| 1. |
- Quiding-Järbrink, Marianne, 1964, et al.
(författare)
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Decreased IgA antibody production in the stomach of gastric adenocarcinoma patients.
- 2009
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Ingår i: Clinical immunology. - : Elsevier BV. - 1521-7035 .- 1521-6616. ; 131:3, s. 463-71
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Tidskriftsartikel (refereegranskat)abstract
- Gastric adenocarcinoma is closely associated with Helicobacter pylori infection. It is also much more frequent in patients with common variable immunodeficiency or selective IgA-deficiency than in the general population. To investigate a possible link between local antibody production and gastric tumors, we studied gastric B cell infiltration and local IgA production in patients with H. pylori induced gastric adenocarcinomas. These studies showed that total and H. pylori-specific IgA antibody levels were substantially lower in gastric tissue from the cancer patients compared to those from asymptomatic H. pylori carriers. However, serum IgA levels were similar in the cancer patients and asymptomatic carriers. As could be expected, H. pylori infected asymptomatic carriers had considerably increased IgA antibody levels compared to uninfected subjects. We conclude that patients suffering from gastric adenocarcinoma have a dramatically decreased local IgA production in the stomach compared to asymptomatic H. pylori infected individuals.
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| 2. |
- Andersson, M, et al.
(författare)
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Adequate iodine nutrition in Sweden: a cross-sectional national study of urinary iodine concentration in school-age children.
- 2009
-
Ingår i: European journal of clinical nutrition. - : Springer Science and Business Media LLC. - 0954-3007 .- 1476-5640. ; 63:7, s. 828-34
-
Tidskriftsartikel (refereegranskat)abstract
- Background/Objectives:Sweden has a long-standing salt iodization program; however, its effects on iodine intake have never been monitored on a national level. The objective of this study was to evaluate iodine nutrition in the Swedish population by measuring the urinary iodine concentration (UIC) in a national sample of Swedish school-age (6-12 years of age) children.Subjects/Methods:A stratified probability proportionate to size cluster sampling method was used to obtain a representative national sample of school-age children from 30 clusters. Spot urine samples were collected for UIC analysis using a modified Sandell-Kolthoff method.Results:The median UIC of the children (n=857) was 125 mug/l (range 11-757 mug/l). The proportion of children with a UIC <100 mug/l was 30.0% and the proportion of children with a UIC <50 and >300 mug/l was 5.5 and 3.0%, respectively.Conclusions:The iodine nutritional status of the Swedish population is adequate. Iodized table salt remains the main dietary source of iodine in Swedish diet. Recommendations to reduce total salt intake in the population urge increased use of iodized salt in the production of processed foods. Pregnant and lactating women with high iodine requirements may still be at risk for low iodine intake. This study will serve as the basis for future monitoring of iodine nutritional status in Sweden.European Journal of Clinical Nutrition advance online publication, 10 September 2008; doi:10.1038/ejcn.2008.46.
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| 3. |
- Bäckström, Malin, 1967, et al.
(författare)
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Increased understanding of the biochemistry and biosynthesis of MUC2 and other gel-forming mucins through the recombinant expression of their protein domains.
- 2013
-
Ingår i: Molecular biotechnology. - : Springer Science and Business Media LLC. - 1559-0305 .- 1073-6085. ; 54:2, s. 250-6
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Tidskriftsartikel (refereegranskat)abstract
- The gel-forming mucins are large and heavily O-glycosylated proteins which build up mucus gels. The recombinant production of full-length gel-forming mucins has not been possible to date. In order to study mucin biosynthesis and biochemistry, we and others have taken the alternative approach of constructing different recombinant proteins consisting of one or several domains of these large proteins and expressing them separately in different cell lines. Using this approach, we have determined that MUC2, the intestinal gel-forming mucin, dimerizes via its C-terminal cysteine-knot domain and also trimerizes via one of the N-terminal von Willebrand D domains. Both of these interactions are disulfide bond mediated. Via this assembly, a molecular network is built by which the mucus gel is formed. Here we discuss not only the functional understanding obtained from studies of the recombinant proteins, but also highlight the difficulties encountered when these proteins were produced recombinantly. We often found an accumulation of the proteins in the ER and consequently no secretion. This was especially apparent when the cysteine-rich domains of the N- and C-terminal parts of the mucins were expressed. Other proteins that we constructed were either not secreted or not expressed at all. Despite these problems, the knowledge of mucin biosynthesis and assembly has advanced considerably through the studies of these recombinant proteins.
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| 4. |
- Ehrencrona, Erik, et al.
(författare)
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The IgGFc-binding protein FCGBP is secreted with all GDPH sequences cleaved but maintained by interfragment disulfide bonds
- 2021
-
Ingår i: Journal of Biological Chemistry. - : Elsevier BV. - 0021-9258. ; 297:1
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Tidskriftsartikel (refereegranskat)abstract
- Mucus forms an important protective barrier that minimizes bacterial contact with the colonic epithelium. Intestinal mucus is organized in a complex network with several specific proteins, including the mucin-2 (MUC2) and the abundant IgGFc-binding protein, FCGBP. FCGBP is expressed in all intestinal goblet cells and is secreted into the mucus. It is comprised of repeated von Willebrand D (vWD) domain assemblies, most of which have a GDPH amino acid sequence that can be autocatalytically cleaved, as previously observed in the mucins MUC2 and mucin-5AC. However, the functions of FCGBP in the mucus are not understood. We show that all vWD domains of FCGBP with a GDPH sequence are cleaved and that these cleavages occur early during biosynthesis in the endoplasmic reticulum. All cleaved fragments, however, remain connected via a disulfide bond within each vWD domain. This cleavage generates a C-terminal-reactive Asp-anhydride that could react with other molecules, such as MUC2, but this was not observed. Quantitative analyses by MS showed that FCGBP was mainly soluble in chaotropic solutions, whereas MUC2 was insoluble, and most of the secreted FCGBP was not covalently bound to MUC2. Although FCGBP has been suggested to bind immunoglobulin G, we were unable to reproduce this binding in vitro using purified proteins. In conclusion, while the function of FCGBP is still unknown, our results suggest that it does not contribute to covalent crosslinking in the mucus, nor incorporate immunoglobulin G into mucus, instead the single disulfide bond linking each fragment could mediate controlled dissociation.
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| 5. |
- Hansson, Malin, 1967, et al.
(författare)
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CCL28 is increased in human Helicobacter pylori induced gastritis and mediates recruitment of gastric IgA-secreting cells.
