| 1. |
- Boij, Roland, et al.
(författare)
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Regulatory T-cell Subpopulations in Severe or Early-onset Preeclampsia
- 2015
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Ingår i: American Journal of Reproductive Immunology. - : WILEY-BLACKWELL. - 1046-7408 .- 1600-0897. ; 74:4, s. 368-378
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Tidskriftsartikel (refereegranskat)abstract
- Problem A deficiency in regulatory T (Treg) cells causing reduced immune regulatory capacity has been proposed in preeclampsia. Objective Utilizing recent advances in flow cytometry phenotyping, we aimed to assess whether a deficiency of Treg subpopulations occurs in preeclampsia. Method of study Six-color flow cytometry was used for Treg phenotyping in 18 preeclamptic women (one early-onset, one severe and 16 both), 20 women with normal pregnancy, and 20 non-pregnant controls. Results No differences were found in major Treg populations including CD127(low)CD25(+)/CD127(ow)FOXP3(+), resting (FOXP3(dim)CD45RA(+)), and activated (FOXP3(bright)CD45RA(-)) Treg cells, whereas preeclamptic women showed increased CTLA-4(+) and CCR4(+) proportions within resting/activated Treg populations. Corticosteroid treatment prior to blood sampling (n = 10) affected the distribution of Treg populations. Conclusions Although we found no major alterations in circulating Treg frequencies, differences in CTLA-4(+) and CCR4(+) frequencies suggest a migratory defect of Treg cells in preeclampsia. Corticosteroid treatment should be taken into account when evaluating Treg cells.
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| 2. |
- Carleo, Ilaria, et al.
(författare)
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The Multiplanet System TOI-421*
- 2020
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Ingår i: Astronomical Journal. - : American Astronomical Society. - 1538-3881 .- 0004-6256. ; 160:3
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Tidskriftsartikel (refereegranskat)abstract
- We report the discovery of a warm Neptune and a hot sub-Neptune transiting TOI-421 (BD-14 1137, TIC 94986319), a bright (V = 9.9) G9 dwarf star in a visual binary system observed by the Transiting Exoplanet Survey Satellite (TESS) space mission in Sectors 5 and 6. We performed ground-based follow-up observations-comprised of Las Cumbres Observatory Global Telescope transit photometry, NIRC2 adaptive optics imaging, and FIbre-fed Echelle Spectrograph, CORALIE, High Accuracy Radial velocity Planet Searcher, High Resolution echelle Spectrometer, and Planet Finder Spectrograph high-precision Doppler measurements-and confirmed the planetary nature of the 16 day transiting candidate announced by the TESS team. We discovered an additional radial velocity signal with a period of five days induced by the presence of a second planet in the system, which we also found to transit its host star. We found that the inner mini-Neptune, TOI-421 b, has an orbital period of P-b = 5.19672 +/- 0.00049 days, a mass of M-b = 7.17 +/- 0.66 M-circle plus, and a radius of R-b = R-circle plus, whereas the outer warm Neptune, TOI-421 c, has a period of P-c = 16.06819 +/- 0.00035 days, a mass of M-c = 16.42(-1.04)(+1.06)M(circle plus), a radius of R-c = 5.09(-0.15)(+0.16)R(circle plus), and a density of rho(c) = 0.685(-0.072)(+0.080) cm(-3). With its characteristics, the outer planet (rho(c) = 0.685(-0.0072)(+0.080) cm(-3)) is placed in the intriguing class of the super-puffy mini-Neptunes. TOI-421 b and TOI-421 c are found to be well-suited for atmospheric characterization. Our atmospheric simulations predict significant Ly alpha transit absorption, due to strong hydrogen escape in both planets, as well as the presence of detectable CH4 in the atmosphere of TOI-421 c if equilibrium chemistry is assumed.
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| 3. |
- Hedman Hjorth, Maria, et al.
