京都大学 / 新制・課程博士 / 博士(農学) / 甲第23579号 / 農博第2478号 / 新制||農||1088(附属図書館) / 学位論文||R3||N5363(農学部図書室) / 京都大学大学院農学研究科応用生命科学専攻 / (主査)教授 栗原 達夫, 教授 小川 順, 教授 木岡 紀幸 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DGAM

Atopiskt eksem kännetecknas av en torr hud med hudsprickor som ger en svår klåda. Behandlingen går ut på att identifiera, minimera och eliminera faktorer som är utlösande och försämrande. Mjukgörande medel används dagligen för att före-bygga uppkomsten av nytt eksem. Att leva med atopiskt eksem kan vara ett stort handikapp med personliga, sociala och ekonomiska inskränkningar som leder till en sämre livskvalitet. Syftet med litteraturstudien är att klargöra om patienter med atopiskt eksem kan förbättra sin livskvalitet genom att få utbildning om sin sjuk-dom. Metoden som har använts är en litteraturstudie där artiklar har sökts i data-basen PubMed och bedömts efter ett modifierat granskningsprotokoll för kvali-tetsvärdering av artiklarna. Sammanställningen bygger på 10 artiklar där resultatet inte ger ett starkt stöd för att patientutbildning ger en förbättrad livskvalitet. Ytter-liggare forskning behövs med större och mer omfattande studier för att kunna på-visa huruvida patientutbildning ger förbättringar i livskvaliteten hos patienter med atopiskt eksem. / Atopic eczema is characterized by a dry skin with dermal tearing giving a severe itching. The treatment is to identify, minimize and eliminate factors that trigger and adverse. Softening agents are used daily to prevent the formation of new eczema. Living with atopic eczema can be a major handicap with personal, social and economic restrictions that might lead to a reduced quality of life. The purpose of this literature study is to clarify whether patients with atopic eczema may improve their quality of life by receiving education of their illness. The method used is a literature review which items have been sought in the database PubMed and assessed by a modified examination protocol for quality assessment of articles. The compilation is based on 10 articles in which the results do not provide strong support for patient education provides an improved quality of life. Further research is needed with larger and more extensive studies to demonstrate if improvements can be shown in quality of life in patients with atopic eczema.

Chronic itch has a significant impact on quality of life for millions of patients worldwide, on a level comparable to that of chronic pain. Yet, although there are a host of effective drugs available for pain, there are no therapies that specifically target chronic itch. Current experimental approaches to investigate the pathogenesis of chronic pruritus and to test novel therapeutic agents are largely limited to rodent models. However, rodent models display significant dermatological, neurophysiological, and immunological differences from humans with chronic itch. The disadvantages of the current rodent paradigms call for the design of a valid primate model of chronic itch. For four years, we have monitored scratching behavior in a primate colony (n=35) of Cynomolgus macaques (Macaca fascicularis) suffering from idiopathic chronic itch. By comparing molecular and genetic analyses of the primates’ skin to their quantified scratching behavior, we attempted to characterize the underlying mechanisms of chronic itch in this model. Furthermore, the expression of itch-related proteins was examined in both the primate model and in humans with pruritic diseases. The first aim of the study was to characterize the underlying molecular and genetic basis of chronic itch in the primate model. We were able to distinguish specific peripheral targets related to pruritus by correlating the genetic and protein expression results to the primates’ scratching severity. In Aim 1a, RNA-sequencing was performed on skin biopsies from the primates to identify differentially expressed genes in pruritic, lichenified versus non-pruritic, non-lichenified skin. These results were then correlated to the quantified primate scratching behavior. This led to the identification of over 400 genes that were differentially expressed in the skin based on scratching intensity. Many of these differentially expressed transcripts were associated with sensory