- 2008
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Ingår i: Infection and Immunity. - 0019-9567. ; 76:7, s. 3304-11
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Tidskriftsartikel (refereegranskat)abstract
- Human Helicobacter pylori infection gives rise to an active chronic gastritis and is a major risk factor for the development of duodenal ulcer disease and gastric adenocarcinoma. The infection is accompanied by a large accumulation of immunoglobulin A (IgA)-secreting cells in the gastric mucosa, and following mucosal immunization only H. pylori-infected volunteers mounted a B-cell response in the gastric mucosa. To identify the signals for recruitment of gastric IgA-secreting cells, we investigated the gastric production of CCL28 (mucosa-associated epithelial chemokine) and CCL25 (thymus-expressed chemokine) in H. pylori-infected and uninfected individuals and the potential of gastric B-cell populations to migrate toward these chemokines. Gastric tissue from H. pylori-infected individuals contained significantly more CCL28 protein and mRNA than that from uninfected individuals, while CCL25 levels remained unchanged. Chemokine-induced migration of gastric lamina propria lymphocytes isolated from patients undergoing gastric resection was then assessed using the Transwell system. IgA-secreting cells and IgA+ memory B cells from H. pylori-infected tissues migrated toward CCL28 but not CCL25, while the corresponding cells from uninfected patients did not. Furthermore, IgG-secreting cells from H. pylori-infected patients did not migrate to CCL28 but instead to CXCL12 (SDF-1). However, chemokine receptor expression did not correlate to the migratory pattern of the different B-cell populations. These studies are the first to show increased CCL28 production during gastrointestinal infection in humans and provide an explanation for the large influx of IgA-secreting cells to the gastric mucosa in H. pylori-infected individuals.
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| 6. |
- Hansson, Malin, 1967, et al.
(författare)
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DC-LAMP(+) Dendritic Cells Are Recruited to Gastric Lymphoid Follicles in Helicobacter pylori-Infected Individuals
- 2013
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Ingår i: Infection and Immunity. - : American Society for Microbiology. - 0019-9567 .- 1098-5522. ; 81:10, s. 3684-3692
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Tidskriftsartikel (refereegranskat)abstract
- Infection with Helicobacter pylori is associated with development of ulcer disease and gastrointestinal adenocarcinoma. The infection leads to a large infiltration of immune cells and the formation of organized lymphoid follicles in the human gastric mucosa. Still, the immune system fails to eradicate the bacteria, and the substantial regulatory T cell (Treg) response elicited is probably a major factor permitting bacterial persistence. Dendritic cells (DCs) are professional antigen-presenting cells that can activate naive T cells, and maturation of DCs is crucial for the initiation of primary immune responses. The aim of this study was to investigate the presence and localization of mature human DCs in H. pylori-infected gastric mucosa. Gastric antral biopsy specimens were collected from patients with H. pylori-associated gastritis and healthy volunteers, and antrum tissue was collected from patients undergoing gastric resection. Immunohistochemistry and flow cytometry showed that DCs expressing the maturation marker dendritic cell lysosome-associated membrane glycoprotein (DC-LAMP; CD208) are enriched in the H. pylori-infected gastric mucosa and that these DCs are specifically localized within or close to lymphoid follicles. Gastric DC-LAMP-positive (DC-LAMP(+)) DCs express CD11c and high levels of HLA-DR but little CD80, CD83, and CD86. Furthermore, immunofluorescence analyses demonstrated that DC-LAMP(+) DCs are in the same location as FoxP3-positive putative Tregs in the follicles. In conclusion, we show that DC-LAMP(+) DCs with low costimulatory capacity accumulate in the lymphoid follicles in human H. pylori-infected gastric tissue, and our results suggest that Treg-DC interactions may promote chronic infection by rendering gastric DCs tolerogenic.
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| 7. |
- Johansson, Malin E V, 1971, et al.
(författare)
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Composition and functional role of the mucus layers in the intestine.
- 2011
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Ingår i: Cellular and Molecular Life Sciences. - : Springer Science and Business Media LLC. - 1420-682X .- 1420-9071. ; 68, s. 3635-3641
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Forskningsöversikt (refereegranskat)abstract
- In discussions on intestinal protection, the protective capacity of mucus has not been very much considered. The progress in the last years in understanding the molecular nature of mucins, the main building blocks of mucus, has, however, changed this. The intestinal enterocytes have their apical surfaces covered by transmembrane mucins and the whole intestinal surface is further covered by mucus, built around the gel-forming mucin MUC2. The mucus of the small intestine has only one layer, whereas the large intestine has a two-layered mucus where the inner, attached layer has a protective function for the intestine, as it is impermeable to the luminal bacteria.
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| 8. |
- Kindlund, Bert, 1969, et al.
(författare)
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FOXP3-expressing CD4(+) T-cell numbers increase in areas of duodenal gastric metaplasia and are associated to CD4(+) T-cell aggregates in the duodenum of Helicobacter pylori-infected duodenal ulcer patients.
- 2009
-
Ingår i: Helicobacter. - : Wiley. - 1523-5378 .- 1083-4389. ; 14:3, s. 192-201
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: We have previously demonstrated that Helicobacter pylori infection is associated with an increased number of CD4(+)CD25(high) regulatory T cells in the gastric and duodenal mucosa. In this study, we determined the number and localization of CD4(+) cells expressing the regulatory T-cell-specific transcription factor FOXP3 in the antrum and duodenum of duodenal ulcer patients, asymptomatic carriers, and uninfected individuals. We also determined gene expression levels of FOXP3 as well as anti- and proinflammatory cytokines before and after H. pylori eradication. METHODS: Cellular FOXP3 expression was studied by immunofluorescence and flow cytometry, and transcription levels of FOXP3, interleukin (IL)-10, transforming growth factor-beta, CD4, and interferon-gamma were analyzed by real-time reverse transcription-polymerase chain reaction. RESULTS: We found an increased (6-fold) frequency of CD4(+)FOXP3(+) T cells in H. pylori-infected gastric mucosa; interestingly 26% of these cells did not co-express CD25. The increase of FOXP3-expressing T cells in the antrum of infected individuals was dependent on the presence of H. pylori, since eradication therapy resulted in 4-fold lower levels of FOXP3 and IL-10 mRNA in the antrum. Furthermore, higher numbers of CD4(+)FOXP3(+) T cells were found in areas of duodenal gastric metaplasia in the duodenum of duodenal ulcer patients compared to duodenal gastric metaplasia of asymptomatic individuals and healthy mucosa in both patient groups. In duodenal ulcer patients, the CD4(+)FOXP3(+) T cells were more highly associated to aggregates in the duodenal mucosa. CONCLUSION: The numbers of CD4(+)FOXP3(+) T cells are increased and localized in CD4(+) T-cell aggregates in areas of duodenal gastric metaplasia in duodenal ulcer patients.
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| 9. |
- Oertli, Mathias, et al.
(författare)
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DC-derived IL-18 drives Treg differentiation, murine Helicobacter pylori-specific immune tolerance, and asthma protection.
