| 1. |
- Gudmundsdottir, J. A., et al.
(författare)
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Normal neonatal TREC and KREC levels in early onset juvenile idiopathic arthritis
- 2023
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Ingår i: Clinical Immunology. - : Elsevier BV. - 1521-6616 .- 1521-7035. ; 249
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Dysregulated central tolerance predisposes to autoimmune diseases. Reduced thymic output as well as compromised central B cell tolerance checkpoints have been proposed in the pathogenesis of juvenile idiopathic arthritis (JIA). The aim of this study was to investigate neonatal levels of T-cell receptor excision circles (TRECs) and kappa-deleting element excision circles (KRECs), as markers of T-and B-cell output at birth, in patients with early onset JIA.Methods: TRECs and KRECs were quantitated by multiplex qPCR from dried blood spots (DBS), collected 2-5 days after birth, in 156 children with early onset JIA and in 312 matched controls.Results: When analysed from neonatal dried blood spots, the median TREC level was 78 (IQR 55-113) in JIA cases and 88 (IQR 57-117) copies/well in controls. The median KREC level was 51 (IQR 35-69) and 53 (IQR 35-74) copies/well, in JIA cases and controls, respectively. Stratification by sex and age at disease onset did not reveal any difference in the levels of TRECs and KRECs.Conclusion: T-and B-cell output at birth, as measured by TREC and KREC levels in neonatal dried blood spots, does not differ in children with early onset JIA compared to controls.
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| 2. |
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| 3. |
- Lingman Framme, Jenny, 1977, et al.
(författare)
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Long-Term Follow-Up of Newborns with 22q11 Deletion Syndrome and Low TRECs
- 2022
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Ingår i: Journal of Clinical Immunology. - : Springer. - 0271-9142 .- 1573-2592. ; 42, s. 618-633
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Tidskriftsartikel (refereegranskat)abstract
- Background: Population-based neonatal screening using T-cell receptor excision circles (TRECs) identifies infants with profound T lymphopenia, as seen in cases of severe combined immunodeficiency, and in a subgroup of infants with 22q11 deletion syndrome (22q11DS).Purpose: To investigate the long-term prognostic value of low levels of TRECs in newborns with 22q11DS.Methods: Subjects with 22q11DS and low TRECs at birth (22q11Low, N=10), matched subjects with 22q11DS and normal TRECs (22q11Normal, N=10), and matched healthy controls (HC, N=10) were identified. At follow-up (median age 16 years), clinical and immunological characterizations, covering lymphocyte subsets, immunoglobulins, TRECs, T-cell receptor repertoires, and relative telomere length (RTL) measurements were performed.Results: At follow-up, the 22q11Low group had lower numbers of naïve T-helper cells, naïve T-regulatory cells, naïve cytotoxic T cells, and persistently lower TRECs compared to healthy controls. Receptor repertoires showed skewed V-gene usage for naïve T-helper cells, whereas for naïve cytotoxic T cells, shorter RTL and a trend towards higher clonality were found. Multivariate discriminant analysis revealed a clear distinction between the three groups and a skewing towards Th17 differentiation of T-helper cells, particularly in the 22q11Low individuals. Perturbations of B-cell subsets were found in both the 22q11Low and 22q11Normal group compared to the HC group, with larger proportions of naïve B cells and lower levels of memory B cells, including switched memory B cells.Conclusions: This long-term follow-up study shows that 22q11Low individuals have persistent immunologic aberrations and increased risk for immune dysregulation, indicating the necessity of lifelong monitoring.Clinical Implications: This study elucidates the natural history of childhood immune function in newborns with 22q11DS and low TRECs, which may facilitate the development of programs for long-term monitoring and therapeutic choices.
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| 4. |
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| 5. |
- Wing, Kajsa, 1977, et al.
(författare)
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CD4 T cell activation by myelin oligodendrocyte glycoprotein is suppressed by adult but not cord blood CD25+ T cells.