nerve fibers, keratinocytes, mast cells, or lymphocytes. Selected genes that were overexpressed and correlated to itch intensity were then targeted for immunohistochemical and proteomic analysis in Aim 1b. Immunohistochemical examination of the primate skin biopsies revealed that histamine levels were not elevated in primates that exhibited increased scratching behavior. However, mast cells containing tryptase were significantly increased in the skin of primates with severe scratching as compared to primates with mild scratching. The increased levels of gastrin-releasing peptide and substance P in lichenified skin were also found to be correlated to the primates’ scratching behavior. Of note, transient receptor potential channels V1, V3, and A1 were increased in the epidermis of primate skin, but the numbers of TRPV1+ and TRPA1+ nerve fibers were not significantly different between lichenified and non-lichenified skin. Transcriptome analysis of the opioid receptors and their ligands showed that primates with severe scratching behavior had a significant imbalance between the µ- and κ-opioid receptors and ligands. The µ-opioids had upregulated gene expression, while the κ-opioids were downregulated. In Aim 2, to further characterize this primate model of chronic itch, we compared immunohistochemical results from the primate studies to human findings. Lesional and non-lesional skin biopsies from patients with atopic dermatitis, psoriasis, and cutaneous T-cell lymphoma underwent immunohistochemical analysis in order to reveal the similarities and differences between the primate model and different types of chronic itch in humans. As in the primate model, substance P was found to be increased in the skin of lesional atopic and psoriasis skin. Additionally, similar to primate skin, human atopic and psoriatic skin had high levels of tryptase and its receptor in the epidermis. While IL-31 was only slightly elevated in primates, patients with cutaneous T-cell lymphoma or atopic dermatitis showed a significant correlation between itch severity and IL-31 levels. In conclusion, our primate model displayed expression patterns of many endogenous pruritogens and receptors that were similar to those of humans with atopic dermatitis or psoriasis. While the primate model did not completely mimic these specific pruritic diseases, the overlap of pruritic components suggests a commonality of signaling pathways across several different chronic itch states. The similarity of this primate model to human disease offers the combined advantages of experimental modeling and long-term behavioral follow-up. / Biomedical Sciences

Introduction: Atopic dermatitis (AD) is characterized by chronic pruritic relapsing eczematous lesions of the skin. Eosinophilic inflammation in AD is driven by activation of type 2 inflammatory cells including CD4+ T cells and type 2 innate lymphoid cells (ILC2s). We have shown that type 2 cytokines, namely interleukin (IL)-5 and IL-13, stimulate migration and terminal differentiation of eosinophil progenitor cells (EoPs). We propose that these cytokines are important drivers of tissue eosinophilia in AD lesional skin. This study aimed to quantify, by flow cytometry, cells that produce type 2 cytokines in lesional skin compared to peripheral blood from moderate-severe AD patients. Methods: In a cross-sectional study of patients with moderate-to-severe AD (n=16), type 2 inflammatory cells were enumerated in blood and cells extracted from excised skin biopsies. By flow cytometry, live, singlet CD45+cells were identified as ILC2 (lin-CD127+CD294+), EoP (CD34+125+), and CD4+ T cells (Lin+CD3+CD4+). Intracellular expression of type 2 cytokines (IL-5 and IL-13) were evaluated in each cell population. In addition, we developed a protocol to enumerate ILC2s by fluorescence immune-histochemistry in lesional versus non-lesional skin samples and skin biopsies taken 24h post-intradermal challenge with allergen versus diluent. Data are expressed as median (interquartile range [IQR]) unless otherwise stated. Cross compartmental comparisons were made using the Wilcoxon rank-sum test and where applicable, correlational analyses were performed using a Spearman’s rank-correlational test. Results: There was a significantly