- 2012
-
Ingår i: The Journal of clinical investigation. - 1558-8238. ; 122:3, s. 1082-96
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Tidskriftsartikel (refereegranskat)abstract
- Persistent colonization with the gastric bacterial pathogen Helicobacter pylori causes gastritis and predisposes infected individuals to gastric cancer. Conversely, it is also linked to protection from allergic, chronic inflammatory, and autoimmune diseases. We demonstrate here that H. pylori inhibits LPS-induced maturation of DCs and reprograms DCs toward a tolerance-promoting phenotype. Our results showed that DCs exposed to H. pylori in vitro or in vivo failed to induce T cell effector functions. Instead, they efficiently induced expression of the forkhead transcription factor FoxP3, the master regulator of Tregs, in naive T cells. Depletion of DCs in mice infected with H. pylori during the neonatal period was sufficient to break H. pylori-specific tolerance. DC depletion resulted in improved control of the infection but also aggravated T cell-driven immunopathology. Consistent with the mouse data, DCs infiltrating the gastric mucosa of human H. pylori carriers exhibited a semimature DC-SIGN(+)HLA-DR(hi)CD80(lo)CD86(lo) phenotype. Mechanistically, the tolerogenic activity of H. pylori-experienced DCs was shown to require IL-18 in vitro and in vivo; DC-derived IL-18 acted directly on T cells to drive their conversion to Tregs. CD4(+)CD25(+) Tregs from infected wild-type mice but not Il18(-/-) or Il18r1(-/-) mice prevented airway inflammation and hyperresponsiveness in an experimental model of asthma. Taken together, our results indicate that tolerogenic reprogramming of DCs ensures the persistence of H. pylori and protects against allergic asthma in a process that requires IL-18.
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| 10. |
- Recktenwald, Christian V, et al.
(författare)
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The structure of the second CysD domain of MUC2 and role in mucin organization by transglutaminase-based cross-linking
- 2024
-
Ingår i: Cell Reports. - 2211-1247. ; 43
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Tidskriftsartikel (refereegranskat)abstract
- The MUC2 mucin protects the colonic epithelium by a two-layered mucus with an inner attached bacteria-free layer and an outer layer harboring commensal bacteria. CysD domains are 100 amino-acid-long sequences containing 10 cysteines that separate highly O-glycosylated proline, threonine, serine (PTS) regions in mucins. The structure of the second CysD, CysD2, of MUC2 is now solved by nuclear magnetic resonance. CysD2 shows a stable stalk region predicted to be partly covered by adjacent O-glycans attached to neighboring PTS sequences, whereas the CysD2 tip with three flexible loops is suggested to be well exposed. It shows transient dimer interactions at acidic pH, weakened at physiological pH. This transient interaction can be stabilized in vitro and in vivo by transglutaminase 3-catalyzed isopeptide bonds, preferring a specific glutamine residue on one flexible loop. This covalent dimer is modeled suggesting that CysD domains act as connecting hubs for covalent stabilization of mucins to form a protective mucus.
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| 11. |
- van der Post, Sjoerd, 1981, et al.
(författare)
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Site-specific O-glycosylation on the MUC2 mucin protein inhibits cleavage by the Porphyromonas gingivalis secreted cysteine protease (RgpB).
- 2013
-
Ingår i: The Journal of biological chemistry. - 1083-351X. ; 288:20, s. 14636-46
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Tidskriftsartikel (refereegranskat)abstract
- The colonic epithelial surface is protected by an inner mucus layer that the commensal microflora cannot penetrate. We previously demonstrated that Entamoeba histolytica secretes a protease capable of dissolving this layer that is required for parasite penetration. Here, we asked whether there are bacteria that can secrete similar proteases. We screened bacterial culture supernatants for such activity using recombinant fragments of the MUC2 mucin, the major structural component, and the only gel-forming mucin in the colonic mucus. MUC2 has two central heavily O-glycosylated mucin domains that are protease-resistant and has cysteine-rich N and C termini responsible for polymerization. Culture supernatants of Porphyromonas gingivalis, a bacterium that secretes proteases responsible for periodontitis, cleaved the MUC2 C-terminal region, whereas the N-terminal region was unaffected. The active enzyme was isolated and identified as Arg-gingipain B (RgpB). Two cleavage sites were localized to IR↓TT and NR↓QA. IR↓TT cleavage will disrupt the MUC2 polymers. Because this site has two potential O-glycosylation sites, we tested whether recombinant GalNAc-transferases (GalNAc-Ts) could glycosylate a synthetic peptide covering the IRTT sequence. Only GalNAc-T3 was able to glycosylate the second Thr in IRTT, rendering the sequence resistant to cleavage by RgpB. Furthermore, when GalNAc-T3 was expressed in CHO cells expressing the MUC2 C terminus, the second threonine was glycosylated, and the protein became resistant to RgpB cleavage. These findings suggest that bacteria can produce proteases capable of dissolving the inner protective mucus layer by specific cleavages in the MUC2 mucin and that this cleavage can be modulated by site-specific O-glycosylation.
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| 12. |
- Ander, Magnus, et al.
(författare)
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Elchockvapen som hjälpmedel vid polisiära ingripanden : En vetenskaplig utvärdering av Polismyndighetens försöksverksamhet med elchockvapen 2018-2019
- 2020
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- BAKGRUND: Ur ett internationellt perspektiv har det, inom polisen, under de senaste åren skett en ökning i användandet av mindre dödliga vapen. Dessa vapen används för att ta kontroll över potentiellt farliga och icke samarbetsvilliga personer. Ett vanligt förekommande mindre dödligt vapen är elchockvapen (ECV). Elchockvapen har fram till 2018 inte använts i Sverige, men Polismyndigheten har under åren 2018–2019 genomfört en försöksverksamhet med ECV.SYFTE: Syftet med undersökningen var att utvärdera Polismyndighetens försöksverksamhet med ECV, samt att undersöka vilken legitimitet polisens användning av ECV har bland allmänheten.METOD: Både kvantitativa och kvalitativa data samlades in för att utvärdera försöket med ECV. Mätningar före, under, och i slutet av försöksverksamheten genomfördes med hjälp av en enkät. Enkäten besvarades av två grupper av poliser; en grupp som ingick i försöksverksamheten med ECV samt en kontrollgrupp poliser som inte ingick i försöksverksamheten. För att fördjupa förståelsen för enkätresultaten genomfördes djupintervjuer och fokusgruppsintervjuer med poliser som hade erfarenhet av ECV under försöksverksamheten. För att undersöka legitimitetsaspekter utifrån ett medborgarperspektiv genomfördes fokusgrupper med deltagare från allmänheten. Data från Polisens arbetsskadesystem LISA inhämtades för att undersöka ECV:s inverkan på skador hos poliserna.RESULTAT: Enkätresultaten visade inga skillnader mellan delaktiga och kontrollgrupp när det gäller upplevelse av stressfulla situationer. Upplevelsen av trygghet vid ingripanden med hög grad av motstånd eller när polisen blir fysisk angripen har dock ökat för de poliser som deltagit i ECVförsöket, jämfört med kontrollgruppen. Intervjuresultaten åskådliggör också att tillgången till ECV bidrar till att minska upplevelsen av stress i våldsamma situationer genom att ECV ökar tryggheten i sådana situationer. Intervjuresultaten påvisar även att tillgången till ECV gör att man slipper använda andra potentiellt skadligare våldshjälpmedel såsom fysiska metoder och skjutvapen. Enkätresultatet visar ingen skillnad mellan de som ingick i försöksverksamheten och kontrollgruppen när det gäller att utsättas för hot, våld eller motstånd, eller att polis eller motpart blir skadade. Resultaten från intervjuer och fokusgrupper synliggör att poliserna upplever att ECV fyller en viktig funktion. Poliserna ser enbart fördelar med ECV och vissa menar att det är det bästa verktyg som de har fått. ECV upplevs kunna rädda liv, minska skador på polis och motpart, samt förbättra arbetsmiljön för poliser. Intervjuer och fokusgrupper pekar på att deltagarna upplever att ECV har en deeskalerande inverkan, vilket både kan minska våldsanvändningen, och förebygga våld mot polisen. Enkät och intervjuresultaten indikerar att ECV bidrar till en minskad användning av andra hjälpmedel såsom batong och pepparspray, vilka ofta ger mer skador på både motpart och polis. Deltagarna från allmänheten har uppfattningen att ECV är ett effektivt och bra verktyg för polisen, men lyfter vikten av att det finns en lyhördhet gällande vilka situationer som den används i och mot vem.SLUTSATSER: Utifrån våra enkätresultat är det svårt att dra några säkra slutsatser kring hur användandet av ECV inverkar på skador hos poliser och motpart. Erfarenheterna bland de delaktiga är dock att risken för våld och skador minskar markant, vilket är en viktig indikator. Tillgången till ECV kan öka trygghet och minska stress i ingripandesituationer där kraftigt motstånd och våld förekommer. ECV kan även minska användandet av pepparspray och batong, och det finns indikationer på att ECV har använts istället för skjutvapen. ECV kan underlätta val av hjälpmedel vid ingripanden med hög grad av hot och våld och kan ha en deeskalerande inverkan. Polisens användande av våldshjälpmedel, inklusive ECV, upplevs berättigat av informanterna från allmänheten.
