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- Oefner, Carolin M., et al.
(författare)
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Tolerance induction with T cell-dependent protein antigens induces regulatory sialylated IgGs
- 2012
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Ingår i: Journal of Allergy and Clinical Immunology. - : Elsevier BV. - 1097-6825 .- 0091-6749. ; 129:6, s. 1647-1647
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Tidskriftsartikel (refereegranskat)abstract
- Background: Under inflammatory conditions, T cell-dependent (TD) protein antigens induce proinflammatory T-and B-cell responses. In contrast, tolerance induction by TD antigens without costimulation triggers the development of regulatory T cells. Under both conditions, IgG antibodies are generated, but whether they have different immunoregulatory functions remains elusive. Objective: It was shown recently that proinflammatory or anti-inflammatory effector functions of IgG molecules are determined by different Fc N-linked glycosylation patterns. We sought to examine the Fc glycosylation and anti-inflammatory quality of IgG molecules formed on TD tolerance induction. Methods: We administered chicken ovalbumin (OVA) with or without costimulus to mice and analyzed OVA-reactive IgG Fc glycosylation. The anti-inflammatory function of differentially glycosylated anti-OVA IgGs was further investigated in studies with dendritic cell cultures and in an in vivo model of allergic airway disease. Additionally, we analyzed the Fc glycosylation pattern of birch pollen-reactive serum IgGs after successful allergen-specific immunotherapy in patients. Results: Stimulation with TD antigens under inflammatory conditions induces plasma cells expressing low levels of alpha 2,6-sialyltransferase and producing desialylated IgGs. In contrast, plasma cells induced on tolerance induction did not downregulate alpha 2,6-sialyltransferase expression and secreted immunosuppressive sialylated IgGs that were sufficient to block antigen-specific T- and B-cell responses, dendritic cell maturation, and allergic airway inflammation. Importantly, successful specific immunotherapy in allergic patients also induced sialylated allergen-specific IgGs. Conclusions: Our data show a novel antigen-specific immunoregulatory mechanism mediated by anti-inflammatory sialylated IgGs that are formed on TD tolerance induction. These findings might help to develop novel antigen-specific therapies for the treatment of allergy and autoimmunity. (J Allergy Clin Immunol 2012;129:1647-55.)
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| 2. |
- von Eyss, Björn, et al.
(författare)
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The SNF2-like helicase HELLS mediates E2F3-dependent transcription and cellular transformation.
- 2012
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Ingår i: EMBO Journal. - : Nature Publishing Group. - 0261-4189 .- 1460-2075. ; 31:4, s. 972-985
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Tidskriftsartikel (refereegranskat)abstract
- The activating E2F-transcription factors are best known for their dependence on the Retinoblastoma protein and their role in cellular proliferation. E2F3 is uniquely amplified in specific human tumours where its expression is inversely correlated with the survival of patients. Here, E2F3B interaction partners were identified by mass spectrometric analysis. We show that the SNF2-like helicase HELLS interacts with E2F3A in vivo and cooperates with its oncogenic functions. Depletion of HELLS severely perturbs the induction of E2F-target genes, hinders cell-cycle re-entry and growth. Using chromatin immmunoprecipitation coupled to sequencing, we identified genome-wide targets of HELLS and E2F3A/B. HELLS binds promoters of active genes, including the trithorax-related MLL1, and co-regulates E2F3-dependent genes. Strikingly, just as E2F3, HELLS is overexpressed in human tumours including prostate cancer, indicating that either factor may contribute to the malignant progression of tumours. Our work reveals that HELLS is important for E2F3 in tumour cell proliferation.
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