higher number of total ILC2s in lesional skin compared to blood from AD subjects (556 [99 – 5501] vs 235 [67 – 569] cells/mL, p=0.03). Similarly, IL-5+, IL-13+ ILC2s, were significantly greater in skin compared to blood (6 [1 – 666] vs 1 [1 – 19] cells/mL, p=0.03; 28 [1 – 1357] vs 1 [1 – 7] cells/mL, p=0.01, respectively). We found higher numbers of total and type 2 cytokine positive EoP in lesional skin biopsies from AD patients compared to blood (Total EoP: 815 [285 – 2794] vs 112 [46 – 247] cells/mL, p<0.01; IL-5+EoP: 36 [1 – 129] vs 1 [1 – 23] cells/mL, p=0.07; IL-13+EoP: 92 [10 – 182] vs 1 [1 – 8] cells/mL, p<0.01 and IL-5+IL-13+ILC2: 70 [1 – 158] vs 1 [1 – 12] cells/mL, p=0.02, respectively). In contrast, significantly higher numbers of total and type 2 cytokine positive CD4+ cells were found in blood compared to lesional skin biopsies from AD patients (Total CD4+: 1092 [650 – 1742] vs 58.3 [35.3– 152.4] x 103 cells/mL, p<0.01 and IL-5+IL-13+CD4+ cells: 13.5 x 103 [2.1 x 103 – 42.9 x 103] vs 3.8 x 103 [1.6 x 103 – 4.9 x 103] cells/mL, p=0.02, respectively). For IF staining, there was a significant higher number of ILC2s in lesional compared to non-lesional skin biopsies and biopsies taken 24h post allergen- compared to diluent challenge (1 [0 – 2] vs 0 [0 - 0] cells/mm2, p=0.008, and 2 [1 – 2] vs 0 [0 – 0] cells/mm2, p=0.0002, respectively). Interestingly, in sex analyses we found significantly greater levels of blood ILC2 in females compared to males, but this not was found in the skin. Importantly, we found a significant correlation between lesional skin levels of ILC2 measured by flow cytometry and clinical measures of disease severity/symptoms as reported/calculated from the Patient-Oriented Eczema Measure questionnaire (POEM) score (total ILC2: r=0.55, p=0.04; IL-13+ ILC2s, r=0.61, p=0.02 and IL-5+ IL-13+ ILC2s: r=0.75, p=0.002). Conclusions: Preferential increases in skin-resident ILC2 that produce a type 2 rich environment were found in AD subjects. These levels correlated with patient-oriented measure of disease severity. We propose that this increase may encourage recruitment of mature eosinophils and EoP and possibly drive localized differentiation of EoP into mature eosinophils that may drive the pathology of AD lesions. Furthermore, immunofluorescence staining may be a suitable alternative to flow cytometry for identification of ILC2 in the event of a low cell count. These techniques can be used in future studies that target ILC2 biology to fully understand the role of these cells in driving AD. / Thesis / Master of Science (MSc)

Atopic dermatitis (AD) is a common skin disease that is characterized by chronic, relapsing skin inflammation and eczematous, itchy lesions. In AD, systemic and local eosinophilia and basophilia is thought to contribute to disease progression in both acute and chronic lesions. It has been previously shown that in chronic allergic inflammatory diseases, tissue eosinophilia and basophilia may in part result from eosinophil/basophil (Eo/B) progenitors trafficking from the bone marrow and maturing in tissue in response to type 2 cytokines including IL-5 and IL-3. We therefore proposed that a similar mechanism could be contributing to the pathogenesis of AD. First, we compared lesional and non-lesional AD tissue, and found approximately 10-fold higher levels of Eo/B progenitors in the lesional tissue (p<0.05). As previous research has shown an increase in Eo/B progenitors in the airways of allergic asthmatics post inhaled allergen challenge, we next examined whether Eo/B progenitors increased locally in the acute phase of AD using the intradermal allergen challenge model. Compared to intradermal diluent challenge there was an increase in Eo/B progenitors (5.5-fold), eosinophils (18-fold) and basophils (2.5-fold) 24 hours post intradermal allergen challenge (all p<0.05). These increases were consistent with findings in allergic airways. Lastly, we examined the relationship between disease severity and Eo/B progenitors in inflamed lesional (chronic) and allergen-challenged (acute) tissue. We found that Eo/B progenitors in lesional tissue positively correlated with disease severity (EASI R=0.71, p<0.05 and SCORAD R=0.65, p<0.05), while in allergen-challenged