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| 13. |
- Bäckström, Malin, 1967, et al.
(författare)
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Recombinant MUC1 mucin with a breast cancer-like O-glycosylation produced in large amounts in Chinese-hamster ovary cells.
- 2003
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Ingår i: The Biochemical journal. - 1470-8728. ; 376:Pt 3, s. 677-86
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Tidskriftsartikel (refereegranskat)abstract
- We have developed an expression system for the production of large quantities of recombinant MUC1 mucin in CHO-K1 (Chinese-hamster ovary K1) cells. The extracellular part of human MUC1, including 16 MUC1 tandem repeats, was produced as a fusion protein with murine IgG Fc, with an intervening enterokinase cleavage site for the removal of the Fc tail. Stable MUC1-IgG-producing CHO-K1 clones were generated and were found to secrete MUC1-IgG into the culture medium. After adaptation to suspension culture in protein-free medium in a bioreactor, the fusion protein was secreted in large quantities (100 mg/l per day) into the culture supernatant. From there, MUC1 could be purified to homogeneity using a two-step procedure including enterokinase cleavage and ion-exchange chromatography. Capillary liquid chromatography MS of released oligosaccharides from CHO-K1-produced MUC1 identified the main O-glycans as Galbeta1-3GalNAc (core 1) and mono- and di-sialylated core 1. The glycans occupied on average 4.3 of the five potential O-glycosylation sites in the tandem repeats, as determined by nano-liquid chromatography MS of partially deglycosylated Clostripain-digested protein. A very similar O-glycan profile and site occupancy was found in MUC1-IgG produced in the breast carcinoma cell line T47D, which has O-glycosylation typical for breast cancer. In contrast, MUC1-IgG produced in another breast cancer cell line, MCF-7, showed a more complex pattern with both core 1- and core 2-based O-glycans. This is the first reported production of large quantities of recombinant MUC1 with a breast cancer-like O-glycosylation that could be used for the immunotherapy of breast cancer.
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| 14. |
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| 15. |
- Domino, Steven E, et al.
(författare)
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Cervical mucins carry alpha(1,2)fucosylated glycans that partly protect from experimental vaginal candidiasis.
- 2009
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Ingår i: Glycoconjugate journal. - : Springer Science and Business Media LLC. - 1573-4986 .- 0282-0080. ; 26:9, s. 1125-34
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Tidskriftsartikel (refereegranskat)abstract
- Cervical mucins are glycosylated proteins that form a protective cervical mucus. To understand the role of mucin glycans in Candida albicans infection, oligosaccharides from mouse cervical mucins were analyzed by liquid chromatography-mass spectrometry. Cervical mucins carry multiple alpha(1-2)fucosylated glycans, but alpha(1,2)fucosyltransferase Fut2-null mice are devoid of these epitopes. Epithelial cells in vaginal lavages from Fut2-null mice lacked Ulex europaeus agglutinin-1 (UEA-I) staining for alpha(1-2)fucosylated glycans. Hysterectomy to remove cervical mucus eliminated UEA-I and acid mucin staining in vaginal epithelial cells from wild type mice indicating the cervix as the source of UEA-I positive epithelial cells. To assess binding of alpha(1-2) fucosylated glycans on C. albicans infection, an in vitro adhesion assay was performed with vaginal epithelial cells from wild type and Fut2-null mice. Vaginal epithelial cells from Fut2-null mice were found to bind increased numbers of C. albicans compared to vaginal epithelial cells obtained from wild type mice. Hysterectomy lessened the difference between Fut2-null and wild type mice in binding of C. ablicans in vitro and susceptibility to experimental C. albicans vaginitis in vivo. We generated a recombinant fucosylated MUC1 glycanpolymer to test whether the relative protection of wild type mice compared to Fut2-null mice could be mimicked with exogenous mucin. While a small portion of the recombinant MUC1 epitopes displayed alpha(1-2)fucosylated glycans, the predominant epitopes were sialylated due to endogenous sialyltransferases in the cultured cells. Intravaginal instillation of recombinant MUC1 glycanpolymer partially reduced experimental yeast vaginitis suggesting that a large glycanpolymer, with different glycan epitopes, may affect fungal burden.
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| 16. |
- Ganetz, Hillevi, et al.
(författare)
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#metoo – ett tvärsnitt genom samhället
- 2022
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Ingår i: Maktordningar och motstånd. - Lund : Nordic Academic Press. - 9789189361492 ; , s. 7-20
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 17. |
- Ghazinour, Mehdi, 1967-, et al.
(författare)
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Den psykiska hälsan hos poliser som arbetar i yttre tjänst i särskilt utsatta områden
- 2021
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Ingår i: Socialmedicinsk Tidskrift. - : Stiftelsen Socialmedicinsk tidskrift. - 0037-833X. ; 98:2, s. 290-302
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Tidskriftsartikel (refereegranskat)abstract
- Artikelns syfte är att belysa den psykiska hälsan hos svenska poliser som arbetar i yttre tjänst. Polisernas psykiska hälsa är ett viktigt forskningsområde med tanke på hur polisen arbetar i samhället. Att utföra enkla och svåra arbetsuppgifter ställer höga krav på polisens mentala processer. I den här artikeln uppmärksammar vi poliser i yttre tjänst som arbetar i särskilt utsatta områden i Stockholmregionen. Det självskattade frågeformuläret DSM-5 om psykisk hälsa har insamlats och analyserats med hjälp av beskrivande statistik. Resultatet visar att stigande ålder och att leva i en parrelation är skyddsfaktorer mot psykisk ohälsa hos dessa poliser.