- 2003
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Ingår i: European journal of immunology. - : Wiley. - 0014-2980 .- 1521-4141. ; 33:3, s. 579-87
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Tidskriftsartikel (refereegranskat)abstract
- Regulatory T cells expressing CD25 have been shown to protect rodents from organ-specific autoimmune diseases. Similar CD25+ cells with a memory phenotype exerting suppressive function after polyclonal or allogeneic stimulation are also present in adult human blood. We demonstrate that adult human CD25+ cells regulate the response to myelin oligodendrocyte glycoprotein (MOG), as depletion of CD25(+) cells increases responses of PBMC and the addition of purified CD25+ cells suppresses MOG-specific proliferation and IFN-gamma production of CD4(+)CD25(-) T cells. In contrast, cord blood CD25+ cells do not inhibit responses to self antigens, and only a small subpopulation of cord CD25+ cells expresses the typical phenotype of adult regulatory T cells (CD45RA(-) and GITR(+)) enabling suppression of polyclonal responses. We conclude that activation of self-reactive T cells in normal healthy individuals is prevented by the presence of self-antigen-specific CD25+ regulatory T cells and that the majority of these cells mature after birth.
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| 6. |
- Carlströmer Berthén, Nellie, et al.
(författare)
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The AxBioTick Study: Borrelia Species and Tick-Borne Encephalitis Virus in Ticks, and Clinical Responses in Tick-Bitten Individuals on the Aland Islands, Finland
- 2023
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Ingår i: Microorganisms. - : MDPI. - 2076-2607. ; 11:5
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Tidskriftsartikel (refereegranskat)abstract
- The AxBioTick Study: Borrelia Species and Tick-Borne Encephalitis Virus in Ticks, and Clinical Responses in Tick-Bitten Individuals on the Aland Islands, Finlandby Nellie Carlströmer Berthén 1,2,*,† , Eszter Tompa 3,† , Susanne Olausson 1,2, Clara Nyberg 1, Dag Nyman 1,2, Malin Ringbom 1,4, Linda Perander 1,4, Joel Svärd 3, Per-Eric Lindgren 3,5, Pia Forsberg 3, Peter Wilhelmsson 3,5,‡, Johanna Sjöwall 3,6,‡ and Marika Nordberg 1,4,‡ 1Borrelia Research Group of the Aland Islands, 22100 Mariehamn, The Aland Islands, Finland2Bimelix AB, 22100 Mariehamn, The Aland Islands, Finland3Department of Biomedical and Clinical Sciences, Division of Inflammation and Infection, Linkoping University, 581 83 Linkoping, Sweden4The Aland Islands Healthcare Services, 22100 Mariehamn, The Aland Islands, Finland5Clinical Microbiology, Laboratory Medicine, County Hospital Ryhov, 551 85 Jonkoping, Sweden6Department of Infectious Diseases, Vrinnevi Hospital, 603 79 Norrkoping, Sweden*Author to whom correspondence should be addressed.†These authors contributed equally to the study.‡These authors contributed equally to the study.Microorganisms 2023, 11(5), 1100; https://doi.org/10.3390/microorganisms11051100Received: 30 March 2023 / Revised: 17 April 2023 / Accepted: 19 April 2023 / Published: 22 April 2023(This article belongs to the Special Issue Research on Ticks and Tick-Borne Pathogens)Download Browse Figures Versions NotesArticle Views585 AbstractThe AxBioTick study was initiated to investigate the prevalence of ticks and tick-borne pathogens and their impact on antibody and clinical responses in tick-bitten individuals on the Aland Islands. This geographical area is hyperendemic for both Lyme borreliosis (LB) and Tick-borne encephalitis (TBE). Blood samples and ticks were collected from 100 tick-bitten volunteers. A total of 425 ticks was collected, all determined to Ixodes ricinus using molecular tools. Of them 20% contained Borrelia species, of which B. garinii and B. afzelii were most common. None contained the TBE virus (TBEV). Blood samples were drawn in conjunction with the tick bite, and eight weeks later. Sera were analyzed for Borrelia- and TBEV-specific antibodies using an ELISA and a semiquantitative antibody assay. In total 14% seroconverted in Borrelia C6IgG1, 3% in TBEV IgG, and 2% in TBEV IgM. Five participants developed clinical manifestations of LB. The high seroprevalence of both Borrelia (57%) and TBEV (52%) antibodies are likely attributed to the endemic status of the corresponding infections as well as the TBE vaccination program. Despite the similar prevalence of Borrelia spp. detected in ticks in other parts of Europe, the infection rate in this population is high. The AxBioTick study is continuing to investigate more participants and ticks for co-infections, and to characterize the dermal immune response following a tick bite.
