M. Talbot, P. A. Tessier. 2003. Proinflammatory activities of S100: proteins S100A8, S100A9, and S100A8/A9 induce neutrophil chemotaxis and adhesion. J. Immunol. 170: 3233-3242. [Abstract/Free Full Text]
  29. Yoshimura, T., K. Matsushima, S. Tanaka, E. A. Robinson, E. Appella, J. J. Oppenheim, E. J. Leonard. 1987. Purification of a human monocyte-derived neutrophil chemotactic factor that has peptide sequence similarity to other host defense cytokines. Proc. Natl. Acad. Sci. USA 84: 9233-9237. [Abstract/Free Full Text]
  30. Wuyts, A., P. Proost, J. P. Lenaerts, A. Ben-Baruch, J. Van Damme, J. M. Wang. 1998. Differential usage of the CXC chemokine receptors 1 and 2 by interleukin-8, granulocyte chemotactic protein-2 and epithelial-cell-derived neutrophil attractant-78. Eur. J. Biochem. 255: 67-73. [Medline]
  31. Koch, A. E., S. L. Kunkel, L. A. Harlow, D. D. Mazarakis, G. K. Haines, M. D. Burdick, R. M. Pope, A. Walz, R. M. Strieter. 1994. Epithelial neutrophil activating peptide-78: a novel chemotactic cytokine for neutrophils in arthritis. J. Clin. Invest. 94: 1012-1018. [Medline]
  32. Nickoloff, B. J.. 2001. Creation of psoriatic plaques: the ultimate tumor suppressor pathway: a new model for an ancient T-cell-mediated skin disease. J. Cutan. Pathol. 28: 57-64. [Medline]
  33. Gallo, R. L., M. Murakami, T. Ohtake, M. Zaiou. 2002. Biology and clinical relevance of naturally occurring antimicrobial peptides. J. Allergy Clin. Immunol. 110: 823-831. [Medline]
  34. Nizet, V., T. Ohtake, X. Lauth, J. Trowbridge, J. Rudisill, R. A. Dorschner, V. Pestonjamasp, J. Piraino, K. Huttner, R. L. Gallo. 2001. Innate antimicrobial peptide protects the skin from invasive bacterial infection. Nature 414: 454-457. [Medline]
  35. Glaser, R., J. Harder, H. Lange, J. Bartels, E. Christophers, J. M. Schroder. 2005. Antimicrobial psoriasin (S100A7) protects human skin from Escherichia coli infection. Nat. Immunol. 6: 57-64. [Medline]
  36. Harder, J., J. Bartels, E. Christophers, J. M. Schroder. 1997. A peptide antibiotic from human skin. Nature 387: 861-861. [Medline]
  37. Harder, J., J. M. Schroder. 2005. Psoriatic scales: a promising source for the isolation of human skin-derived antimicrobial proteins. J. Leukocyte Biol. 77: 476-486. [Abstract/Free Full Text]
  38. Howell, M. D., N. Novak, T. Bieber, S. Pastore, G. Girolomoni, M. Boguniewicz, J. Streib, C. Wong, R. L. Gallo, D. Y. Leung. 2005. Interleukin-10 downregulates anti-microbial peptide expression in atopic dermatitis. J. Invest. Dermatol. 125: 738-745. [Medline]
  39. Gearing, A. J., N. J. Fincham, C. R. Bird, M. Wadhwa, A. Meager, J. E. Cartwright, R. D. Camp. 1990. Cytokines in skin lesions of psoriasis. Cytokine 2: 68-75. [Medline]
  40. Grossman, R. M., J. Krueger, D. Yourish, A. Granelli-Piperno, D. P. Murphy, L. T. May, T. S. Kupper, P. B. Sehgal, A. B. Gottlieb. 1989. Interleukin 6 is expressed in high levels in psoriatic skin and stimulates proliferation of cultured human keratinocytes. Proc. Natl. Acad. Sci. USA 86: 6367-6371. [Abstract/Free Full Text]
  41. Murphy, J. E., C. Robert, T. S. Kupper. 2000. Interleukin-1 and cutaneous inflammation: a crucial link between innate and acquired immunity. J. Invest. Dermatol. 114: 602-608. [Medline]
  42. Teunissen, M. B., C. W. Koomen, R. de Waal Malefyt, E. A. Wierenga, J. D. Bos. 1998. Interleukin-17 and interferon-{gamma} synergize in the enhancement of proinflammatory cytokine production by human keratinocytes. J. Invest. Dermatol. 111: 645-649. [Medline]



This article has been cited by other articles:


Home page
 Am. J. Pathol.Home page
G. Tjabringa, M. Bergers, D. van Rens, R. de Boer, E. Lamme, and J. Schalkwijk
Development and Validation of Human Psoriatic Skin Equivalents
Am. J. Pathol., September 1, 2008; 173(3): 815 - 823.
[Abstract] [Full Text] [PDF]

Home page
 J. Immunol.Home page
R. Wolf, O. M. Z. Howard, H.-F. Dong, C. Voscopoulos, K. Boeshans, J. Winston, R. Divi, M. Gunsior, P. Goldsmith, B. Ahvazi, et al.
Chemotactic Activity of S100A7 (Psoriasin) Is Mediated by the Receptor for Advanced Glycation End Products and Potentiates Inflammation with Highly Homologous but Functionally Distinct S100A15
J. Immunol., July 15, 2008; 181(2): 1499 - 1506.
[Abstract] [Full Text] [PDF]

Home page
 Vet PatholHome page
D. M. Danilenko
Review Paper: Preclinical Models of Psoriasis
Vet. Pathol., July 1, 2008; 45(4): 563 - 575.
[Abstract] [Full Text] [PDF]

Home page
 FASEB J.Home page
A. Abtin, L. Eckhart, M. Mildner, F. Gruber, J.-M. Schroder, and E. Tschachler
Flagellin is the principal inducer of the antimicrobial peptide S100A7c (psoriasin) in human epidermal keratinocytes exposed to Escherichia coli
FASEB J, July 1, 2008; 22(7): 2168 - 2176.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Respir. Cell Mol. Bio.Home page
L. J. Quinton, M. R. Jones, B. E. Robson, B. T. Simms, J. A. Whitsett, and J. P. Mizgerd
Alveolar Epithelial STAT3, IL-6 Family Cytokines, and Host Defense during Escherichia coli Pneumonia
Am. J. Respir. Cell Mol. Biol., June 1, 2008; 38(6): 699 - 706.
[Abstract] [Full Text] [PDF]

Home page
 Sci SignalHome page
A. Linden
A Role for the Cytoplasmic Adaptor Protein Act1 in Mediating IL-17 Signaling
Sci. Signal., August 7, 2007; 2007(398): re4 - re4.
[Abstract] [Full Text] [PDF]

This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Boniface, K.
Right arrow Articles by Lecron, J.-C.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Boniface, K.
Right arrow Articles by Lecron, J.-C.

HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS