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Recruitment to the local tissue and alerted phenotype are the hallmarks of basophils in chronic urticaria (CU). Chemokine receptors such as chemokine (C-C motif) receptor 4 (CCR4) or CCR8 have been studied in skin diseases, e.g., atopic dermatitis, but not in CU. In this study, we aimed to define CU's basophil homing potential and receptor profile and the effect of Omalizumab treatment on these. Unstimulated and activated (anti-IgE, fMLP, C5a, and Substance P) whole blood basophils from 11 Omalizumab-treated CU patients and 10 healthy subjects were investigated with flow cytometry. Unstimulated basophils in CU showed higher expression of the skin-associated (CCR8) and scavenger (CCX-CKR) receptors and lower expression of the lung-associated (CCR3) receptor in contrast to healthy ones. IgE-mediated activation increased the percentage of CCR8 and CCX-CKR in CU compared to healthy group and elevated the expression of the lung-associated chemokine receptor, XCR1, in all groups. A trend of augmented expression of the coagulation cascade (CD87) and fMLP (FPR1) receptors was seen on basophils in CU, while a tendency of reduced expression was seen for itch (IL-31RA) and immunotolerance (CD109) receptors. fMLP and C5a increased the expression of CCR4, CCR8, CCX-CKR, and CD87 and decreased CCR2 and CCR3, though no changes between the groups were found. In conclusion, CU basophils exhibit skin-homing potential amplified by IgE-mediated stimulation.

BACKGROUND: Patch testing is the gold standard for identifying culprit allergens in allergic contact dermatitis; however, it's laborious and positive reactions are difficult to quantitate. Development of complementary in vitro tests is, therefore, of great importance.OBJECTIVES: This study aimed to improve the in vitro lymphocyte proliferation test (LPT) to detect allergic responses to nickel, cobalt and chromium.METHODS: Twenty-one metal-allergic patients with a positive patch test to nickel (16), cobalt (8) and chromium (3) and thirteen controls were included. All were tested by a flow cytometric LPT.RESULTS: Metal-reactive cells were identified as Th cells with high expression of the memory marker CD45RO. Skin-homing (CLA+ ) nickel-reactive memory Th (Thmemhi ) cells identified individuals with a positive patch test for nickel with 100 % sensitivity [81%,100%] and 92% specificity [67%,100%]. Moreover, cobalt-specific Thmemhi cells expressing CCR6 identified patients with a positive patch test for cobalt with 63% sensitivity [31%,86%] and 100% specificity [77%,100%]. In chromium allergic individuals, Chromium-reactive Thmemhi cells tended to increased CLA and CCR6 expression.CONCLUSION: Metal-reactive Th cells with high expression CD45RO and co-expression of CLA and CCR6 improved the LPT, making it an attractive supplement to the patch test. This article is protected by copyright. All rights reserved.

BACKGROUND: The pathology of allergic diseases involves type 2 immune cells, such as Th2, ILC2, and basophils exerting their effect by production of IL-4, IL-5, and IL-13. However, surface receptors that are specifically expressed on type 2 immune cells are less well documented. The aim of this investigation was to identify surface markers associated with type 2 inflammation.METHODS: Naïve human CD4(+) T-cells were short-term activated in the presence or absence of IL-4, and analysed for expression of >300 cell-surface proteins. Ex vivo isolated PBMCs from peanut and non-allergic allergic subjects, were stimulated (14-16h) with peanut extract to detect peanut-specific CD4(+) CD154(+) T-cells. Biopsies were obtained for transcriptomic analysis from healthy controls and patients with extrinsic or intrinsic atopic dermatitis and psoriasis.RESULTS: Expression analysis of >300 surface proteins enabled identification of IL-4 up-regulated surface proteins, such as CD90, CD108, CD109, and CD200R (CD200R1). Additional analysis of in vitro differentiated Th0, Th1, and Th2 cultures, identified CD200R as up-regulated on Th2 cells. From ex vivo isolated PBMCs, we found high expression of CD200R on Th2 and ILC2 cells and basophils. In peanut-allergic subjects the peanut-specific Th2 (CD154(+) CRTh2(+) ) cells expressed more CD200R than the non-allergen specific Th2 (CD154(-) CRTh2(+) ) cells. Moreover, co-staining of CD161 and CD200R identified peanut-specific highly differentiated IL-4(+) IL-5(+) Th2 cells. Finally, transcriptomic analysis revealed up-regulation of CD200R in lesional skin from subjects with an extrinsic atopic dermatitis phenotype compared to healthy skin.CONCLUSION: These results indicate that CD200R expression strongly correlates with Th2 pathology; though, the mechanism is as yet elusive. This article is protected by copyright. All rights reserved.

