| 1. |
- Bjersing, Jan, 1966, et al.
(författare)
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Loss of ileal IgA+ plasma cells and of CD4+ lymphocytes in ileal Peyer's patches of vitamin A deficient rats.
- 2002
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Ingår i: Clinical and experimental immunology. - 0009-9104. ; 130:3, s. 404-8
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Tidskriftsartikel (refereegranskat)abstract
- Child mortality in diarrhoeal disease is increased significantly by vitamin A deficiency in poor countries. The pathological mechanisms are not known in detail. However, in this paper we report that vitamin A-deficient Wistar rats had much reduced IgA+ plasma cells in the ileal lamina propria (eightfold reduction from 470 cells/mm(2), P = 0.009), as well as a prominent reduction of CD4+ cells in the parafollicular regions of ileal Peyer's patches (reduction from 7200 to 105 cells/mm(2), P = 0.009). IL-2Ralpha-chain (CD25) positive lymphocytes in the ileal Peyer's patches were also reduced significantly in vitamin A deficiency (from 1400 to 300 cells/mm(2), P = 0.009). The density of CD8 cells tended to be increased relative to the control animals (from 5100 to 6000 cells/mm(2), not statistically significant). In conclusion, the marked decrease of lamina propria IgA+ plasma cells may be one cause of the high diarrhoeal mortality in vitamin A deficiency. This, in turn, appears to be related to reduced numbers of activated or regulatory CD4+ T cells in Peyer's patches.
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| 2. |
- Bratel, John, 1953, et al.
(författare)
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The frequency of different T-cell receptor V-families in oral lichen planus and lichenoid contact lesions: an immunohistochemical study.
- 1998
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Ingår i: Journal of oral pathology & medicine : official publication of the International Association of Oral Pathologists and the American Academy of Oral Pathology. - 0904-2512. ; 27:9, s. 415-9
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Tidskriftsartikel (refereegranskat)abstract
- Oral lichen planus (OLP) and lichenoid contact lesions (CL) are recognized as different pathological conditions of the oral mucosa. Cutaneous delayed-type hypersensitivity to mercury displayed by patients with CL but not by OLP patients supports the concept of different etiological mechanisms behind the two lesions. It is not possible to reveal this difference by histopathological assessments, and differences in clinical appearances are at present the only way to discriminate between the two conditions. It has recently been observed that T cells in OLP lesions express T-cell receptors (TCR) belonging to the Vbeta3 family in a higher frequency than expected from a random distribution, suggesting an involvement of superantigens as an etiologic factor behind this condition. In an effort to discriminate more clearly between OLP and CL, and to provide clues to the etiological mechanisms behind the two lesions, the TCR V-family distributions in the inflammatory infiltrates of OLP and CL were compared. Biopsies were taken from 10 patients with manifest OLP and 10 patients with CL. Frozen sections were incubated with antibodies against TCR Vbeta3, Valpha2 and Vbeta5a utilizing a standard immunoperoxidase technique. The frequency of Vbeta3.1 (clone 8F10) was calculated as 7%, and for Valpha2 less than 3%, and the results did not reveal any differences between OLP and CL regarding the frequencies of T-cell V-families. Thus, it was not possible to discriminate between OLP and CL by immunohistochemistry staining for different V families.
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| 3. |
- Dahlman-Höglund, Anna, 1964, et al.
(författare)
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Antibodies given orally in the neonatal period can affect the immune response for two generations: evidence for active maternal influence on the newborn's immune system.
- 1999
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Ingår i: Scandinavian journal of immunology. - 0300-9475. ; 50:6, s. 651-6
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Tidskriftsartikel (refereegranskat)abstract
- Two day old Wistar rats were tube fed with 1 or 10 micrograms of a mouse IgG1 monoclonal anti-idiotypic (a-Id) antibody that was directed against an anti-Escherichia coli-K13 capsular polysaccharide antibody. A control group was given 10 micrograms of an unrelated control antibody. Six weeks after the administration of antibodies, the rats were intestinally colonised with an ovalbumin (OVA)-producing E. coli O6K13 strain. At 8 weeks of age, the male rats (first generation) and the offsprings of the female rats (second generation), were parenterally immunised with OVA and dead wild type E. coli O6K13, and the immune response was followed. In the rats of the first generation, there were no major differences between the groups in the immune response to the bacterium. However, the offspring of the neonatally a-Id administered rats had a profoundly affected immune response to the idiotypically connected antigen K13, but also to other antigens on the bacteria. Thus, a-Id treatment in the first generation gave, in the second generation, a greatly enhanced serum antibody response to the spatially related antigens OVA and O6 LPS, as well as to the idiotypically connected antigen K13. Concurrently, the in vitro spleen cell proliferative response to both OVA and the wild type bacterium was lowered. Overall, greater effects were seen with the higher dose of a-Id. In conclusion, our results demonstrate that by giving monoclonal antibodies idiotypically connected to a single bacterial component to neonatal rats, one profoundly influence the immune response also to other-spatially related-bacterial antigens in their offsprings.
