AB196 Abstracts
J ALLERGY CLIN IMMUNOL FEBRUARY 2012
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Effects of Nasal Allergen Challenge on T cell signature in Peripheral Blood in Patients with Severe Seasonal Allergic Rhinitis M. H. Shamji, V. Bellido, G. Scadding, J. A. Leyhadi, M. Calderon, A. Togias, N. Tchao, M. Plaut, L. Turka, D. Phippard, S. Durham; Imperial College London, South Kensington, UNITED KINGDOM. RATIONALE: Seasonal allergic rhinitis (SAR) is characterised by Th2-T cell driven IgE-dependent inflammation in the nasal mucosa. The aim of this study was to evaluate the time-course of the effect of grass pollen nasal allergen challenge on T cell signature in peripheral blood in patients with SAR. METHODS: Twelve patients with SAR were recruited outside the grass pollen season. All patients underwent diluent/saline challenge followed by nasal allergen challenge 14 days later. Total nasal symptoms, visual analogue, subjective nasal blockage, peak nasal inspiratory flow and grass pollen-driven basophil activation and T cell responses in the peripheral blood were assessed before and 3, 6 and 24hr after challenge. RESULTS: During the early and late allergic response, an increase in TNSS (AUC, p 50.002; p50.022), VAS (p50.003, p50.003) and decrease in PNIF (p50.03; p50.03) was observed. Basophil reactivity was increased after nasal allergen challenge at 3hr for CRTH2+CD107a+ (p50.02), 6hr for CRTH2+CD63+ (p50.003) and a trend increase at 24hr for CRTH2+CD203c+ (p50.06) basophils. CD4+CD25lo T effector cells were increased after nasal allergen challenge but not diluent and a parallel increase in CD80 (p50.08), CD86 (p50.02) expression on pDCs. Interestingly, antigen-driven CD4+ T cell proliferative responses and frequency of IL-4+ CD4+ T cells were significantly increased at 6hr after nasal allergen challenge when compared to baseline (p50.01 and p50.02). No change in IFN-g+CD4+T cells was observed. CONCLUSIONS: Nasal allergen challenge is associated with increases in basophil reactivity, CD4+ T cell proliferation and frequency of grass pollen-specific IL-4+CD4+ T cells at 6hr in peripheral blood.
IL-4 Controls The Phenotypic Conversion Of Effector Memory CD8+ T Cells To IL-13-Producing Cells That Enhance AllergenInduced Airway Hyperresponsiveness And Inflammation Y. Jia, K. Takeda, J. Han, A. Joetham, J. J. Lucas, E. W. Gelfand; National Jewish Health, Denver, CO. RATIONALE: IL-13-producing effector memory CD8+ T cells play a pivotal role in the development of airway hyperresponsiveness (AHR) and inflammation in severe asthmatics and experimental models. The mechanism underlying the phenotypic conversion of CD8+ Teff cells from IFN-gamma-producing to IL-13-producing cells has not been defined. METHODS: Mononuclear cells were isolated from the spleen of OT1 mice and CD8+ T cells were differentiated in culture for 4 days with IL-2 or IL-2 plus IL-4. Cytokine production and lineage-specific transcription factors were analyzed. In vivo, anti-IL-4 was injected into sensitized CD8 KO mice prior to receiving differentiated CD8+ T cells and three consecutive days of airway allergen challenge. Airway function and inflammation were monitored. RESULTS: In the presence of IL-2, differentiated CD8+ T effector cells were exclusively IFN-gamma producers. Differentiation in the presence of IL-2 plus IL-4 followed by antigen re-stimulation resulted in CD8+ T cells that predominantly produced IL-13 rather than IFN-gamma, and was associated with changes in levels of expression of T-bet (reduced) and GATA3 (increased). IFN-gamma-producing CD8+ T effector cells adoptively transferred into sensitized CD8 KO recipients prior to challenge, converted in vivo to IL-13 producers and restored the development of AHR and inflammation, these changes were prevented by treating the recipients with anti-IL-4. CONCLUSIONS: IL-4 plays a pivotal role in the conversion of CD8+ T cells from IFN-gamma-producing to pathogenic IL-13-producing cells which mediate AHR and inflammation in sensitized and challenged animals.