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| 7. |
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| 8. |
- Lindgren, Susanne, 1977
(författare)
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On the regulation of immune responses to dietary and self antigens
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Regulatory mechanisms are necessary to avoid the misdirected aggressive immune responses responsible for the pathology seen in autoimmunity and allergy. Thymic-derived CD4+CD25+ regulatory T cells are indispensible for this regulation. We investigated if CD4+CD25+ Treg prevents auto-reactive responses in adult peripheral blood and cord blood. Mononuclear cells, as well as CD4+ T cells isolated from peripheral blood of adults or from cord blood, were stimulated with self-antigens and recall antigens in the absence or presence of CD25+ cells. We demonstrate that adult human CD25+ cells regulate the response to myelin oligodendrocyte glycoprotein (MOG), while cord blood CD25+ cells are not equally efficient in the inhibition of responses to self-antigens. We conclude that activation of self-reactive T cells in normal healthy individuals is prevented by the presence of self-antigen-specific CD25+ regulatory T cells and that the majority of these cells mature after birth. T cells with regulatory properties can also be induced in the periphery, for example in response to a fed antigen. The physiological requirements and localization of the tolerance induction are largely unknown. We studied the antigen-specific activation and induction of regulatory T cells from naïve CD4+ T cells in different lymphoid compartments following oral administration of a protein antigen. A significantly higher proportion of antigen-specific CD4+ T cells developed into the putative regulatory phenotype in the liver-draining celiac lymph node (CLN), compared to other sites. This suggests that induction of regulatory T cells in the CLN may be relevant for the generation of tolerance to dietary antigens. Oral tolerance is impaired in germfree animals, which indicates a role of the enteric flora. Using a mouse model of allergic airway inflammation, we investigated how a natural adjuvant from the commensal microflora, Staphylococcus aureus enterotoxin A (SEA), aids in the tolerogenic processing of antigens. We found that recipients of serum from SEA-treated and ovalbumin-fed donors were better protected against allergic airway inflammation with diminished influx of eosinophils into the lungs and reduced antigen-induced production of interleukin-5 and interleukin-13 compared to controls. This was associated with increased density of CD8α+ intraepithelial lymphocytes in gut-sections from SEA treated donors. Our results suggest that SEA promotes oral tolerance by facilitating tolerogenic processing of dietary antigens, possibly via activation of intraepithelial lymphocytes acting on the absorptive intestinal epithelium. Intestinal epithelial cells have the capacity to sample and package environmental antigens into exosomes, which are found in the serum-fraction that mediates antigen-specific tolerance when transferred to naïve recipients. Exosomes isolated from the murine small intestinal epithelial cell line IEC4.1 were characterized by flow cytometry, electron microscopy and their immunomodulatory capacity was explored in a mouse model of ovalbumin-induced allergic airway inflammation. The exosomes were found to carry MHC class I, MHC class II, CD9 and MFGE-8. When antigen-pulsed exosomes from IEC4.1 cells stimulated with low level of IFN-γ were given to naïve mice they were able to partly prevent the allergic sensitisation.
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| 9. |
- Lundberg, Vanja, et al.
