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- Grindebacke, Hanna, 1977, et al.
(författare)
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Defective suppression of Th2 cytokines by CD4CD25 regulatory T cells in birch allergics during birch pollen season
- 2004
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Ingår i: Clin Exp Allergy. ; 34:9, s. 1364-72
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: CD4(+)CD25+ regulatory T cells suppress proliferation and cytokine production by human T cells both to self-antigens and exogenous antigens. Absence of these cells in human newborns leads to multiple autoimmune and inflammatory disorders together with elevated IgE levels. However, their role in human allergic disease is still unclear. OBJECTIVE: This study aimed to evaluate the capacity of CD4(+)CD25+ regulatory T cells to suppress proliferation and cytokine production outside and during birch-pollen season in birch-allergic patients relative to non-allergic controls. METHODS: CD4+ cells were obtained from blood of 13 birch-allergic patients and six non-allergic controls outside pollen season and from 10 birch-allergic patients and 10 non-allergic controls during birch-pollen season. CD25+ and CD25- fractions were purified with magnetic beads and cell fractions, alone or together in various ratios, were cultured with antigen-presenting cells and birch-pollen extract or anti-CD3 antibody. Proliferation and levels of IFN-gamma, IL-13, IL-5 and IL-10 were measured by thymidin incorporation and ELISA, respectively. Numbers of CD25+ cells were analysed by flow cytometry. RESULTS: CD4(+)CD25+ regulatory T cells from both allergics and non-allergics potently suppressed T cell proliferation to birch allergen both outside and during birch-pollen season. However, during season CD4(+)CD25+ regulatory T cells from allergic patients but not from non-allergic controls were defective in down-regulating birch pollen induced IL-13 and IL-5 production, while their capacity to suppress IFN-gamma production was retained. In contrast, outside pollen season the regulatory cells of both allergics and non-allergic controls were able to inhibit T-helper 2 cytokine production. CONCLUSION: This is the first study to show differential suppression of Th1 and Th2 cytokines, with CD4(+)CD25+ regulatory T cells from birch-pollen-allergic patients being unable to down-regulate Th2, but not Th1 responses during birch-pollen season.
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| 2. |
- Grindebacke, Hanna, 1977, et al.
(författare)
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Dynamic development of homing receptor expression and memory cell differentiation of infant CD4+CD25high regulatory T cells.
- 2009
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Ingår i: Journal of immunology (Baltimore, Md. : 1950). - : The American Association of Immunologists. - 1550-6606 .- 0022-1767. ; 183:7, s. 4360-70
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Tidskriftsartikel (refereegranskat)abstract
- Migration of CD4+CD25+FOXP3+ regulatory T cells (Treg) is important for suppressing immune responses in different tissues. Previous studies show that the majority of Treg at birth express gut homing receptor alpha(4)beta(7) and that only few express CCR4, while the reverse pattern is found in adults. The age at which homing receptor switch occurs in vivo is not known. In this study, we show, in a prospective study of human infants from birth to 3 years of age, that homing receptor switch from alpha(4)beta(7) to CCR4 commences between 1 1/2 and 3 years of age and that Treg at that age also had started their switch to a memory phenotype. The majority of naive Treg express alpha(4)beta(7) in infants but not in adults, while the majority of memory Treg express CCR4 both infants and adults. The homing receptor expression on Treg corresponds to their actual migration properties, because Treg from cord blood migrate foremost toward the gut-associated chemokine CCL25. CD4+FOXP3+ T cell numbers increase rapidly in the circulation during the first days of life indicating conversion to suppressive Treg from CD25(high) Treg precursors. These findings suggest that the gut is the primary site of Treg stimulation to exogenous Ags during the first 18 mo of life and that homing receptor switch toward a more extra-intestinal phenotype occurs thereafter.
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| 3. |
- Grindebacke, Hanna, 1977, et al.
(författare)
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Specific Immunotherapy to Birch Allergen Does not Enhance Suppression of Th2 Cells by CD4(+)CD25 (+) Regulatory T Cells During Pollen Season.
- 2009
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Ingår i: Journal of clinical immunology. - : Springer Science and Business Media LLC. - 1573-2592 .- 0271-9142. ; 29:6, s. 752-60
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: The aim of this study was to investigate the suppressive capacity of CD25(+) regulatory T cells on birch allergen-induced T-cell responses during the first birch pollen season after initiation of specific immunotherapy (SIT). METHODS: CD25(pos) and CD25(neg) T cells were purified from blood of birch-allergic SIT patients and birch-allergic controls, stimulated with birch pollen extract, and analyzed for T-cell proliferation and production of interferon gamma (IFN-gamma), interleukin (IL)-5 and IL-10. RESULTS: We show that allergen-induced proliferation and IFN-gamma production were suppressed equally well by CD25(pos) T cells from SIT patients and controls, while the IL-5 production was not suppressed by either of the groups. IL-10 levels were higher in SIT patients relative to controls only when CD25(neg) and CD25(pos) were cultured together. Furthermore, neither FOXP3 levels nor proportions of CD25(high) T cells were enhanced in SIT patients compared to allergic controls. DISCUSSION: These results suggest that the Th2-suppressive capacity of allergen-stimulated CD25(pos) Treg in vitro is not improved by SIT in spite of increased IL-10 production from T cells.