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| 18. |
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| 19. |
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| 20. |
- Hansson, Jonas, 1971-, et al.
(författare)
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Coercive measures against minors in the Swedish asylum process : legal uncertainty, ambivalence and experiences of intrusiveness
- 2023
-
Ingår i: Nordic Journal of Social Research. - : Universitetsforlaget. - 1892-2783. ; 14:1, s. 1-21
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Tidskriftsartikel (refereegranskat)abstract
- Asylum-seeking minors are viewed as particularly vulnerable but are still exposed to coercive measures permitted by law. This study analyses Swedish Police Authority and Swedish Migration Agency officials’ perceptions of coercive measures towards minors in the asylum process in light of the Swedish law, and raises minors’ own voices on their experiences of coercive measures. Qualitative interviews were performed with 1) officials at the Swedish Police Authority and Swedish Migration Agency who manage and use coercive actions against minors and 2) former minors with experiences of being subjected to coercive measures. Based on a thematic analysis, the results illustrate how the officials’ perceptions about coercive measures are characterized by uncertainty and ambivalence. The minors expressed the importance of how they were treated during the asylum process rather than the coercive measure as such. Swedish law regulating coercive measures needs clarifications to give sufficient guidance for practice.
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| 21. |
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| 22. |
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| 23. |
- Hansson, Karin, 1967-, et al.
(författare)
-
#konstnärligfrihet : reifikation som förtryckshandling och motstrategi
- 2022
-
Ingår i: Tidskrift för Genusvetenskap. - : Föreningen Tidskrift för genusvetenskap. - 1654-5443 .- 2001-1377. ; 43:1, s. 49-71
-
Tidskriftsartikel (refereegranskat)abstract
- In the autumn of 2017, more than 2,000 female and non-binary artists and designers in Sweden joined forces in the group #konstnärligfrihet [artistic freedom] to share experiences of sexism, sexual harassment, and sexual violence, and to write a joint petition. Using a media timeline and semi-structured interviews, this article aims to situate #metoo in a larger narrative and investigate how sexual harassment within the Swedish art industry is explained and understood by 13 activists and representatives of art institutions.Our results show that there is a strong connection between oppression and economic exploitation. The art industry is characterized by precarious economic and social relations, but also by the idea of the genius and elitist ambitions of standing outside the social order and embodying an unexploitable particularity. This combination is crucial to understanding sexual harassment in the industry. A central theme in the interviews was the feeling of grief and frustration of not being allowed to work freely as an artist but forced to constantly navigate invisible but tangible structures. These structures are maintained performatively through various acts of oppression that are part of a reification process, which systematically limits the livability of the exposed identities. During #metoo, this reification process was counteracted and turned against the oppressors themselves through an objectification of “men” as oppressors. Another finding relates to the interviewees’ understanding of sexual harassment as based upon power. Here, the positions of powerful and powerless were not univocal. As power intertwines with desire and vulnerability, oppressive acts can be multifaceted and ambivalent, and take place as part of a dynamic negotiation of positions in the informal economic system.
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| 24. |
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| 25. |
- Hansson, Karin, 1967-, et al.
(författare)
-
#MeToo in the Manosphere: The Formation of a Counter Discourse on the Swedish Online Forum Flashback
- 2024
-
Ingår i: NORA-NORDIC JOURNAL OF FEMINIST AND GENDER RESEARCH. - : Taylor & Francis. - 0803-8740 .- 1502-394X.
-
Tidskriftsartikel (refereegranskat)abstract
- In Sweden, a relative consensus of liberal and feminist values has long been dominant in public discourse. This could be observed in coverage of the #MeToo movement, which was largely presented in a positive light by legacy media, where critical voices were instead found on alternative and social media. This article contributes to a more nuanced understanding of the impact of #MeToo beyond the mainstream discourse by investigating how #MeToo was discussed on the online forum Flashback during the period spanning October-December 2017. Our findings show how the #MeToo debate in this forum reproduced an anti-feminist discourse from the manosphere but also challenged it, as attitudes towards sexual harassment were negotiated and reframed in dialogue with mainstream media. #MeToo thus also contributed to an increased awareness about sexual harassment in this context. However, while a feminist agenda was being strengthened in legacy media, the anti-feminist views on Flashback became more pronounced. Interestingly, while the dominant feminist discourse around Swedish #MeToo avoided the concept "feminism", it was often used in this counter discourse on Flashback, where it signified a hated, albeit powerful and transformative, force in society.
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| 26. |
- Hansson, Karin, 1967-, et al.
(författare)
-
The significance of feminist infrastructure: #MeToo in the construction industry and the green industry in Sweden
- 2024
-
Ingår i: Gender Work and Organization. - : John Wiley & Sons. - 0968-6673 .- 1468-0432. ; 31:3, s. 1092-1112
-
Tidskriftsartikel (refereegranskat)abstract
- To better understand the interplay between digital activism and feminist infrastructure, this study investigates #MeToo activism in the Swedish construction industry and green industry. Both are industries in transition characterized by a dissonance between formal incentives, that encourage women and others to work in environments previously dominated by white men, and the informal power structures hosting a toxic masculinity. Based on media texts and interviews with key persons from the industries, the article situates #MeToo in a local context and shows how it was embedded in a supportive social, cultural, and technical infrastructure. In both industries, at the time of #MeToo this feminist infrastructure was already in place consisting of: an awareness of the problem of sexual harassment and abuse, knowledge of feminist explanatory models, established feminist online networks, and a supportive feminist culture, which together with widespread digital and feminist literacy became instrumental in the organization of the movement. Social media connected activists and created a critical mass by supporting the uniting of conflicting identity positions around shared differences. The established feminist infrastructure meant that the #MeToo activism, by articulating a widespread affective dissonance, pushed open doors that were already half open and forced them wide. This can explain some of the movement's success in Sweden.
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| 27. |
- Hansson, Malin, 1967, et al.
(författare)
-
Dendritic cells express CCR7 and migrate in response to CCL19 (MIP-3beta) after exposure to Helicobacter pylori
- 2006
-
Ingår i: Microbes Infect. - : Elsevier BV. - 1286-4579. ; 8:3, s. 841-50
-
Forskningsöversikt (refereegranskat)abstract
- Helicobacter pylori infection induces chronic inflammation in the gastric mucosa with a marked increase in the number of lymphoid follicles consisting of infiltrating B and T cells, neutrophils, dendritic cells (DC) and macrophages. It has been suggested that an accumulation of mature DC in the tissue, resulting from a failure of DC to migrate to lymph nodes, may contribute to this chronic inflammation. Migration of DC to lymph nodes is regulated by chemokine receptor CCR7, expressed on mature DC, and the CCR7 ligands CCL19 and CCL21. In this study we analysed the maturation, in vitro migration and cytokine production of human DC after stimulation with live H. pylori. For comparison, DC responses to non-pathogenic Escherichia coli bacteria were also evaluated. Stimulation with H. pylori induced maturation of DC, i.e. up-regulation of the chemokine receptors CCR7 and CXCR4 and the maturation markers HLA-DR, CD80 and CD86. The H. pylori-stimulated DC also induced CD4(+) T-cell proliferation. DC stimulated with H. pylori secreted significantly more interleukin (IL)-12 compared to DC stimulated with E. coli, while E. coli-stimulated DC secreted more IL-10. Despite low surface expression of CCR7 protein following stimulation with H. pylori compared to E. coli, the DC migrated equally well towards CCL19 after stimulation with both bacteria. Thus, we could not detect any failure in the migration of H. pylori stimulated DC in vitro that may contribute to chronic gastritis in vivo, and our results suggest that H. pylori induces maturation and migration of DC to lymph nodes where they promote T cell responses.