In atopic dermatitis (AD), the inflammatory response between skin infiltrating T cells and keratinocytes is fundamental to the development of chronic lesional eczema. The aim of this study was to investigate whether skin-derived T cells from AD patients could induce an inflammatory response in mice through keratinocyte activation and consequently cause development of eczematous lesions. Punch biopsies of lesional skin from AD patients were used to establish skin-derived T cell cultures and which were transferred into NOD.Cg-Prkd(scid) Il2rg(tm1Sug) /JicTac (NOG) mice. We found that subcutaneous injection of the human AD skin-derived T cells resulted in migration of the human T cells from subcutis to the papillary dermis followed by development of erythema and edema in the mouse skin. Furthermore, the human T cells induced a transient proliferative response in the mouse keratinocytes shown as increased numbers of Ki-67(+) keratinocytes and increased epidermal thickness. Out of six established AD skin-derived T cell cultures, two were superior at inducing a skin reaction in the mice, and these cultures were found to contain >10% CCR10(+) T cells compared to <2% for the other cultures. In comparison, blood -derived in vitro differentiated Th2 cells only induced a weak response in a few of the mice. Thus, we conclude that human AD skin-derived T cells can induce a reaction in mouse skin through induction of a proliferative response in the mouse keratinocytes. This article is protected by copyright. All rights reserved.

BACKGROUND. IgE-mediated activation of mast cells has been reported to induce the release of tumour necrosis alpha (TNF-?), which may display autocrine effects on these cells by inducing the generation of the tissue remodelling protease matrix metalloproteinase-9 (MMP-9). While mast cells and basophils have been shown to express complementary and partially overlapping roles, it is not clear whether a similar IgE/TNF-?/MMP-9 axis exists in the human basophil. The purpose of this study was thus to investigate whether IgE-mediated activation of human basophils induces TNF-? and MMP-9 release. METHODS. Human peripheral blood mononuclear cells (PBMC), isolated basophils and monocytes were stimulated up to 21 h with anti-IgE. Mediator releases were assessed by ELISA, and surface expressions of mediators were detected by flow cytometry. Upregulation of cytokine production was detected by Western blot and polymerase chain reaction (PCR). RESULTS. IgE-mediated activation of basophils induced the synthesis and release of both TNF-? and MMP-9 from PBMC. In contrast, IgE-mediated activation of purified basophils induced the release and cellular expression of TNF-? but not MMP-9. Isolated monocytes did not release MMP-9 upon anti-IgE stimulation, but MMP-9 release was induced by stimulating monocytes with supernatants from activated basophils, and this release was inhibited by anti-TNF-? neutralizing antibodies. CONCLUSION. Our results strongly indicate that human basophils release TNF-? following IgE-dependent activation and that this cytokine subsequently stimulates MMP-9 release from monocytes. These findings support a direct involvement of basophils in inflammation as well as suggesting a role for the basophil in tissue remodelling.

The FAST project (Food Allergy Specific Immunotherapy) aims at the development of safe and effective treatment of food allergies, targeting prevalent, persistent and severe allergy to fish and peach. Classical allergen-specific immunotherapy (SIT), using subcutaneous injections with aqueous food extracts may be effective but has proven to be accompanied by too many anaphylactic side-effects. FAST aims to develop a safe alternative by replacing food extracts with hypoallergenic recombinant major allergens as the active ingredients of SIT. Both severe fish and peach allergy are caused by a single major allergen, parvalbumin (Cyp c 1) and lipid transfer protein (Pru p 3), respectively. Two approaches are being evaluated for achieving hypoallergenicity, i.e. site-directed mutagenesis and chemical modification. The most promising hypoallergens will be produced under GMP conditions. After pre-clinical testing (toxicology testing and efficacy in mouse models), SCIT with alum-absorbed hypoallergens will be evaluated in phase I/IIa and IIb randomized double-blind placebo-controlled (DBPC) clinical trials, with the DBPC food challenge as primary read-out. To understand the underlying immune mechanisms in depth serological and cellular immune analyses will be performed, allowing identification of novel biomarkers for monitoring treatment efficacy. FAST aims at improving the quality of life of food allergic patients by providing a safe and effective treatment that will significantly lower their threshold for fish or peach intake, thereby decreasing their anxiety and dependence on rescue medication.