tissue a trend was seen for a positive correlation between Eo/B progenitors and disease severity (EASI R=0.48, p=0.07 and SCORAD R=0.46, p=0.09). These results highlight the potential involvement of Eo/B progenitors in the disease pathogenesis of AD. / Thesis / Master of Science (MSc) / Atopic dermatitis is a common skin disease that is characterized by chronic, relapsing skin inflammation and eczematous, itchy lesions. In other allergic diseases, a cell called the “eosinophil/basophil progenitor” contributes to the accumulation of inflammatory cells in the diseased organ. We proposed that eosinophil/basophil progenitors found in the skin may be contributing to the development of local allergic inflammation. In patients with moderate-to-severe atopic dermatitis we compared acute responses to intradermal allergen and chronic skin lesions to diluent-challenged and un-affected skin, respectively. Allergen-challenged skin had more eosinophil/basophil progenitors, mature eosinophils and basophils 24 hours’ post-challenge compared to unchallenged skin (p<0.05). Chronic skin lesions had more eosinophil/basophil progenitors than un-affected skin (p<0.05). The number of eosinophil/basophil progenitors positively correlated to disease severity as determined by EASI and SCORAD. Our results suggest that accumulation of eosinophil/basophil progenitors in skin of atopic dermatitis patients could support allergic inflammation and contribute to disease severity.

[ES] Nuestra investigación se centra en comprender los mecanismos moleculares que median las acciones de los glucocorticoides (GCs) en la fisiopatología de la piel mediante el análisis funcional del receptor de GCs (GR) y el receptor de mineralocorticoides (MR), dos proteínas altamente relacionadas estructural y funcionalmente, que actúan como factores de transcripción dependientes de ligando. Nuestros datos previos demuestran que GR juega un papel central en el desarrollo de la piel; en la edad adulta, tanto GR como MR actúan como mediadores anti-inflamatorios en enfermedades cutáneas (Sevilla et al. 2013; Boix et al. 2016). No obstante, desconocíamos si los receptores ejercían funciones cooperativas o antagónicas en la epidermis. Esta tesis doctoral se ha centrado en la generación y caracterización de ratones con inactivación específica en la epidermis de GR y MR (ratones double knock-out o DKO). Al nacer, los DKO mostraron un fenotipo cutáneo con diferenciación epidérmica defectuosa y un estado inflamatorio único caracterizado por infiltrados inmunes epiteliales y alteraciones en la expresión génica, similar a las lesiones psoriáticas. Este fenotipo fue mucho más severo que el de los KO individuales (ratones GR epidermal KO o GREKO y MR epidermal KO o MREKO), pero se resolvió espontáneamente a partir del día post-natal 3. En la edad adulta, la piel DKO mostró un aumento en el grosor epidérmico, similar al de los KO individuales. Todos los ratones KO mostraron una mayor susceptibilidad a la inflamación aguda respecto a los controles (CO), que no se contrarrestó de forma efectiva por un tratamiento tópico con GCs. Además, los ratones DKO mostraron una mayor susceptibilidad a la psoriasis inducida por imiquimod respecto a los KO individuales. El aumento de la respuesta inflamatoria en los DKO era consistente con un aumento significativo de la actividad de AP-1 y NF-kappaB en queratinocitos DKO respecto a los CO o KO individuales. En conjunto, nuestros datos demuestran que GR y MR epidérmicos actúan de manera cooperativa para contrarrestar la inflamación de la piel, durante el desarrollo y la edad adulta, y que ambos son necesarios para una respuesta transcripcional óptima y una actividad terapéutica de los GCs. Los tratamientos prolongados con dosis farmacológicas de GCs producen defectos como la atrofia cutánea, similar a la que tiene lugar durante el envejecimiento cronológico, que correlaciona con un aumento de los niveles locales endógenos de GCs. Este trabajo ha abordado las consecuencias fenotípicas de la pérdida epidérmica de MR durante el envejecimiento cronológico y los mecanismos involucrados. Los ratones MREKO de 13 meses de edad fueron resistentes a la atrofia epidérmica pero mostraron un menor grosor dérmico y depósito de colágeno, en