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| 28. |
- Hansson, Malin, 1967
(författare)
-
Trafficking of Human Dendritic Cells and B cells in Helicobacter pylori-induced Gastritis
- 2009
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Infection with the bacterium Helicobacter pylori is widespread throughout the world, and is associated with development of gastric and duodenal ulcer disease as well as gastric adenocarcinoma and mucosa associated lymphoid tissue lymphoma. The infection generally leads to a large infiltration of immune cells, among them dendrite cells (DC) and IgA-secreting cells. Even though there is a strong innate and adaptive immune response, the bacteria are not eliminated from the stomach and the infection usually remains throughout life. The inductive site for the adaptive immune responses to H. pylori has not yet been identified and very little is known about the role of DC in the immune defense of the human stomach. The migration of DC from sites of antigen capture in peripheral tissues to the secondary lymphoid organs and the simultaneous maturation are crucial for initiation and amplification of primary immune responses. In this thesis we hypothesized that gastric DC fails to migrate to the lymph node and instead remains in the tissue and contribute to the chronic inflammation. Tissue-specific lymphocyte homing to the intestinal mucosa tissue is dependent on interactions between specific adhesion molecules. These are, however, not changed during H. pylori infection. Instead, we hypothesized that mucosal chemokines contribute to recruitment of B cells to the H. pylori infected gastric mucosa. Therefore, the overall aims of this thesis were to evaluate how H. pylori infection affect the recruitment, functions and migration of DC and to investigate the role of chemokines for B cell homing to the gastric mucosa. We have shown that DC stimulated with live H. pylori in vitro up-regulate the expression of the chemokine receptor CCR7, important for migration to the secondary lymphoid tissue, and that H. pylori stimulated DC migrate toward the CCR7 ligand CCL19. H. pylori stimulated DC were also capable of presenting antigen to T cells and secreted Th1 inducing cytokines. Using human gastric tissue we could also show that there is an accumulation of mature DC associated with lymphoid follicles and CD4+ T cells, in the infected gastric mucosa, and also increased levels of CCL19. Further, we have shown that production of the mucosal chemokine CCL28 is increased in H. pylori infections and that there is a correlation between CCL28 and IgA concentration in the gastric tissue of H. pylori infected individuals. Moreover, gastric IgA-secreting cells from H. pylori infected, but not uninfrcted, tissue had a robust migration toward CCL28. Based on our results in this thesis we suggest that mature DC are retained in the gastric mucosa due to H. pylori infection, and that they contribute to sustaining the chronic inflammation. We have also shown that the expression of CCL28 is increased in human H. pylori-induced gastritis and that CCL28 may contribute to effector B-cell recruitment to the gastric mucosa in H. pylori-induced gastritis.
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| 29. |
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| 30. |
- Jakobsson, Hedvig E, et al.
(författare)
-
The composition of the gut microbiota shapes the colon mucus barrier.
- 2015
-
Ingår i: EMBO reports. - : EMBO. - 1469-3178 .- 1469-221X. ; 16, s. 164-177
-
Tidskriftsartikel (refereegranskat)abstract
- Two C57BL/6 mice colonies maintained in two rooms of the same specific pathogen-free (SPF) facility were found to have different gut microbiota and a mucus phenotype that was specific for each colony. The thickness and growth of the colon mucus were similar in the two colonies. However, one colony had mucus that was impenetrable to bacteria or beads the size of bacteria-which is comparable to what we observed in free-living wild mice-whereas the other colony had an inner mucus layer penetrable to bacteria and beads. The different properties of the mucus depended on the microbiota, as they were transmissible by transfer of caecal microbiota to germ-free mice. Mice with an impenetrable mucus layer had increased amounts of Erysipelotrichi, whereas mice with a penetrable mucus layer had higher levels of Proteobacteria and TM7 bacteria in the distal colon mucus. Thus, our study shows that bacteria and their community structure affect mucus barrier properties in ways that can have implications for health and disease. It also highlights that genetically identical animals housed in the same facility can have rather distinct microbiotas and barrier structures.
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| 31. |
- Karlsson, Hasse, 1943, et al.
(författare)
-
High-throughput and high-sensitivity nano-LC/MS and MS/MS for O-glycan profiling.
- 2009
-
Ingår i: Methods in molecular biology (Clifton, N.J.). - Totowa, NJ : Humana Press. - 1064-3745. ; 534, s. 117-31
-
Tidskriftsartikel (refereegranskat)abstract
- Sensitive and fast methods for the profiling of biologically important molecules are highly demanded. Mucins are densely O-glycosylated glycoproteins found at mucosal surfaces and are of great medical interest. Here we describe sensitive methods for the analysis of O-glycans from mucins using gel electrophoresis, and chromatography by nanoLC on graphite columns and structural analysis by electrospray mass spectrometry on a linear trap mass spectrometer.
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| 32. |
- Link, Thomas, et al.
(författare)
-
Bioprocess development for the production of a recombinant MUC1 fusion protein expressed by CHO-K1 cells in protein-free medium
- 2004
-
Ingår i: J Biotechnol. ; 110, s. 51-62
-
Tidskriftsartikel (refereegranskat)abstract
- The mucin MUC1 is a candidate for use in specific immunotherapy against breast cancer, but this requires the large-scale production of a MUC1 antigen. In this study, a bioprocess for the expression of a recombinant MUC1 fusion protein with a cancer associated glycosylation in CHO-K1 cells has been developed. Cells permanently expressing parts of the extracellular portion of MUC1 fused to IgG Fc were directly transferred from adherent growth in serum-containing medium to suspension culture in the protein-free ProCHO4-CDM culture medium. Using the Cellferm-pro® system, optimal culture parameter as pH and pO2 were determined in parallel spinner flask batch cultures. A pH of 6.8–7.0 and a pO2 of 40% of air saturation was found to give best cell growth and productivity of secreted recombinant protein. Specific productivity strongly depended the pO2 and correlated with the online monitored oxygen uptake rate (OUR) of the cells, which indicates a positive influence of the rate of oxidative phosphorylation on productivity. The optimised conditions were applied to continuous perfusion culture which gave very high cell densities and space time yields of the recombinant MUC1 fusion protein, allowing production at gram scale. The product degradation was much lower in supernatants from continuous perfusion culture compared to batch mode. Antibodies reacting with cancer associated MUC1 glycoforms strongly bound to the fusion protein, indicating that the desired glycoforms were obtained and suggesting that the recombinant MUC1 protein could be tested for use in immunotherapy.