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| 4. |
- Dahlman-Höglund, Anna, 1964, et al.
(författare)
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Immune response against ovalbumin in rats colonized with an ovalbumin-producing Escherichia coli and the influence of feeding ovalbumin.
- 1994
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Ingår i: International archives of allergy and immunology. - 1018-2438. ; 105:4, s. 381-5
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Tidskriftsartikel (refereegranskat)abstract
- The influence of feeding ovalbumin (OA) on the development of IgE/IgG antibodies and delayed-type hypersensitivity (DTH) against OA was studied in rats colonized from birth with an Escherichia coli genetically manipulated to produce OA. At 21 days of age, colonized pups and pups with a normal intestinal flora were weaned onto either an OA-containing or a conventional diet without OA. At 2 months of age the colonized rats showed an increased DTH reaction to OA, but they did not have any anti-OA antibodies in serum. The rats were then immunized intracutaneously with OA in Freund's complete adjuvant. After immunization the colonized rats fed the conventional diet had a significantly higher DTH reaction to OA and significantly higher serum levels of IgE anti-OA antibodies than the uncolonized rats on the same diet. The colonized rats eating the OA-containing diet showed a 73% decrease in the DTH reaction to OA and also significantly lower levels of IgE and IgG antibodies against OA compared with the colonized rats fed conventional diet. The dams colonized as adults by the OA-producing E. coli developed IgE anti-lipopolysaccharide antibodies in serum while the pups colonized via the dams at birth did not. Neonatal colonization with an E. coli strain producing OA resulted in increased DTH reactivity against OA and priming for secondary IgE anti-OA response. Feeding the animals an OA-containing diet from weaning abrogated this intestinally induced hypersensitivity and rendered the animals orally tolerant to OA.
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| 5. |
- Dahlman-Höglund, Anna, 1964, et al.
(författare)
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Induction of IgE antibodies and T-cell reactivity to ovalbumin in rats colonized with Escherichia coli genetically manipulated to produce ovalbumin.
- 1992
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Ingår i: Immunology. - 0019-2805. ; 76:2, s. 225-8
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Tidskriftsartikel (refereegranskat)abstract
- The immune response to ovalbumin (OA) and the bacterial antigens, lipopolysaccharide (LPS) and fimbriae were studied in conventional rats colonized from birth with an Escherichia coli strain producing OA. The colonized rats had developed IgE antibodies against OA, but not against the fimbrial or the LPS antigens from the E. coli at 2 months of age. At this time all rats were primed with OA given intracutaneously in Freund's complete adjuvant. Two weeks later the colonized rats showed a 35% greater delayed-type hypersensitivity (DTH) reaction to OA, measured as ear swelling, than the controls. Thus bacteria carrying antigens resembling potential allergens might aggravate, or participate in the induction of allergic symptoms. In addition such bacteria could be efficient vaccine vectors in protection against parasites. The study illustrates the importance of the mode of antigen presentation for the subsequent immune response.
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| 6. |
- Karlsson, Malin, et al.
(författare)
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"Tolerosomes” are produced by intestinal epithelial cells
- 2001
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Ingår i: European Journal of Immunology. ; 31, s. 2892-2900
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Tidskriftsartikel (refereegranskat)abstract
- The development of immunological tolerance to orally fed antigens depends on the sampling, processing and transportation events followed in the intestinal epithelium. We present here a description of a ’’tolerosome’’: a supra-molecular, exosome-like structure assembled in and released from the small intestinal epithelial cell. The tolerosome is a e 40 nm large vesicular structure that carries MHC class II (MHC II) with bound antigenic peptides sampled from the gut lumen. Tolerosomes isolated from serum shortly after antigen feeding or from an in vitro pulsed intestinal epithelial cell line are fully capable of inducing antigen specific tolerance in naive recipient animals. Purified tolerosomes represent a structure by which fed antigens can be efficiently presented to the immune system. Removal of the tolerosomes from serum by ultracentrifugation or absorption of MHC II results in abrogated tolerance development.