(författare)
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Thymic exosomes promote the final maturation of thymocytes
- 2016
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- Extensive knowledge has been gained the last years concerning mechanisms underlying the selection of single positive thymocytes in the thymic medulla. Less is known regarding other important processes in the thymic medulla such as the regulation of late stage thymocyte maturation. We have previously reported that exosomes are abundant in the thymus with a phenotype that indicates an epithelial cell origin and immunoregulatory properties. In this study we use an in vitro system to investigate the effects of thymic exosomes on the maturation of single positive thymocytes as well as effects on nTreg formation. We show that thymic exosomes promote the maturation of single positive CD4(+)CD25(-) cells into mature thymocytes with S1P(1)(+)Qa2(+) and CCR7(+)Qa2(+) phenotypes. Furthermore, we show that thymic exosomes reduce the formation of CD4(+)CD25(+)FoxP3(+) thymocytes and that these exosome effects are independent of dendritic cell co-stimulation but require intact exosomal RNA content and surface proteins. An efficient direct uptake of exosomes by both thymocytes and thymic DC's is also demonstrated. In conclusion, this study demonstrates that exosomes may represent a new route of communication within the thymus.
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| 10. |
- Skogberg, Gabriel, et al.
(författare)
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Altered expression of autoimmune regulator in infant down syndrome thymus, a possible contributor to an autoimmune phenotype.
- 2014
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Ingår i: Journal of Immunology. - : The American Association of Immunologists. - 0022-1767 .- 1550-6606. ; 193:5, s. 2187-95
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Tidskriftsartikel (refereegranskat)abstract
- Down syndrome (DS), caused by trisomy of chromosome 21, is associated with immunological dysfunctions such as increased frequency of infections and autoimmune diseases. Patients with DS share clinical features, such as autoimmune manifestations and specific autoantibodies, with patients affected by autoimmune polyendocrine syndrome type 1. Autoimmune polyendocrine syndrome type 1 is caused by mutations in the autoimmune regulator (AIRE) gene, located on chromosome 21, which regulates the expression of tissue-restricted Ags (TRAs) in thymic epithelial cells. We investigated the expression of AIRE and TRAs in DS and control thymic tissue using quantitative PCR. AIRE mRNA levels were elevated in thymic tissue from DS patients, and trends toward increased expression of the AIRE-controlled genes INSULIN and CHRNA1 were found. Immunohistochemical stainings showed altered cell composition and architecture of the thymic medulla in DS individuals with increased frequencies of AIRE-positive medullary epithelial cells and CD11c-positive dendritic cells as well as enlarged Hassall's corpuscles. In addition, we evaluated the proteomic profile of thymic exosomes in DS individuals and controls. DS exosomes carried a broader protein pool and also a larger pool of unique TRAs compared with control exosomes. In conclusion, the increased AIRE gene dose in DS could contribute to an autoimmune phenotype through multiple AIRE-mediated effects on homeostasis and function of thymic epithelial cells that affect thymic selection processes.
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| 11. |
- Skogberg, Gabriel, et al.
(författare)
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Human thymic epithelial primary cells produce exosomes carrying tissue-restricted antigens.
- 2015
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Ingår i: Immunology and cell biology. - : Wiley. - 1440-1711 .- 0818-9641. ; 93, s. 727-73
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Tidskriftsartikel (refereegranskat)abstract
- Exosomes are nano-sized vesicles released by cells into the extracellular space and have been shown to be present in thymic tissue both in mice and in humans. The source of thymic exosomes is however still an enigma and hence it is not known whether thymic epithelial cells (TECs) are able to produce exosomes. In this work, we have cultured human TECs and isolated exosomes. These exosomes carry tissue-restricted antigens (TRAs), for example, myelin basic protein and desmoglein 3. The presence of TRAs indicates a possible role for thymic epithelium-derived exosomes in the selection process of thymocytes. The key contribution of these exosomes could be to disseminate self-antigens from the thymic epithelia, thus making them more accessible to the pool of maturing thymocytes. This would increase the coverage of TRAs within the thymus, and facilitate the process of positive and negative selection.Immunology and Cell Biology advance online publication, 17 March 2015; doi:10.1038/icb.2015.33.