(författare)
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Impaired CD4+ and CD8+ T cell phenotype and reduced chemokine secretion in recent-onset type 1 diabetic children
- 2008
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Ingår i: Clinical and Experimental Immunology. - : Oxford University Press (OUP). - 0009-9104 .- 1365-2249. ; 153:3, s. 360-368
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Tidskriftsartikel (refereegranskat)abstract
- Although the role of the T cell-mediated autoimmune reaction in type 1 diabetes (T1D) is conclusive, studies including data from human circulating CD4+ and CD8+ lymphocytes subsets during the disease onset and posterior development are scarce. Further, chemokines and chemokine receptors are key players in the migration of pathogenic T cells into the islets of NOD mice developing T1D, but few studies have investigated these markers in human T1D patients. We studied the expression of T helper 1 (Th1) and Th2 associated chemokine receptors, and the two isoforms of CD45 leukocyte antigen on CD4+ and CD8+ lymphocytes from T1D and healthy children, as well as the secretion of chemokines in cell supernatants in peripheral blood mononuclear cells. Our results showed increased expression of CCR7 and CD45RA, and reduced CD45RO on CD8+ cells among recent-onset T1D patients. The percentages of CD4+ cells expressing CXC chemokine receptor 3 (CXCR3), CXCR6 and CCR5, and the secretion of interferon-γ-induced protein-10, monocyte chemoattractant protein-1, macrophage inflammatory protein (MIP)-1a and MIP-1β was lower among diabetics. Low expression of Th1-associated receptors and secretion of chemokines, together with an increased amount of CD8+ cells expressing CD45RA and CCR7 in T1D patients therefore might represent suboptimal Th function in T1D, leading to impaired T cytotoxic (Tc) responses or alternatively reflect a selective recruitment of Th1 cells into the pancreas.
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| 4. |
- Hedman Hjorth, Maria, 1978-, et al.
(författare)
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Nicotinamide reduces high secretion of IFN-γ in high-risk relatives even though it does not prevent type 1 diabetes
- 2006
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Ingår i: Journal of Interferon and Cytokine Research. - : Mary Ann Liebert Inc. - 1079-9907 .- 1557-7465. ; 26:4, s. 207-213
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Tidskriftsartikel (refereegranskat)abstract
- Type 1 diabetes (T1D) is an autoimmune disease suggested to be of a T helper (Th)1-like origin. This study aimed to investigate the Th1-like and Th2-like profile in high-risk individuals during the prediabetic phase and the immunologic effect of treatment with nicotinamide. High-risk first-degree relatives of T1D patients participating in the European Nicotinamide Diabetes Intervention Trial (ENDIT) were treated with either nicotinamide or placebo. Peripheral blood mononuclear cells (PBMC) were obtained during the prediabetic phase and close to the onset of manifest T1D and from nondiabetic high-risk individuals. Using the sensitive enzyme-linked immunospot (ELISPOT) technique to distinguish Th1-like from Th2-like lymphocytes, secretion of interferon-γ (IFN-γ) and interleukin-4 (IL-4) was analyzed from PBMCs spontaneously and after in vitro stimulation with the diabetes-associated autoantigens, glutamic acid decarboxylase 65 (GAD65, protein and peptide, aa 247-279), recombinant tyrosine phosphatase (IA-2), and heat shock protein (HSP, aa 437-460). High-risk individuals showed high spontaneous as well as autoantigen-induced IFN-γ secretion. Secretion of IFN-γ and the IFN-γ/IL-4 ratio, induced by autoantigens, decreased in individuals developing T1D (p < 0.05), whereas nondiabetic individuals showed an increased IL-4 response (p < 0.05). Thus, a Th1-dominated cytokine profile observed in high-risk individuals inclined toward a diagnosis of diabetes. Nicotinamide caused decreased spontaneous (p = 0.05) and in vitro autoantigen-induced IFN-γ secretion (p < 0.05) and may play a role in immune regulation, even though it has not been shown to prevent T1D. © Mary Ann Liebert, Inc.
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| 5. |
- Hjorth, Maria, et al.
(författare)
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GAD-alum treatment induces GAD(65)-specific CD4(+)CD25(high)FOXP3(+) cells in type 1 diabetic patients
- 2011
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Ingår i: CLINICAL IMMUNOLOGY. - : Elsevier Science B.V., Amsterdam. - 1521-6616. ; 138:1, s. 117-126
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Tidskriftsartikel (refereegranskat)abstract
- Type 1 diabetes results from autoimmune destruction of insulin producing pancreatic beta-cells. We have shown that treatment with alum-formulated glutamic acid decarboxylase 65 (GAD-alum) preserved residual insulin secretion and induced antigen-specific responses in children with recent onset type 1 diabetes. The aim of this study was to further investigate the immunomodulatory effect of GAD-alum, focusing on CD4(+)CD25(high) cells and their association to cytokine secretion. Samples obtained 21 and 30 months after the initial injection of GAD-alum or placebo were included in the present study. GAD(65)-stimulation enhanced the percentage of CD4(+)CD25(high)FOXP3(+) cells, but reduced the percentage of CD4(+)CD25(+) cells, in samples from the GAD-alum treated group. Further, the GAD(65)-induced secretion of IL-5, -10, and -13 correlated with the expression of CD4(+)CD25(high)FOXP3(+) cells, but inversely with CD4(+)CD25(+) cells. These new data suggest that GAD-alum treatment induced GAD(65)-specific T cells with regulatory features.