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| 7. |
- Alizadehgharib, Sara, et al.
(författare)
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Effects of the methacrylate/acrylate monomers HEMA, TEGDMA, DEGDA, and EMA on the immune system
- 2017
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Ingår i: Clinical and Experimental Dental Research. - : Wiley. - 2057-4347. ; 3:6, s. 227-234
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Tidskriftsartikel (refereegranskat)abstract
- Incomplete curing of dental fillings may lead to leakage of methacrylate/acrylate monomers, which may come in contact with different cells of the immune system in oral tissues. Very little is known about the different immunologic effects caused by these methacrylates/acrylates. The objective of the present study was to study if and how the methacrylate/acrylate monomers ethyl methacrylate (EMA) and diethylene glycol diacrylate (DEGDA) affect the immune system in vivo and in vitro in comparison to 2-hydroxyethyl methacrylate (HEMA) and triethylene glycol dimethacrylate (TEGDMA). Human peripheral blood mononuclear cells were exposed to the different monomers (500 and 1000 μM) for 24 hr in vitro. BioPlex Pro™ assays were used for cytokine analysis. In vivo, BALB/c mice were immunized subcutaneously at the base of the tail with HEMA, TEGDMA, EMA, or DEGDA in combination with ovalbumin (OVA) in order to study adjuvant properties of the 4 monomers. Peripheral blood mononuclear cells exposed to DEGDA had viability less than 50% of the cells. A pattern was observed where the levels of most cytokines were elevated after exposure to HEMA or TEGDMA. Since that, many cells died after DEGDA-exposure, the only observed cytokine secretion was a significantly increased production of interleukin-18. In the in vivo experiments, all mice immunized with DEGDA died after the booster injection. Mice receiving OVA in combination with HEMA, TEGDMA, or EMA developed a higher immunoglobulin G anti-OVA antibody levels compared to the group immunized with OVA alone. We could not demonstrate any significant difference in antibody levels among the mice receiving the various methacrylate/acrylate monomers. The different monomers affected the production, increase and decrease, of different cytokines in vitro but resulted also in vivo in increased antibody production and T-cell activity.
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| 8. |
- Alizadehgharib, Sara, et al.
(författare)
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Immunological response of human leucocytes after exposure to lipopolysaccharides from Porphyromonas gingivalis.
- 2021
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Ingår i: Clinical and experimental dental research. - : Wiley. - 2057-4347. ; 7:4, s. 531-538
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Tidskriftsartikel (refereegranskat)abstract
- Porphyromonas gingivalis (P. gingivalis) is a gram-negative bacterium and an important etiologic agent of periodontitis. P. gingivalis releases outer membrane vesicles containing lipopolysaccharides (LPS), which can penetrate periodontal tissues. Once in the periodontal tissues and in contact with immune cells, it may participate in the destructive innate host response associated with the disease. The exact mechanism of P. gingivalis LPS in the disease process is not clear, but it is known to affect a variety of immune responses.To investigate how LPS from P. gingivalis affect neutrophil extracellular trap (NET) formation, cell death and production of cytokines from human neutrophils and peripheral mononuclear blood mononuclear cells (PBMCs).Isolated neutrophils and PBMCs were cultured with LPS from P. gingivalis or Escherichia coli (E. coli) (control). The NET formation was measured using Sytox green stain. Cell death of neutrophils and PBMCs was analyzed using flow cytometry or Sytox green stain. Cytokine production was measured using enzyme-linked immunosorbent assay (ELISA) kit or Bio-Plex assay.Exposure to LPS from P. gingivalis and E. coli caused significantly lower cell death in neutrophils. NETs were formed after exposure to the two different LPS. In PBMCs, exposure to P. gingivalis and E. coli LPS caused increased levels of IL-1β and IL-6 compared to unstimulated controls. Increased cell death in PBMCs after exposure to LPS from E. coli in comparison to LPS from P. gingivalis and unstimulated controls was also observed.LPS from P. gingivalis has the ability to affect both human neutrophils and PBMCs with regard to cytokine production, cell death and production of NETs. LPS from P. gingivalis could be involved in the pathogenesis of periodontitis, and our results may contribute information regarding possible markers for diagnosis and targets for treatment of periodontal disease.