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| 12. |
- Wilhelmson, Anna S K, et al.
(författare)
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Androgen Receptors in Epithelial Cells Regulate Thymopoiesis and Recent Thymic Emigrants in Male Mice
- 2020
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Ingår i: Frontiers in Immunology. - : Frontiers Media SA. - 1664-3224. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- Androgens have profound effects on T cell homeostasis, including regulation of thymic T lymphopoiesis (thymopoiesis) and production of recent thymic emigrants (RTEs), i. e., immature T cells that derive from the thymus and continue their maturation to mature naive T cells in secondary lymphoid organs. Here we investigated the androgen target cell for effects on thymopoiesis and RTEs in spleen and lymph nodes. Male mice with a general androgen receptor knockout (G-ARKO), T cell-specific (T-ARKO), or epithelial cell-specific (E-ARKO) knockout were examined. G-ARKO mice showed increased thymus weight and increased numbers of thymic T cell progenitors. These effects were not T cell-intrinsic, since T-ARKO mice displayed unaltered thymus weight and thymopoiesis. In line with a role for thymic epithelial cells (TECs), E-ARKO mice showed increased thymus weight and numbers of thymic T cell progenitors. Further, E-ARKO mice had more CD4(+)and CD8(+)T cells in spleen and an increased frequency of RTEs among T cells in spleen and lymph nodes. Depletion of the androgen receptor in epithelial cells was also associated with a small shift in the relative number of cortical (reduced) and medullary (increased) TECs and increased CCL25 staining in the thymic medulla, similar to previous observations in castrated mice. In conclusion, we demonstrate that the thymic epithelium is a target compartment for androgen-mediated regulation of thymopoiesis and consequently the generation of RTEs.
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| 13. |
- Wilhelmson, Anna S K, et al.
(författare)
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Testosterone Protects Against Atherosclerosis in Male Mice by Targeting Thymic Epithelial Cells.
- 2018
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Ingår i: Arteriosclerosis, thrombosis, and vascular biology. - 1524-4636. ; 38:7, s. 1519-1527
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Tidskriftsartikel (refereegranskat)abstract
- Androgen deprivation therapy has been associated with increased cardiovascular risk in men. Experimental studies support that testosterone protects against atherosclerosis, but the target cell remains unclear. T cells are important modulators of atherosclerosis, and deficiency of testosterone or its receptor, the AR (androgen receptor), induces a prominent increase in thymus size. Here, we tested the hypothesis that atherosclerosis induced by testosterone deficiency in male mice is T-cell dependent. Further, given the important role of the thymic epithelium for T-cell homeostasis and development, we hypothesized that depletion of the AR in thymic epithelial cells will result in increased atherosclerosis.Prepubertal castration of male atherosclerosis-prone apoE-/- mice increased atherosclerotic lesion area. Depletion of T cells using an anti-CD (cluster of differentiation) 3 antibody abolished castration-induced atherogenesis, demonstrating a role of T cells. Male mice with depletion of the AR specifically in epithelial cells (E-ARKO [epithelial cell-specific AR knockout] mice) showed increased thymus weight, comparable with that of castrated mice. E-ARKO mice on an apoE-/- background displayed significantly increased atherosclerosis and increased infiltration of T cells in the vascular adventitia, supporting a T-cell-driven mechanism. Consistent with a role of the thymus, E-ARKO apoE-/- males subjected to prepubertal thymectomy showed no atherosclerosis phenotype.We show that atherogenesis induced by testosterone/AR deficiency is thymus- and T-cell dependent in male mice and that the thymic epithelial cell is a likely target cell for the antiatherogenic actions of testosterone. These insights may pave the way for new therapeutic strategies for safer endocrine treatment of prostate cancer.
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