| 1. |
- Axelsson, Stina, 1981-
(författare)
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GAD65 An Immunomodulator in Type 1 Diabetes
- 2012
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Type 1 diabetes (T1D) is caused by a deficiency of insulin as a result of an autoimmune destruction of the pancreatic ² -cells. A possibility to preserve remaining ² -cells in children with newly diagnosed T1D is of great importance since sustained ² -cell function is recognized to result in reduced end-organ complications. Glutamic acid decarboxylase 65 (GAD65) is one of the major antigens targeted by self-reactive T cells in T1D, and immunomodulation with GAD65 formulated in aluminum (GAD-alum) has been considered both in prevention and treatment of T1D. Results from a Phase II trial have shown clinical effect of subcutaneous injections with GAD-alum, this was unfortunately not fully confirmed in the following larger Phase III trial which therefore was closed after 15 months. The general aim of this thesis was to study the immunomodulatory effect of GAD-alum-treatment in children with T1D participating in the Phase II and Phase III trials. We hypothesized that treatment with GAD-alum contributes to the preservation of residual insulin secretion through deviation of the GAD65-specific immune response from a destructive to a protective process, accompanied by a shift from T helper (Th) 1 towards a predominant Th2 profile. In the Phase II trial, GAD-alum-treated patients responded with an early GAD65-specific Th2 skewed cytokine secretion, with highest IL-5 and IL-13 secretion in clinical responders. Also, the CCR4/CCR5 ratio indicating balance between Th2/Tc2 and Th1/Tc1 responses, increased in treated patients. The recall response to GAD65 was characterized by a wide range of cytokines, but the relative contribution of each cytokine suggests a shift towards a more pronounced Th2-associated profile over time. Induction of a CD4+ cell subset upon GAD65-stimulation 4 years after treatment, suggesting clonal expansion of the memory T-cell compartment upon antigen re-challenge, was seen in parallel to a persistent GAD65-specific cytokine response. Finally, even if the phase III trial failed to reach the primary endpoint at 15 months, a subgroup analysis showed that the treatment had an effect on preservation of residual insulin secretion, but the effect was not seen until after 30 months. Taken together, these results suggest that GAD-alum treatment might exert its effect through induction of an early Th2 skewed immune response which tends to deviate away from a destructive Th1/Tc1 response upon GAD65 re-challenge, and generation of GAD65-specific memory T cells that produce cytokines and exert effector responses which may be important for regulating GAD65 immunity. Continued research to better understand how immunomodulation with autoantigen modifies T-cell responses and also which patients are suitable for treatment, is crucial for optimizing future intervention trials using ² -cell antigens.
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| 2. |
- Bronge, Mattias, et al.
(författare)
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Identification of four novel T cell autoantigens and personal autoreactive profiles in multiple sclerosis
- 2022
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Ingår i: Science Advances. - : American Association for the Advancement of Science (AAAS). - 2375-2548. ; 8:17
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Tidskriftsartikel (refereegranskat)abstract
- Multiple sclerosis (MS) is an inflammatory disease of the central nervous system (CNS), in which pathological T cells, likely autoimmune, play a key role. Despite its central importance, the autoantigen repertoire remains largely uncharacterized. Using a novel in vitro antigen delivery method combined with the Human Protein Atlas library, we screened for T cell autoreactivity against 63 CNS-expressed proteins. We identified four previously unreported autoantigens in MS: fatty acid-binding protein 7, prokineticin-2, reticulon-3, and synaptosomal-associated protein 91, which were verified to induce interferon-gamma responses in MS in two cohorts. Autoreactive profiles were heterogeneous, and reactivity to several autoantigens was MS-selective. Autoreactive T cells were predominantly CD4(+) and human leukocyte antigen-DR restricted. Mouse immunization induced antigen-specific responses and CNS leukocyte infiltration. This represents one of the largest systematic efforts to date in the search for MS autoantigens, demonstrates the heterogeneity of autoreactive profiles, and highlights promising targets for future diagnostic tools and immunomodulatory therapies in MS.
