Protective roles of STAT6 in basophil-dependent prurigo-like reactions

Protective roles of STAT6 in basophil-dependent prurigo-like reactions

e70 JSID Abstracts / Journal of Dermatological Science 69 (2013) e47–e93 intermediate expression levels of ␥␦ T cell receptor. These findings indicat...

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e70

JSID Abstracts / Journal of Dermatological Science 69 (2013) e47–e93

intermediate expression levels of ␥␦ T cell receptor. These findings indicate that dermal v␥4-positive ␥␦T cells migrate to the epidermis and produce IL-17A. Finally, to clarify the impact of IL-17A on keratinocytes, we tape-stripped and injected IL-17A into the ear of BALB/c mice. We found that the expression level of TSLP in keratinocytes was upregulated by IL-17A. Taken together, our results suggest that dermal ␥␦T cells migrating into the epidermis are the essential sources of IL-17A in the skin, and that IL-17A promotes Th2 induction in the murine AD models via TSLP induction in keratinocytes. http://dx.doi.org/10.1016/j.jdermsci.2012.11.515 P10-08[C07-05] Generation of B7H1-expressing CD11b + Gr1 + myeloid derived suppressor cells (MDSCs) during immune-modulatory therapy for B16F10 melanoma Taku Fujimura ∗ , Yumi Kambayashi, Setsuya Aiba Department of Dermatology, Tohoku University Graduate School of Medicine, Sendai, Japan Myeloid derived suppressor cells (MDSC) comprise a heterogeneous population of cells (CD11b + , Gr-1 + ) that can be found in tumor-bearing hosts. We previously reported that MDSC suppress the activity of T cells together with Tregs through B7H1mediated pathways. To investigate the MDSC during melanoma treatment, we subcutaneously injected mice with 2 × 105 B16F10 and administered topical 5% imiquimod cream (IQM) with or without i.p. injection of Dacarbazine (Dac). FACS analysis revealed that B7H1 was significantly augmented both on splenic (s-)MDSC and tumor-derived (t-)MDSC from IQM-treated mice. In contrast, the expression of B7H1 was normalized on s-MDSC from IQM/Dac-treated mice, though the B7H1 was still augmented on t-MDSC. Interestingly, in parallel with the expression of B7H1 on sMDSC, the administration of IQM/Dac significantly suppressed the growth of B16F10 melanoma. Next, to investigate the mechanisms responsible for the increased levels of B7H1 by IQM, we isolated CD11c + cells or CD11b + cells and examined the expression of IL12 family mRNA using real-time PCR. The administration of IQM significantly increased p35 on CD11c, and p28 and EBI3 on CD11b. CD11b from tumor-bearing mice expressed IL-27R (gp130/WSX1), indicating that B7H1 on CD11b might be augmented by IL-27. To investigate the therapeutic effects of blocking B7H1 molecules in vivo, we administered B7H1 antibody to B16F10-bearing mice. The administration of B7H1 Ab significant suppressed the B16F10 in a dose-dependent manner. Our results suggest that s-MDSC and t-MDSC from B16F10 bearing mice express B7H1 molecules that are augmented by topical IMQ, and normalized together with Dac in the s-MDSCs, which induces the therapeutic effect of IMQ based therapy. http://dx.doi.org/10.1016/j.jdermsci.2012.11.516

P10-09[C07-06] Protective roles of STAT6 in basophil-dependent prurigo-like reactions Takashi Hashimoto 1,∗ , Takahiro Satoh 1,2 , Hiroo Yokozeki 2 1

Department of Dermatology, National Defense Medical College, Saitama, Japan 2 Department of Dermatology, Tokyo Medical and Dental University, Tokyo, Japan Prurigo is a common skin disease characterized by urticarial papules and/or nodules with severe itching. While the mechanisms underlying prurigo have yet to be determined, our previous study demonstrated that repeated administration of antigens in IgE-transgenic mice induced prurigo-like skin lesions. The present study investigated immunological events in a murine model of prurigo reactions. IgE-transgenic mice received intradermal injections of 2,4,6-trinitrophenyl ovalbumin (TNP-OVA) into dorsal skin on days 1, 4, and 7, resulting in the development of persistent nodular skin lesions. Histopathologically, marked hyperkeratosis with irregular acanthosis was accompanied by a dense cellular infiltrate comprising mononuclear cells, eosinophils, basophils, and increased numbers of mast cells. Marked sprouting of PGP9.5(+) nerve fibers in the epidermis was also observed. Local cytokine profiles were characterized by elevated levels of interleukin (IL)-4, IL-13, IL-17, IL-22, IL-31, and nerve growth factor. In vivo depletion of basophils resulted in alleviation of skin reactions, indicating the basophil-dependent nature of this inflammation. Nuclear translocation of pSTAT6 and pSTAT3 was also observed in epidermal keratinocytes. C57BL/6 mice also developed prurigo-like lesions when repeatedly challenged with TNP-OVA in conjunction with TNP-IgE. Unexpectedly, STAT6(-/-) mice showed significant exacerbation of skin reactions compared with wild-type C57BL/6 mice. Consistent with this finding, local administration of STAT6 small interfering RNA resulted in exacerbated skin inflammation. Th2 immunity mediated by STAT6 thus appears to play protective roles and therapies targeting Th2-type cytokines may risk aggravating prurigo reactions. http://dx.doi.org/10.1016/j.jdermsci.2012.11.517 P10-10 Establishment of a method to quantify the specific IgE against sweat antigen in sera of patients with atopic dermatitis Makiko Hiragun 1,∗ , Kaori Ishii 1 , Takaaki Hiragun 1 , Yuhki Yanase 1 , Hidenori Suzuki 2 , Shoji Mihara 1 , Michihiro Hide 1

1

Department of Dermatology, Integrated Health Sciences, Institute of Biomedical & Health Sciences, Hiroshima University, Hiroshima, Japan 2 Faculty of Human Science, Hiroshima Bunkyo Women’s University, Hiroshima, Japan Background: Sweat is a major aggravating factor of atopic dermatitis (AD) and approximately 80% of patients with AD reveal type I-hypersensitivity against sweat and semi-purified sweat antigen (QRX). To diagnose the sweat allergy, we routinely perform the basophil histamine release test (HRT). However, HRT needs fresh blood cells of patients and its results are qualitative rather than quantitative. In this study, to overcome the disadvantages of HRT, we established the enzyme-linked immunosorbent assay (ELISA) to measure specific IgE against sweat antigen by using sera of patients with AD. Methods: The lymph node cells, which were from Balb/c mice immunized by QRX, were fused with a myeloma cell line. Clones of the hybridomas were screened by the neutralization ability against