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| 6. |
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| 7. |
- Hjorth, Maria, et al.
(författare)
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GAD-alum treatment induces GAD65-specific CD4+CD25highFOXP3+ cells in type 1 diabetic patients.
- 2011
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Ingår i: Clinical Immunology. - : Elsevier. - 1521-6616 .- 1521-7035. ; 138:1, s. 117-126
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Tidskriftsartikel (refereegranskat)abstract
- Type 1 diabetes results from autoimmune destruction of insulin producing pancreatic β-cells. We have shown that treatment with alum-formulated glutamic acid decarboxylase 65 (GAD-alum) preserved residual insulin secretion and induced antigen-specific responses in children with recent onset type 1 diabetes. The aim of this study was to further investigate the immunomodulatory effect of GAD-alum, focusing on CD4+CD25high cells and their association to cytokine secretion. Samples obtained 21 and 30 months after the initial injection of GAD-alum or placebo were included in the present study. GAD65-stimulation enhanced the percentage of CD4+CD25highFOXP3+ cells, but reduced the percentage of CD4+CD25+ cells, in samples from the GAD-alum treated group. Further, the GAD65-induced secretion of IL-5, -10, and -13 correlated with the expression of CD4+CD25highFOXP3+ cells, but inversely with CD4+CD25+ cells. These new data suggest that GAD-alum treatment induced GAD65-specific T cells with regulatory features.
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| 8. |
- Hjorth, Maria, 1978-
(författare)
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Immunological profile and aspects of immunotherapy in type 1 diabetes
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Type 1 diabetes (T1D) is a chronic, autoimmune disease caused by a T cell mediated attack on the insulin producing pancreatic ß-cells. Even though reasonable quality of life can be acquired with modern insulin therapy, prevention of acute and late serious complications is facilitated by preservation of residual insulin secretion. Preventing β-cell destruction is therefore an important goal of T1D therapy. Characterisation of immunological changes in the course of T1D is essential for understanding the underlying pathogenic mechanisms and for evaluating the efficacy of therapeutic intervention. This thesis aimed to study the immune profile in individuals at increased risk of T1D and in patients diagnosed with the disease. In addition, the immunological effects of treatment with the B vitamin, Nicotinamide, and by antigen-specific immunotherapy using GAD65, have been studied in high-risk individuals and in T1D patients, respectively.We have found that individuals at high risk of T1D had an increased T helper (Th) 1 like immune profile, defined by high secretion of interferon (IFN) -γ. At the time of clinical onset of T1D, the Th1 dominance was diminished. We further demonstrate that children with newly diagnosed T1D had a suppressed Th1 like profile, detected by chemokine and chemokine receptor profile. This was accompanied by an induced population of CCR7+ and CD45RA+ naïve, CD8+cytotoxic T (Tc) cells and a reduced CD45RO+ memory Tc cell pool. It has previously been shown that oral Nicotinamide had no clinical effect in prevention of T1D. However, we found that the treatment was associated with a decreased secretion of IFN-γ. We have previously shown that subcutaneous injections with GAD-alum in T1D children induced a better preservation of endogenous insulin secretion compared with placebo. Here, we demonstrate that the treatment induced an early antigen-specific Th2 and regulatory immune profile. After a few months, and still after more than two years, the recall response to GAD65 was characterised by a broader range of cytokines. GAD-alum treatment also induced a GAD65-specific CD4+CD25highFOXP3+ cell population and reduced the levels of CD4+CD25+ cells. In conclusion, a Th1 like immune profile in pre-diabetic individuals indicates an imbalance of the immune system. At time of clinical onset, and in the period afterwards, reduction of the Th1 associated immune response could be an effect of a suppressed destructive process, selective recruitment of effector T cells to the pancreas or a defective immune regulation. The protective effect of GAD-alum in T1D children seems to be mediated by an early skewing of GAD65-induced responses towards a Th2 phenotype. Further, induction of GAD65-specific T cells with regulatory characteristics might be able to suppress autoreactive responses and inflammation in the pancreas.