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| 33. |
-
Maktordningar och motstånd : forskarperspektiv på #metoo i Sverige
- 2022
-
Samlingsverk (redaktörskap) (refereegranskat)abstract
- Den svenska #metoo-rörelsen samlade under sina första två år (2017–2019) mer än 100 000 deltagare från över 70 olika yrken och samhällsområden. I Maktordningar och motstånd belyser en grupp forskare rörelsen ur olika perspektiv och tecknar en flerdimensionell bild av hur #metoo-aktivismen i Sverige utvecklades i samspelet mellan teknik och kultur, sociala och traditionella medier, och enskilda aktörers initiativ.Genom nedslag i olika miljöer visar forskarna hur ett strukturellt förtryck i form av sexism, sexuella trakasserier och sexuellt våld uttrycks och förklaras. De visar även hur förtrycket normaliseras och förstärks i sammanhang som kännetecknas av gränslösa beteenden, maskulinitetsgörande och en utbredd tystnadskultur. Inte minst viktigt framkommer i studien att sexuella trakasserier handlar om maktutövning. Förtrycket blir särskilt tydligt i branscher där många arbetar under prekära omständigheter och där bristen på utvägar ökar risken för de som vågar säga ifrån. Forskningsresultaten visar också hur olika diskriminerande grunder, som till exempel kön, ålder och anställningsform samverkar.Boken ger en överblick över den svenska #metoo-rörelsens utveckling samt ger en större kunskap om särskilda riskfaktorer. Författarna pekar även ut strategier för att motverka förtryck och möjliggöra förändring.
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| 34. |
- Nilsson, Harriet E., et al.
(författare)
-
Intestinal MUC2 mucin supramolecular topology by packing and release resting on D3 domain assembly.
- 2014
-
Ingår i: Journal of molecular biology. - : Elsevier BV. - 1089-8638 .- 0022-2836. ; 426:14, s. 2567-79
-
Tidskriftsartikel (refereegranskat)abstract
- MUC2 is the major gel-forming mucin of the colon forming a protective gel barrier organized into an inner stratified and an outer loose layer. The MUC2 N-terminus (D1-D2-D'D3 domains) has a dual function in building a net-like structure by disulfide-bonded trimerization and packing the MUC2 polymer into an N-terminal concatenated polygonal platform with the C-termini extending perpendicularly by pH- and calcium-dependent interactions. We studied the N-terminal D'D3 domain by producing three recombinant variants, with or without Myc tag and GFP (green fluorescent protein), and analyzed these by gel filtration, electron microscopy and single particle image processing. The three variants were all trimers when analyzed upon denaturing conditions but eluted as hexamers upon gel filtration under native conditions. Studies by electron microscopy and three-dimensional maps revealed cage-like structures with 2- and 3-fold symmetries. The structure of the MUC2 D3 domain confirms that the MUC2 mucin forms branched net-like structures. This suggests that the MUC2 mucin is stored with two N-terminal concatenated ring platforms turned by 180° against each other, implicating that every second unfolded MUC2 net in mature mucus is turned upside down.
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| 35. |
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| 36. |
- Olofsson, Roger, 1978, et al.
(författare)
-
Isolated hepatic perfusion as a treatment for uveal melanoma liver metastases (the SCANDIUM trial) : study protocol for a randomized controlled trial
- 2014
-
Ingår i: Trials. - : Springer Science and Business Media LLC. - 1745-6215. ; 15, s. 317-
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Uveal melanoma is the most common primary intraocular malignancy in adults. Despite successful control of the primary tumor, metastatic disease will ultimately develop in approximately 50% of patients, with the liver being the most common site for metastases. The median survival for patients with liver metastases is between 6 and 12 months, and no treatment has in randomized trials ever been shown to prolong survival. A previous phase II trial using isolated hepatic perfusion (IHP) has suggested a 14-month increase in overall survival compared with a historic control group consisting of the longest surviving patients in Sweden during the same time period (26 versus 12 months). Methods/Design: This is the protocol for a multicenter phase III trial randomizing patients with isolated liver metastases of uveal melanoma to IHP or best alternative care (BAC). Inclusion criteria include liver metastases (verified by biopsy) and no evidence of extra-hepatic tumor manifestations by positron emission tomography-computed tomography (PET-CT). The primary endpoint is overall survival at 24 months, with secondary endpoints including response rate, progression-free survival, and quality of life. The planned sample size is 78 patients throughout five years. Discussion: Patients with isolated liver metastases of uveal melanoma origin have a short expected survival and no standard treatment option exists. This is the first randomized clinical trial to evaluate IHP as a treatment option with overall survival being the primary endpoint.
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| 37. |
- Olson, Fredrik J., 1975, et al.
(författare)
-
A MUC1 tandem repeat reporter protein produced in CHO-K1 cells has sialylated core 1 O-glycans and becomes more densely glycosylated if coexpressed with polypeptide-GalNAc-T4 transferase
- 2005
-
Ingår i: Glycobiology. - : Oxford University Press (OUP). - 0959-6658 .- 1460-2423. ; 15:2, s. 177-91
-
Tidskriftsartikel (refereegranskat)abstract
- A recombinant mucin O-glycosylation reporter protein, containing 1.7 tandem repeats (TRs) from the transmembrane mucin MUC1, was constructed. The reporter protein, MUC1(1.7TR)-IgG2a, was produced in CHO-K1 cells to study the glycosylation of the MUC1 TR and the in vivo role of polypeptide-GalNAc-T4 glycosyltransferase. N-terminal sequencing of MUC1(1.7TR)-IgG2a showed that all five potential O-glycosylation sites within the TR were used, with an average density of 4.5 glycans per repeat. The least occupied site was Thr in the PDTR motif, where 75% of the molecules were glycosylated, compared to 88-97% at the other sites. This glycan density was confirmed by an alternative liquid chromatography-mass spectrometry (LC-MS) based approach. The O-linked oligosaccharides were released from MUC1(1.7TR)-IgG2a and analyzed by nano-LC-MS and LC-MS/MS. Four oligosaccharides were present, NeuAcalpha2-3Galbeta1-3GalNAcol, NeuAcalpha2-3Galbeta1-3(NeuAcalpha2-6)GalNAcol, Galbeta1-3(NeuAcalpha2-6)GalNAcol, and Galbeta1-3GalNAcol, the two first being most abundant. Coexpression of the human polypeptide-GalNAc-T4 transferase with MUC1(1.7TR)-IgG2a increased the glycan occupancy at Thr in PDTR, Ser in VTSA, and Ser in GSTA, supporting the function of GalNAc-T4 proposed from previous in vitro studies. The expression of GalNAc-T4 with a mutation in the first lectin domain (alpha) had no glycosylation effect on PDTR and GSTA but surprisingly gave a dominant negative effect with a decreased glycosylation to around 50% at the Ser in VTSA. The results show that introduction of glycosyltransferases can specifically alter the sites for O-glycosylation in vivo.
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| 38. |
- Persson, Jonas, et al.
(författare)
-
Molecular evolution of specific human antibody against MUC1 mucin results in improved recognition of the antigen on tumor cells.