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MONDAY
Involvement Of Polycyclic Aromatic Hydrocarbons In Th22/ Th17 Polarization In Allergic Diseases C. Ple1, Y. Fan1, H. Vorng1, I. Azzaoui1, S. Ait Yahia1, G. Lazennec2, B. Wallaert1,3, A. Tsicopoulos1,3; 1Pulmonary Immunity-CIIL, Lille, FRANCE, 2INSERM U844, Montpellier, FRANCE, 3Clinique des Maladies Respiratoires et Centre Hospitalier Regional et Universitaire de Lille, Lille, FRANCE. RATIONALE: Polycyclic Aromatic Hydrocarbons (PAH) derived from diesel exhausts and tobacco play an adjuvant role in allergic diseases. Aryl hydrocarbon Receptor (AhR), a transcription factor binding PAH may control IL-17A and IL-22 productions, which are increased in allergic asthmatic subjects. Therefore, PAH may contribute to Th17/Th22 polarization and promote allergic asthma. METHODS: Peripheral blood mononuclear cells (PBMCs) from non allergic and allergic subjects were stimulated with anti-CD3/anti-CD28 combined or not with purified PAH including Benzo[a]pyrene (B[a]P) or with Diesel Particulate Related Standard Reference Material (SRM 1975). IL-17A, IL-17F, CCL20 and IL-22 were measured in culture supernatants by ELISA and mRNA levels of rora, rorg, ahr and il26 were determined by qPCR. AhR involvement was analyzed by addition of CH-223191, an AhR antagonist. IL-17A and IL-22 cell origin was determined by flow cytometry. RESULTS: Without PAH, PBMCs from allergic patients secreted more IL-17A, IL-17F and IL-22 and showed more important mRNA levels of rorg than those from non allergic donors. PAH promoted IL-22 secretion but decreased IL-17A secretion, as well as rora and rorg mRNA expression in both allergic and non allergic donors. In allergic donors, B[a]P also increased il26 and decreased ahr mRNA expressions. AhR was partially involved in IL-22 secretion and IL-17A inhibition in response to B[a]P, and this whatever the donor status. CD4+ T cells, CD8+ T cells and DC were the IL-22 producing cells in response to SRM. CONCLUSION: HAP promote Th22 polarization in allergic and non allergic donors through mechanisms dependent or not on AhR.
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A Non-redundant Role of ERK1 in Th2 Cell Differentiation, Survival and Development of Asthma R. Alam1, N. Goplen1, Z. Karim1, L. Guo1, Y. Zhuang1, H. Huang1, M. M. Gorska1, E. Gelfand1, G. Pages2, J. Pouyssgur2; 1National Jewish Health, Denver, CO, 2University of Nice Sophia Antipolis, Nice, FRANCE. RATIONALE: The extracellular signal-regulated kinases 1 and 2 (ERK1 and ERK2) are important for development of asthma. ERK1 and ERK2 are functionally analogous and commonly studied together. The purpose of this study was to delineate the specific role of ERK1 in T helper cell differentiation and development of experimental asthma. METHODS: Negatively purified CD4 T cells were studied for T helper cell differentiation, function, and apoptosis using flow cytometry, ELISA, and real-time PCR. We used ERK1-/- and littermate control ERK+/+ mice to study acute and chronic asthma. RESULTS: ERK1/2 levels decreased and increased dynamically in differentiating human Th1 and Th2 cells, respectively. IL4 augmented and IL12/IFN-gamma reduced ERK1/2 expression in T cells. ERK1-/mice had reduced levels of Th2 cytokines–IL-4 and IL-5, allergen-specific IgE and allergen-induced T cell proliferation. They had decreased number of blood eosinophils, secondary to reduced IL-5 production. JunB is an ERK1/2-inducible AP1 transcription factor, which is essential for Th2 differentiation. ERK1-/- T cells had reduced expression of and short-lived JunB. Immunized ERK1-/- mice showed reduced number of CD44high Th2 memory cells. ERK1-/- CD4 T cells expressed higher levels of proapoptotic BIM and reduced levels of anti-apoptotic Mcl1. As a result the survival of CD44high Th2 cells was reduced. Finally, ERK1-/- mice were unable to mount airway inflammation and hyperreactivity (airway resistance by Flexivent) in two different mouse models of asthma–acute and chronic. CONCLUSIONS: ERK1 plays a non-redundant role in Th2 differentiation and development of experimental asthma through its effect on JunB and the apoptosis regulators–BIM and Mcl1.