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| 9. |
- Alizadehgharib, Sara, et al.
(författare)
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The effects of the dental methacrylates TEGDMA, Bis-GMA, and UDMA on neutrophils in vitro.
- 2020
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Ingår i: Clinical and experimental dental research. - : Wiley. - 2057-4347. ; 6:4, s. 439-447
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Tidskriftsartikel (refereegranskat)abstract
- The prevalent usage of methacrylates in modern dentistry demands good knowledge of their biological impacts. While there have been several studies demonstrating the effects of different methacrylic monomers on mononuclear white blood cells, very little is known about the effects caused by these monomers on neutrophilic granulocytes. The objective of this study was to add novel knowledge about how neutrophils are affected by exposure to triethylene glycol dimethacrylate (TEGDMA), urethane dimethacrylate (UDMA), and bisphenol A glycol dimethacrylate (Bis-GMA) alone or in combinations.Isolated neutrophils were cultured in the presence or absence of methacrylates. The IL-8 release was measured using a DuoSet ELISA development kit. Apoptosis and necrosis were analyzed using flow cytometry. The formation of neutrophil extracellular traps (NETs) was investigated using Sytox green DNA staining combined with microscopically examination of released DNA and myeloperoxidase (MPO).The release of IL-8 was significantly increased after exposure to TEGDMA, Bis-GMA, UDMA, or TEGDMA in combination with Bis-GMA or UDMA compared to the unstimulated controls. Exposure to TEGDMA, UDMA, and Bis-GMA for 24hr separately or in combination did not affect apoptosis or necrosis of the exposed neutrophils. NET structures were formed by neutrophils after exposure to the different combinations of the methacrylates.The combination of TEGDMA and Bis-GMA had a synergistic proinflammatory effect on neutrophils by increasing the release of IL-8 and the formation of NET structures. The changes in the normal functions of neutrophils caused by methacrylate exposure may lead to altered inflammatory response and relate to previously reported adverse immune reactions caused by these substances.
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| 10. |
- Alizadehgharib, Sara, et al.
(författare)
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The Immunomodulatory Properties of 2-Hydroxyethyl Methacrylate are Mediated by the NLRP3 Inflammasome.
- 2018
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Ingår i: The journal of adhesive dentistry. - 1461-5185. ; 20:3, s. 213-220
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Tidskriftsartikel (refereegranskat)abstract
- The methacrylate monomer 2-hydroxyethyl methacrylate (HEMA), commonly used in dentistry, has multiple effects on the immune system. This study examined whether HEMA affects the immune system by inducing formation of the NLRP3 inflammasome.Human peripheral blood mononuclear cells (PBMCs) and the human monocyte cell line THP1 were cultured with or without 1000 μM HEMA. To block NLRP3 inflammasome activation, 130 mM KCl was also added to some of the cultures. For the in vivo studies, two different experimental setups were used. In the first experimental setup, mice were injected subcutaneously at the base of the tail with 20 μmol HEMA with or without 100 mM KCl. After 3 weeks, the animals were given an identical booster injection. Two weeks after the last injection, the mice were sacrificed and splenectomized. In the second experimental setup, HEMA (20 μmol), with or without 100 mM KCl, was injected subcutaneously into the tails of BALB/c mice. The mice were given two similar injections at 3-week intervals to allow evaluation of the local inflammation induced by HEMA. After the last inoculation, the injection site was examined daily for 4 days, after which the mice were sacrificed.Cultures of PBMCs and THP1 cells exposed to HEMA in vitro produced more IL-1ß and IL-18 than did control cells. Increased extracellular concentration of KCl inhibited the secretion of IL-1ß. HEMA exposure did not induce cytokine production in variants of the THP1 cell line unable to form the NLRP3 inflammasome. For the first experimental setup, the level of unstimulated basic splenocyte proliferation in vitro was significantly higher in cultures from mice exposed in vivo to HEMA only than in cultures from mice injected with HEMA plus KCl. In the second experimental setup of the in vivo studies, the HEMA-treated mice developed more pronounced inflammation at the site of injection compared to the group of mice given HEMA plus KCl.HEMA affects the immune system by inducing formation of the NLRP3 inflammasome.
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