parte debido a una disminución de la actividad SMAD2/3 respecto a la piel de ratones CO. Además, el tejido adiposo subcutáneo (dWAT) se engrosó 2.5 veces en MREKO vs CO a los 13 meses, con hiperplasia e hipertrofia de adipocitos. Estos cambios se desencadenaron, al menos en parte, a través de alteraciones en la señalización mediada por GCs, y la activación de WNT/beta-catenina inducida por señales paracrinas epidérmicas que condujeron al aumento de expresión de Pparg. Estos resultados demuestran un papel crucial de MR epidérmico en la regulación del cross-talk entre compartimientos durante el envejecimiento cronológico de la piel. / [CA] La nostra investigació se centra en comprendre els mecanismes moleculars que regulen les accions dels glucocorticoides (GCs) en la fisiopatologia de la pell mitjançant l'anàlisi funcional del receptor de GCs (GR) i el receptor de mineralocorticoides (MR), dues proteïnes altament relacionades estructural i funcionalment, que actuen com a factors de transcripció dependents de lligant. Els nostres resultats previs demostren que GR juga un paper central en el desenvolupament de la pell; en l'edat adulta, tant GR com MR actuen com a mediadors antiinflamatoris en malalties cutànies (Sevilla et al. 2013; Boix et al. 2016). No obstant, desconeixíem si els receptors exercien funcions cooperatives o antagòniques en l'epidermis. Aquesta tesi doctoral s'ha centrat en la generació i caracterització de ratolins amb inactivació específica en l'epidermis de GR i MR (ratolins double knock-out o DKO). En néixer, els DKO van mostrar un fenotip cutani amb diferenciació epidèrmica defectuosa i un estat inflamatori únic caracteritzat per infiltrats immunes epitelials i alteracions en l'expressió gènica, similar a les lesions psoriàtiques. Aquest fenotip va ser molt més sever que el dels KO individuals (ratolins GR epidermal KO o GREKO i MR epidermal KO o MREKO), però es va resoldre espontàniament a partir del dia post-natal 3. En l'edat adulta, la pell DKO va mostrar un augment en el gruix epidèrmic, similar al dels KO individuals. Tots els ratolins KO van mostrar una major susceptibilitat a la inflamació aguda en comparació als controls (CO), que no va ser contrarestada de manera efectiva per un tractament tòpic amb GCs. A més, els ratolins DKO van mostrar una major susceptibilitat a la psoriasis induïda per imiquimod respecte als KO individuals. L'augment de la resposta inflamatòria en els DKO era consistent amb un augment significatiu de l'activitat d'AP-1 i NF-kappaB en queratinòcits DKO respecte als CO o KO individuals. En conjunt, les nostres dades demostren que GR i MR epidèrmics actuen de manera cooperativa per contrarestar la inflamació de la pell, durant el desenvolupament i l'edat adulta, i que tots dos són necessaris per a una resposta transcripcional òptima i una activitat terapèutica dels GCs. Els tractaments prolongats amb dosis farmacològiques de GCs produeixen defectes com l'atròfia cutània, similar a la que té lloc durant l'envelliment cronològic, que correlaciona amb un augment dels nivells locals endògens de GCs. Aquest treball ha abordat les conseqüències fenotípiques de la pèrdua epidèrmica de MR durant l'envelliment cronològic i els mecanismes involucrats. Els ratolins MREKO de 13 mesos d'edat van ser resistents a l'atròfia epidèrmica però van mostrar un menor gruix dèrmic i dipòsit de col¿lagen, en part a causa d'una disminució de l'activitat SMAD2/3 respecte a la pell de ratolins CO. A més, el teixit adipós subcutani (dWAT) es va engrossir 2.5 vegades en MREKO vs CO als 13 mesos, amb hiperplàsia i hipertròfia d'adipòcits. Aquests canvis es van desencadenar, almenys en part, a través d'alteracions en la senyalització mediada per GCs, i l'activació de WNT/beta-catenina induïda per senyals paracrines epidèrmiques que van conduir a l'augment d'expressió de Pparg. Aquests resultats demostren un paper crucial de MR epidèrmic en la regulació del cross-talk entre compartiments durant l'envelliment cronològic de la pell. / [EN] Our research focuses on understanding the molecular mechanisms that mediate the actions of glucocorticoids (GCs) in skin pathophysiology through functional analysis of the GC receptor (GR) and the mineralocorticoid receptor (MR), two highly