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| 3. |
- Högelin, Klara Asplund, et al.
(författare)
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Development of humoral and cellular immunological memory against SARS-CoV-2 despite B cell depleting treatment in multiple sclerosis
- 2021
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Ingår i: iScience. - : Elsevier BV. - 2589-0042. ; 24:9
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Tidskriftsartikel (refereegranskat)abstract
- B cell depleting therapies (BCDTs) are widely used as immunomodulating agents for autoimmune diseases such as multiple sclerosis. Their possible impact on development of immunity to severe acute respiratory syndrome virus-2 (SARS-CoV-2) has raised concerns with the coronavirus disease 2019 (COVID-19) pandemic. We here evaluated the frequency of COVID-19-like symptoms and determined immunological responses in participants of an observational trial comprising several multiple sclerosis disease modulatory drugs (COMBAT-MS; NCT03193866) and in eleven patients after vaccination, with a focus on BCDT. Almost all seropositive and 17.9% of seronegative patients on BCDT, enriched for a history of COVID-19-like symptoms, developed anti-SARS-CoV-2 T cell memory, and T cells displayed functional similarity to controls producing IFN-gamma and TNF. Following vaccination, vaccine-specific humoral memory was impaired, while all patients developed a specific T cell response. These results indicate that BCDTs do not abrogate SARS-CoV-2 cellular memory and provide a possible explanation as to why the majority of patients on BCDTs recover from COVID-19.
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| 4. |
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| 5. |
- Lundstrom, Susanna L., et al.
(författare)
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Allergic Asthmatics Show Divergent Lipid Mediator Profiles from Healthy Controls Both at Baseline and following Birch Pollen Provocation
- 2012
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 7:3
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Tidskriftsartikel (refereegranskat)abstract
- Background: Asthma is a respiratory tract disorder characterized by airway hyper-reactivity and chronic inflammation. Allergic asthma is associated with the production of allergen-specific IgE and expansion of allergen-specific T-cell populations. Progression of allergic inflammation is driven by T-helper type 2 (Th2) mediators and is associated with alterations in the levels of lipid mediators. Objectives: Responses of the respiratory system to birch allergen provocation in allergic asthmatics were investigated. Eicosanoids and other oxylipins were quantified in the bronchoalveolar lumen to provide a measure of shifts in lipid mediators associated with allergen challenge in allergic asthmatics. Methods: Eighty-seven lipid mediators representing the cyclooxygenase (COX), lipoxygenase (LOX) and cytochrome P450 (CYP) metabolic pathways were screened via LC-MS/MS following off-line extraction of bronchoalveolar lavage fluid (BALF). Multivariate statistics using OPLS were employed to interrogate acquired oxylipin data in combination with immunological markers. Results: Thirty-two oxylipins were quantified, with baseline asthmatics possessing a different oxylipin profile relative to healthy individuals that became more distinct following allergen provocation. The most prominent differences included 15-LOX-derived omega-3 and omega-6 oxylipins. Shared-and-Unique-Structures (SUS)-plot modeling showed a correlation (R-2 = 0.7) between OPLS models for baseline asthmatics ((RY)-Y-2[cum] = 0.87, Q(2)[cum] = 0.51) and allergen-provoked asthmatics ((RY)-Y-2[cum] = 0.95, Q(2)[cum] = 0.73), with the majority of quantified lipid mediators and cytokines contributing equally to both groups. Unique structures for allergen provocation included leukotrienes (LTB4 and 6-trans-LTB4), CYP-derivatives of linoleic acid (epoxides/diols), and IL-10. Conclusions: Differences in asthmatic relative to healthy profiles suggest a role for 15-LOX products of both omega-6 and omega-3 origin in allergic inflammation. Prominent differences at baseline levels indicate that non-symptomatic asthmatics are subject to an underlying inflammatory condition not observed with other traditional mediators. Results suggest that oxylipin profiling may provide a sensitive means of characterizing low-level inflammation and that even individuals with mild disease display distinct phenotypic profiles, which may have clinical ramifications for disease.