The IL-1 family members IL-1ß, IL-18, and IL-33 are potent cytokines in relationship to amplifying the CD4(+) T cell cytokine production. To evaluate their impact on in vitro-differentiated human Th1 and Th2 cultures, such cultures were established from naive T cells, purified from healthy blood donors, and reactivated in the presence of IL-1ß, IL-18, or IL-33. Interestingly, we observe modifying responses in Th1 and Th2 cultures induced by IL-18 or IL-33 but not by IL-1ß, both contributing to amplify production of IL-5, IL-13, and IFN-¿. IL-18 or IL-33 stimulation of Th1 cultures resulted in increased IFN-¿ and IL-13 production concurrent with reduced IL-10 gene transcription and secretion even though Th1 cultures, in contrast to IL-18Ra, had low ST2L expression. Furthermore, adding IL-18 to Th1 cultures promoted Tbet mRNA expression and production. Th2 cultures stimulated with IL-18 or IL-33 had an increased IL-5 secretion. Interestingly, E4BP4 gene expression and the percentage of E4BP4(+) cells of the recently shown IL-10 transcriptional regulator E4BP4 correlated with IL-10 gene expression and protein secretion in Th1 cultures. Taken together, we report that the IL-1 family "alarmins" IL-18 and IL-33 in addition to amplifying both Th1- and Th2-associated cytokines block production of the regulatory cytokine IL-10 in Th1 cultures.

Background IL-9 has been suggested to play an important role in chronic inflammation due to its effect on remodeling and cell recruitment. Since basophils can be found in inflamed tissue, we wanted to test if human basophils are capable of secreting IL-9 under the influence of growth or tissue factors like IL-3 or IL-33, respectively. Methods Basophils, purified from buffy coat blood by negative selection (purity > 95%), were cultured for 24 hours in RPMI culture medium (1x106 cells/ml) supplemented with 5% human serum, and IL-3 (10 ng/ml) and/or IL-33 (50 ng/ml). The cells were then analysed by FACS for ST2 expression where basophils were gated as FceRIa+CD3-CD14-CD19-CD56-. The supernatant was tested for IL-9 using a multiplex magnetic bead assay. Results Human basophils have recently been described to express the IL-33 receptor ST2. In agreement with previous findings, our results showed increased surface expression of ST2 on basophils stimulated with IL-3 for 24 h, whereas IL-33 stimulation did not influence surface expression of its receptor. Nevertheless, basophils stimulated with IL-33 released IL-9 at a level comparable to what was found when stimulating with IL-3. Moreover, there was a marked synergy between IL-3 and IL-33 on the IL-9 release. Conclusion To our knowledge, this is the first report that human basophils secrete IL-9. A strong synergy between IL-3 and IL-33 was found on the IL-9 induction, likely to be explained by the IL-3 upregulated ST2 expression.

IL-33, an IL-1 family member and ligand for the IL-1 receptor-related protein ST2, has been associated with induction of Th2 cytokines such as IL-4, IL-5, and IL-13. Here, we report that IL-33 can initiate IL-9 protein secretion in vitro in human CD4+ T cells and basophils isolated from peripheral blood. TGF-β has been described as a critical factor for IL-9 induction in Th2 cells; however, we found that TGF-β also induces co-production of IL-9 in purified, naïve (>99%) CD4(+)CD45RA(+)CD45RO(-)CD25(-) T cells differentiated towards a Th1 profile. Subsequently, it was demonstrated that TGF-β is important, although not an absolute requirement, for IL-9 production in CD4+ T cells. IL-9 production by purified (>95%) human basophils, cultured for 24 h with IL-3 or IL-33, was found, with a strong synergy between the two, likely to be explained by the IL-3 upregulated ST2 expression. Collectively, these data indicate that barrier functioning cells are important for the regulation of IL-9 production by immune cells in inflamed tissue.

Inför folkomröstningen om införandet av Euron och deltagande i tredje steget av den ekonomiska och monetära unionen 14 september 2003 debatterades de automatiska stabilisatorerna livligt. En fördel som framfördes var deras snabba reaktion vid konjunkturförändringar. Studeras stabilisatorerna en aning närmare är detta antagandet inte helt uppenbart. I debatten nämndes också stabilisatorerna som en vital del av stabiliseringspolitiken men några empiriska bevis på storleken presenterades aldrig. Jag bestämde mig därför att gå till grunden med frågan om de automatiska stabilisatorerna för att undersöka om de var tillräckliga för ett EMU medlemskap. Mitt mål var att försöka ställa upp en effektivitetsansats. Jag satte därför upp fyra kriterier med egenskaper som jag tyckte var viktiga för automatiska stabilisatorer. 1. Stor kontracyklisk påverkan på den aggregerade efterfrågan 2. Verka med mindre tidsfördröjning än diskretionär finanspolitik 3. Minimal påverkan på arbetsutbudet 4. Små destabiliserande egenskaper vid extrema makroekonomiska förhållanden Undersökningen bestod sedan i att undersöka huruvida dessa kriterier var uppfyllda.