related structural and functionally proteins, which act as ligand-dependent transcription factors. Our previous data show that GR plays a central role in skin development; in adulthood, both GR and MR act as anti-inflammatory mediators in skin diseases (Sevilla et al. 2013; Boix et al. 2016). However, we did not know if the receptors exerted cooperative or antagonistic functions in the epidermis. This doctoral thesis has focused on the generation and characterization of mice with specific inactivation in the epidermis of GR and MR (double knock-out or DKO mice). At birth, DKO show a skin phenotype with defective epidermal differentiation and a unique inflammatory state characterized by epithelial immune infiltrates and alterations in gene expression, similar to psoriatic lesions. This phenotype was much more severe than that of individual KO (GR epidermal KO or GREKO and MR epidermal KO or MREKO mice), but resolved spontaneously from postnatal day 3. In adulthood, DKO skin showed an increase in epidermal thickness, similar to that of individual KO. All KO mice showed greater susceptibility to acute inflammation compared to controls (CO), which was not effectively counteracted by topical treatment with GCs. Furthermore, DKO mice show a greater susceptibility to imiquimod-induced psoriasis relative to individual KO. The increased inflammatory response in DKO was consistent with a significant increase in AP-1 and NF-kappaB activity in DKO keratinocytes relative to CO or individual KO. Taken together, our data show that epidermal GR and MR act cooperatively to counteract skin inflammation, during development and adulthood, and that both are required for optimal transcriptional response and therapeutic activity of GCs. Prolonged treatments with pharmacological doses of GCs produce defects such as cutaneous atrophy, similar to that which occurs during chronological aging, which correlates with an increase in endogenous local levels of GCs. This work has addressed the phenotypic consequences of epidermal loss of MR during chronological aging and the mechanisms involved. The 13-month-old MREKO mice were resistant to epidermal atrophy but displayed reduced dermal thickness and collagen deposition, in part due to a decrease in SMAD2 3 activity relative to the skin of CO mice. In addition, the subcutaneous adipose tissue (dWAT) thickened 2.5 times in MREKO vs CO at 13 months, with hyperplasia and hypertrophy of adipocytes. These changes were triggered, at least in part, through alterations in GC-mediated signaling, and the activation of WNT/beta-catenin induced by epidermal paracrine signals that led to increased expression of Pparg. These results show a crucial role for epidermal MR in the regulation of the cross-talk between compartments during chronological skin aging. / Este trabajo ha sido realizado con el apoyo económico de los proyectos de investigación que se enumeran a continuación: SAF2014-59474-R, SAF2017-88046-R. Judit Bigas Corominas ha disfrutado de una beca predoctoral FPI (BES2015-072722) otorgada por el Ministerio de Economía y Competitividad, asociada al proyecto SAF2014-59474-R. Agradecemos el apoyo de COST ADMIRE BM-1301 y NuRCaMeIn (SAF2015-71878-REDT y SAF2017-90604-REDT). / Bigas Corominas, J. (2020). Contribuciones relativas de los receptores de glucocorticoides y mineralocorticoides en la biología cutánea [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/156214

No / This review focuses on treatment targets for the most common inflammatory skin diseases, eczema and psoriasis with an emphasis on cytokines expressed in the uppermost layer of the skin which is easily accessible for diagnostic and therapeutic approaches. Recently, a significant body of research has highlighted the influence of the skin barrier and the patients’ microbiome on skin inflammatory responses and we will comment on their impact on mediator regulation. Itch is a prominent dermatology symptom which is influenced by cytokines and can via itch–scratch cycle impact on the skin barrier and mediator expression associated with damage. Taking the contribution of pruritus and superficial skin damage into account, we address cytokines as targets for stratified treatment approaches in subgroups of eczema and psoriasis.