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| 6. |
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| 7. |
- Thomas, Olivia G., et al.
(författare)
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Cross-reactive EBNA1 immunity targets alpha-crystallin B and is associated with multiple sclerosis
- 2023
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Ingår i: Science Advances. - : American Association for the Advancement of Science (AAAS). - 2375-2548. ; 9:20
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Tidskriftsartikel (refereegranskat)abstract
- Multiple sclerosis (MS) is an inflammatory disease of the central nervous system, for which and Epstein-Barr virus (EBV) infection is a likely prerequisite. Due to the homology between Epstein-Barr nuclear antigen 1 (EBNA1) and alpha-crystallin B (CRYAB), we examined antibody reactivity to EBNA1 and CRYAB peptide libraries in 713 persons with MS (pwMS) and 722 matched controls (Con). Antibody response to CRYAB amino acids 7 to 16 was associated with MS (OR = 2.0), and combination of high EBNA1 responses with CRYAB positivity markedly in-creased disease risk (OR = 9.0). Blocking experiments revealed antibody cross-reactivity between the homolo-gous EBNA1 and CRYAB epitopes. Evidence for T cell cross-reactivity was obtained in mice between EBNA1 and CRYAB, and increased CRYAB and EBNA1 CD4+ T cell responses were detected in natalizumab-treated pwMS. This study provides evidence for antibody cross-reactivity between EBNA1 and CRYAB and points to a similar cross-reactivity in T cells, further demonstrating the role of EBV adaptive immune responses in MS development.
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| 8. |
- Velickovic, Tanja Cirkovic, et al.
(författare)
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Low levels of endotoxin enhance allergen-stimulated proliferation and reduce the threshold for activation in human peripheral blood cells
- 2008
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Ingår i: International Archives of Allergy and Immunology. - : S. Karger AG. - 1018-2438 .- 1423-0097. ; 146:1, s. 1-10
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Tidskriftsartikel (refereegranskat)abstract
- Background: Endotoxins, comprised of bacterial cell wall lipopolysaccharides (LPS), have been reported to have both protective and exacerbating effects on the development and maintenance of allergic disease in humans and on markers of allergic inflammation in animal models of allergy. In this study, we investigated the effect of low concentrations of LPS on human peripheral blood mononuclear cells (PBMC) stimulated with the major cat allergen Fel d 1. Methods: Extensive purification of recombinant (r) Fel d 1 yielded essentially endotoxin-free rFel d 1 (0.2 ng LPS/mg protein). PBMCs prepared from 15 subjects having IgE to cat (>0.7 kU(A)/l) and 8 subjects IgE negative to cat were stimulated with 2, 10 or 25 mu g/ml of rFel d 1 in the presence or absence of 50 pg/ml LPS. Proliferation was measured after 7 days of culture and supernatants were analyzed for IFN gamma, IL-5 and IL-10. Results: LPS (50 pg/ml) increased rFel d 1-stimulated proliferation of PBMCs both from subjects IgE-positive and subjects negative to cat allergens. PBMCs from 13 of the subjects did not proliferate in response to stimulation with 2 and 10 mu g/ml rFel d 1 alone but did so in the presence of LPS. Moreover, LPS increased the levels of rFel d 1-stimulated IFN gamma in cultures from cat-negative subjects, IL-5 from cat-positive subjects and IL-10 from both groups. Conclusion: Very low doses of LPS enhance proliferation and decrease the apparent threshold level for cell activation, prompting careful evaluation of allergen stimulated T cell activation in vitro. Copyright (C) 2007 S. Karger AG, Basel.