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| 4. |
- Andersson Lundell, Anna-Carin, 1976, et al.
(författare)
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Cat allergen induces proinflammatory responses by human monocyte-derived macrophages but not by dendritic cells
- 2005
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Ingår i: Allergy. ; 60:9, s. 1184-91
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The upper airway mucosa of healthy humans contains a dense network of cells with dendritic morphology of which the majority express a macrophage-like phenotype (CD14+CD64+CD68+), whereas the smaller population are immature dendritic cells (DC; CD11c+CD14-). Our aim was to study the proinflammatory response of human monocytes and in vitro-generated macrophages and DC after contact with cat allergens. METHODS: Monocyte-derived DC and monocyte-derived macrophages were exposed to cat allergen extract or Escherichia coli. Purified monocytes were stimulated with allergen extracts from cat or house dust mite (HDM) or the major allergenic protein Fel d 1 and induction of proinflammatory cytokines by monocytes was analyzed before and after blocking CD14. RESULTS: We show that cat allergen extract induced tumor necrosis factor (TNF) and interleukin (IL)-6 production by CD14-positive macrophages but not by CD14-negative DC. Moreover, monocytes produced significantly higher levels of TNF in response to cat allergens than in response to HDM allergens. We observed no differences in levels of TNF and IL-6 from either macrophages or monocytes after exposure to cat allergen when comparing healthy and cat-allergic individuals. Finally, the proinflammatory cytokine production from monocytes in response to cat allergen extract but not to HDM allergen was significantly reduced by blocking CD14. CONCLUSION: These results indicate that closely related innate immune cells from the myeloid lineage respond differentially to cat allergen extract and that the pattern-recognition receptor CD14 might be one of the mediators involved in the inflammatory responses to inhalant allergens.
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| 5. |
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| 6. |
- Grindebacke, Hanna, 1977
(författare)
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Phenotype and function of CD25+ regulatory T cells in infants and adults
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Active suppression by CD4+CD25+FOXP3+ regulatory T cells (Treg) is essential for the maintenance of peripheral tolerance to both self antigens and environmental antigens. Absence of these cells in human newborns leads to autoimmune and inflammatory disorders as well as allergic disease. Thus, Treg are probably necessary for down-regulating autoimmune as well as allergic immune reactions. The aim of this thesis was to examine if Treg from birch pollen-allergic patients were able to suppress birch pollen-induced proliferation and cytokine production and if their suppressive function was affected following specific immunotherapy (SIT) against birch pollen allergy. Moreover, it aimed to describe the expression of FOXP3, homing receptors and maturation markers on Treg at various time points during the first 3 years of life compared with the expression seen in adults. We found that pollen-allergic patients and non-allergic controls had similar proportions of Treg cells in the circulation and that Treg were equally able to potently suppress birch pollen-induced proliferation and production of IFN-γ. However, Treg cells isolated during birch pollen-season from allergic patients were not able to down-regulate birch-pollen induced production of IL-13 and IL-5, in contrast to those from non-allergic controls. Likewise, Treg from birch pollen-allergic patients who had undergone SIT for 6 months were unable to suppress IL-5 production, while their ability to suppress proliferation and IFN-γ production was retained and similar as in untreated allergic controls. Of note, we found that IL-10 was produced at higher levels in SIT patients than controls, but only when CD25neg cells and Treg were cultured together and not when the CD25neg or Treg cells were cultured separately. This indicates that both Treg and CD25neg T cells are important and need to be present for an increased production of IL-10 to occur after SIT. When examining the expression of FOXP3, homing receptors and maturation markers on Treg in infants we observed a rapid increase in the proportion of Treg in the circulation during the first days of life, indicating conversion to suppressive Treg from CD25high Treg precursors. An appropriate localisation of these cells is essential for their ability to suppress immune responses and their migration to different tissues is determined by homing receptors. We found that that a homing receptor switch from the gut homing receptor 4β7 to the extra-intestinal homing receptor CCR4 on Treg started as late as between 18 months and 3 years of age and was associated with maturation of the Treg. Moreover, the homing receptor expression on Treg corresponded to their actual migration properties, since Treg from cord blood migrated foremost towards the gut-associated chemokine CCL25. In conclusion, our results indicate that Treg from allergic individuals are unable to suppress Th2 responses, but not Th1 responses, during birch-pollen season and that SIT is unable to restore the ability of Treg to suppress Th2 responses in vitro in spite of an increased production of IL-10. Moreover, Treg cells in infants up to 18 months of age express 47 and migrate towards gut-homing chemokines, while at 3 years the cells have started to mature and to switch into extra-intestinal homing receptors.
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