No / Interleukin-33 has recently gained much attention due to its role in allergic responses. It has been shown to amplify Th2 responses and to act as a damage-associated molecular pattern. IL-33 acts on a broad range of cells and has been proposed to link innate and adaptive features of allergic responses. It was the aim of this study to investigate this property of IL-33 in the inflammatory response characterising atopic dermatitis (AD). We have analysed the response of skin-resident cells derived from patients with AD and healthy donors with regard to the expression of IL-33 and its receptor ST2. The functional impact of IL-33 on CD4+ T cells was investigated. Keratinocytes and dermal fibroblasts clearly differ in their regulation of IL-33. In fibroblasts, the concerted action of TNF-α and IL-1β was the strongest inducer, whereas IFN-γ is clearly the key molecule that upregulates IL-33 in keratinocytes with a more pronounced response of cells derived from patients with AD. Keratinocytes from patients with AD showed a markedly higher constitutive expression level of surface ST2. CD4+ T cells respond to IL-33. Unexpectedly, IL-33 failed to induce a significant secretion of IL-5 or IL-13. By contrast, high amounts of IFN-γ were detectable if IL-33 was added to the T-cell receptor-stimulated cells or in combination with IL-12. These results suggest that IL-33 and IFN-γ are closely interlinked in epidermal AD inflammation. IFN-γ induces IL-33 in keratinocytes and IL-33 acts on activated T cells to further increase the release of IFN-γ, therefore contributing to drive skin inflammation towards chronic responses.

No / Background  Interleukin (IL)-33 is a member of the IL-1 family and has been implicated in Th2-driven allergic diseases such as atopic dermatitis (AD) and asthma. The principal Th2 cytokine IL-4, found highly expressed in acute allergic eczema, is known to downregulate human β-defensin 2 (hBD2) expression in human keratinocytes and this is associated with superinfection in patients with AD. Objectives  To investigate the effect of IL-33 on the expression of hBD2 in human keratinocytes. Methods  hBD2 production by stimulated keratinocytes was measured by enzyme-linked immunosorbent assay. Results  Our results showed that serum is a very potent inducer of hBD2 and 2·5% human serum was much more potent in inducing hBD2 than 20 ng mL−1 of tumour necrosis factor-α. Interestingly, serum from patients with AD showed an impaired ability to induce hBD2 in normal keratinocytes. IL-33 significantly downregulated serum-induced hBD2. The downregulatory capacity of IL-33 was found to be 1·5- to 2-fold weaker compared with IL-4. Conclusions  Our data suggest that IL-33 can significantly contribute to the decreased expression of hBD2 in acute eczematous reaction clinically characterized by spongiosis and oozing – thus indicative for contact of the epidermis with serum components.

京都大学 / 新制・論文博士 / 博士(社会健康医学) / 乙第13613号 / 論社医博第19号 / 京都大学大学院医学研究科社会健康医学系専攻 / (主査)教授 森田 智視, 教授 椛島 健治, 教授 村井 俊哉 / 学位規則第4条第2項該当 / Doctor of Public Health / Kyoto University / DFAM