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| 9. |
- Ludvigsson, Johnny, 1943-, et al.
(författare)
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GAD treatment and insulin secretion in recent-onset type 1 diabetes
- 2008
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Ingår i: New England Journal of Medicine. - Boston, Mass : Massachusetts medical society. - 0028-4793 .- 1533-4406. ; 359:18, s. 1909-1920
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Tidskriftsartikel (refereegranskat)abstract
- Background The 65-kD isoform of glutamic acid decarboxylase (GAD) is a major autoantigen in patients with type 1 diabetes mellitus. This trial assessed the ability of alum-formulated GAD (GAD-alum) to reverse recent-onset type 1 diabetes in patients 10 to 18 years of age. Methods We randomly assigned 70 patients with type 1 diabetes who had fasting C-peptide levels above 0.1 nmol per liter (0.3 ng per milliliter) and GAD autoantibodies, recruited within 18 months after receiving the diagnosis of diabetes, to receive subcutaneous injections of 20 μg of GAD-alum (35 patients) or placebo (alum alone, 35 patients) on study days 1 and 30. At day 1 and months 3, 9, 15, 21, and 30, patients underwent a mixed-meal tolerance test to stimulate residual insulin secretion (measured as the C-peptide level). The effect of GAD-alum on the immune system was also studied. Results Insulin secretion gradually decreased in both study groups. The study treatment had no significant effect on change in fasting C-peptide level after 15 months (the primary end point). Fasting C-peptide levels declined from baseline levels significantly less over 30 months in the GAD-alum group than in the placebo group (−0.21 vs. −0.27 nmol per liter [−0.62 vs. −0.81 ng per milliliter], P = 0.045), as did stimulated secretion measured as the area under the curve (−0.72 vs. −1.02 nmol per liter per 2 hours [−2.20 vs. −3.08 ng per milliliter per 2 hours], P = 0.04). No protective effect was seen in patients treated 6 months or more after receiving the diagnosis. Adverse events appeared to be mild and similar in frequency between the two groups. The GAD-alum treatment induced a GAD-specific immune response. Conclusions GAD-alum may contribute to the preservation of residual insulin secretion in patients with recent-onset type 1 diabetes, although it did not change the insulin requirement. (ClinicalTrials.gov number, NCT00435981.)
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| 10. |
- Axelsson, Stina, et al.
(författare)
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Decreased GAD(65) -specific Th1/Tc1 phenotype in children with Type 1 diabetes treated with GAD-alum.
- 2012
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Ingår i: Diabetic Medicine. - : Wiley-Blackwell. - 0742-3071 .- 1464-5491. ; 29:10, s. 1272-1278
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Tidskriftsartikel (refereegranskat)abstract
- Aim The balance between T helper cell subsets is an important regulator of the immune system and is often examined after immune therapies. We aimed to study the immunomodulatory effect of glutamic acid decarboxylase (GAD) 65 formulated with aluminium hydroxide (GAD-alum) in children with Type 1 diabetes, focusing on chemokines and their receptors. Methods Blood samples were collected from 70 children with Type 1 diabetes included in a phase II clinical trial with GAD-alum. Expression of CC chemokine receptor 5 (CCR5) and CCR4 was analysed on CD4+ and CD8+ lymphocytes after in vitro stimulation with GAD(65) using flow cytometry, and secretion of the chemokines CCL2, CCL3 and CCL4 was detected in peripheral blood mononuclear cell supernatants with Luminex. Results Expression of Th1-associated CCR5 was down-regulated following antigen challenge, together with an increased CCR4/CCR5 ratio and CCL2 secretion in GAD-alum-treated patients, but not in the placebo group. Conclusion Our results suggest that GAD-alum treatment has induced a favourable immune modulation associated with decreased Th1/Tc1 phenotypes upon antigen re-challenge, which may be of importance for regulating GAD(65) immunity. © 2012 The Authors. Diabetic Medicine © 2012 Diabetes UK.
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