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| 9. |
- Victor, Susanne, et al.
(författare)
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Measurement of Horse Allergens Equ c 1 and Equ c 2 : A Comparison among Breeds
- 2022
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Ingår i: International Archives of Allergy and Immunology. - : S. Karger. - 1018-2438 .- 1423-0097. ; 183:11, s. 1166-1177
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Horse allergens are less studied than allergens from other furry animals and these allergens must be evaluated to understand the complexity of allergy to horses. The aims of this study were to develop assays for the horse allergens Equ c 1 and Equ c 2 in dander and saliva and to determine their levels in ten horse breeds. The study also included a comparison of these findings with previous results on the levels of Equ c 4 performed on the same study population. Method: The study population included 170 horses from 10 horse breeds including American Curly and Russian Bashkir horse, which have been suggested to be hypoallergenic. Competitive ELISA assays were developed, with polyclonal antibodies as capture antibodies, for the detection of Equ c 1 and Equ c 2 in dander and saliva samples. Results: The horse allergens Equ c 1 and Equ c 2 were found in all dander and saliva samples from the ten horse breeds. The GM level (ng/mu g protein) of Equ c 1 in dander was 470 (range 129-2,569) and in saliva samples, 40 (range 6-160). The GM level of Equ c 2 in dander was 138 (range 18-1,650) and in saliva samples, 0.8 (range 0.03-17). In dander, there were no significant differences in Equ c 1 and Equ c 2 GM levels between stallions, mares, and geldings. Conclusion: Our results show high intra- and inter-breed variability. Neither the American Curly horse nor the Russian Bashkir horse, earlier categorized as hypoallergenic breeds, was associated with lower allergen levels of Equ c 1, Equ c 2, or Equ c 4 than the other horse breeds investigated.
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| 10. |
- Österlund, Camilla, 1978-, et al.
(författare)
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Non-proteolytic aeroallergens from mites, cat and dog exert adjuvant-like activation of bronchial epithelial cells
- 2011
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Ingår i: International Archives of Allergy and Immunology. - : S. Karger AG. - 1018-2438 .- 1423-0097. ; 155:2, s. 111-118
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Tidskriftsartikel (refereegranskat)abstract
- Background: Exposure to seasonal or indoor allergens may cause sensitisation and development of allergic airway diseases. We have previously demonstrated that the non-proteolytic major house dust mite (HDM) allergen Der p 2 stimulates pro-inflammatory responses in bronchial epithelial cells. We aimed to determine if other clinically relevant non-proteolytic aeroallergens originating from HDMs, storage mites, cat, dog, birch and timothy also activate respiratory epithelial cells. Methods: Cultures of human bronchial epithelial cell line BEAS-2B, normal human bronchial epithelial cells and alveolar epithelial cell line A549 were exposed to recombinant (r)Der p 2, natural (n)Der f 2, rEur m 2, rLep d 2, rFel d 1, nFel d 1, rCan f 2, rBet v 1 or rPhl p 5a. A panel of secreted mediators and expression of cell adhesion receptors involved in recruitment, survival and adhesion of inflammatory cells in asthmatic airways was assessed. Results: The mite allergens rDer p 2, nDer f 2, rEur m 2 and rLep d 2 as well as the cat and dog allergens rFel d 1, nFel d 1 and rCan f 2 induced granulocyte colony-stimulating factor, granulocyte-macrophage colony-stimulating factor, interleukin (IL)-6, IL-8, monocyte-chemotactic protein-1 and macrophage inflammatory protein-3α secretion from bronchial epithelial cells as well as surface expression of intracellular adhesion molecule-1. The pollen allergens rBet v 1 and rPhl p 5a from birch and timothy did not activate the cells. None of the studied allergens affected the alveolar epithelial cells. Conclusion: These results show that both mite and structurally unrelated cat and dog allergens can activate respiratory epithelial cells by adjuvant-like protease-independent mechanisms.
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