- 2009
-
Ingår i: Tumour biology : the journal of the International Society for Oncodevelopmental Biology and Medicine. - : Springer Science and Business Media LLC. - 1423-0380 .- 1010-4283. ; 30:4, s. 221-31
-
Tidskriftsartikel (refereegranskat)abstract
- The MUC1 mucin is differentially expressed and glycosylated in cancer tissue as opposed to healthy tissue. Due to these differences, MUC1 is considered a potential biomarker suitable for cancer diagnosis and therapy. In a previous study, the human MUC1-specific antibody 12ESC-6 was able to bind a sequence variant of the tandem repeat of MUC1 that is not recognized by many other MUC1-specific antibodies. It was also found to bind efficiently to MUC1-carrying cells. We have now used 12ESC-6 as starting point for random mutagenesis to isolate variants with improved ability to bind MUC1 in human tumor tissue. The resulting 12ESC-6 variants were shown to recognize not only the naked MUC1 tandem repeat but even more so glycosylated variants thereof, in particular those carrying the GalNAc (Tn) glycoform. Selected variants of 12ESC-6 demonstrated improved staining of MUC1 on cell lines using flow cytometry and improved staining of the antigen in breast tumor tissue by immunohistochemistry. Molecular evolution and specific fine-tuning thus have the potential to improve the performance of antibody specificities targeting tumor-associated epitopes on MUC1 mucin.
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| 39. |
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| 40. |
- Rughetti, Aurelia, et al.
(författare)
-
Recombinant tumor-associated MUC1 glycoprotein impairs the differentiation and function of dendritic cells
- 2005
-
Ingår i: J Immunol. ; 174:12, s. 7764-7772
-
Tidskriftsartikel (refereegranskat)abstract
- Tumors exploit several strategies to evade immune recognition, including the production of a large number of immunosuppressive factors, which leads to reduced numbers and impaired functions of dendritic cells (DCs) in the vicinity of tumors. We have investigated whether a mucin released by tumor cells could be involved in causing these immunomodulating effects on DCs. We used a recombinant purified form of the MUC1 glycoprotein, an epithelial associated mucin that is overexpressed, aberrantly glycosylated, and shed during cancer transformation. The O-glycosylation profile of the recombinant MUC1 glycoprotein (ST-MUC1) resembled that expressed by epithelial tumors in vivo, consisting of large numbers of sialylated core 1 (sialyl-T, ST) oligosaccharides. When cultured in the presence of ST-MUC1, human monocyte-derived DCs displayed a modified phenotype with decreased expression of costimulatory molecules (CD86, CD40), Ag-presenting molecules (DR and CD1d), and differentiation markers (CD83). In contrast, markers associated with an immature phenotype, CD1a and CD206 (mannose receptor), were increased. This effect was already evident at day 4 of DC culture and was dose dependent. The modified phenotype of DCs corresponded to an altered balance in IL-12/IL-10 cytokine production, with DC expressing an IL-10highIL-12low phenotype after exposure to ST-MUC1. These DCs were defective in their ability to induce immune responses in both allogeneic and autologous settings, as detected in proliferation and ELISPOT assays. The altered DC differentiation and Ag presentation function induced by the soluble sialylated tumor-associated mucin may represent a mechanism by which epithelial tumors can escape immunosurveillance.
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| 41. |
- Sewell, Robert, et al.
(författare)
-
The ST6GalNAc-I sialyltransferase localizes throughout the Golgi and is responsible for the synthesis of the tumor-associated sialyl-Tn O-glycan in humna breast cancer
- 2006
-
Ingår i: J Biol Chem. ; 281:6, s. 3586-3594
-
Tidskriftsartikel (refereegranskat)abstract
- The functional properties of glycoproteins are strongly influenced by their profile of glycosylation, and changes in this profile are seen in malignancy. In mucin-type O-linked glycosylation these changes can result in the production of mucins such as MUC1, carrying shorter sialylated O-glycans, and with different site occupancy. Of the tumor-associated sialylated O-glycans, the disaccharide, sialyl-Tn (sialic acid {alpha}2,6GalNAc), is expressed by 30% of breast carcinomas and is the most tumor-specific. The ST6GalNAc-I glycosyltransferase, which can catalyze the transfer of sialic acid to GalNAc, shows a highly restricted pattern of expression in normal adult tissues, being largely limited to the gastrointestinal tract and absent in mammary gland. In breast carcinomas, however, a complete correlation between the expression of RNA-encoding ST6GalNAc-I and the expression of sialyl-Tn is evident, demonstrating that the expression of sialyl-Tn results from switching on expression of hST6GalNAc-I. Endogenous or exogenous expression of hST6GalNAc-I (but not ST6GalNAc-II) always results in the expression of sialyl-Tn. This ability to override core 1/core 2 pathways of O- linked glycosylation is explained by the localization of ST6GalNAc-I, which is found throughout the Golgi stacks. The development of a Chinese hamster ovary (CHO) cell line expressing MUC1 and ST6GalNAc-I allowed the large scale production of MUC1 carrying 83% sialyl-Tn O-glycans. The presence of ST6GalNAc-I in the CHO cells reduced the number of O-glycosylation sites occupied in MUC1, from an average of 4.3 to 3.8 per tandem repeat. The availability of large quantities of this MUC1 glycoform will allow the evaluation of its efficacy as an immunogen for immunotherapy of MUC1/STn-expressing tumors.
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| 42. |
- Sihlbom, Carina, 1973, et al.
(författare)
-
Localization of O-glycans in MUC1 glycoproteins using electron-capture dissociation fragmentation mass spectrometry.
- 2009
-
Ingår i: Glycobiology. - : Oxford University Press (OUP). - 1460-2423 .- 0959-6658. ; 19:4, s. 375-81
-
Tidskriftsartikel (refereegranskat)abstract
- MUC1 is a mucin glycoprotein containing multiple tandem repeats of 20 amino acids, with five serines and threonines that can be O-glycosylated. Here, we investigated the O-glycosylation site occupancy in MUC1 glycoproteins produced in two mutant CHO cell lines, Lec3.2.8.1 and ldlD. We found that the average site occupancy was higher in MUC1 from Lec3.2.8.1 than from ldlD and that the occupancy increased with the number of tandem repeats in the protein and also depended on the culture conditions used for production. Moreover, we describe the successful use of electron-capture dissociation (ECD) fragmentation, coupled to online liquid chromatography mass spectrometry, to determine the glycosylation of individual sites in recombinant MUC1 proteins with 16 tandem repeats. We analyzed MUC1 tandem repeat peptides with 1-5 GalNAc residues by ECD fragmentation and found that the first site to be glycosylated was either Ser-5 or Thr-6, with the addition of a second GalNAc at Thr-14. For peptides with three GalNAc residues, several different variants of glycopeptides were found, indicating a heterogeneous order of glycosylation at this stage. In contrast, only one variant was found for peptides with four GalNAc residues, where Thr-19 in the PDTR motif was left unglycosylated, indicating that this site is glycosylated last. The results gave novel insight into the order of GalNAc substitution in MUC1 in vivo.
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| 43. |
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| 44. |
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| 45. |
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| 46. |
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| 47. |
- Thomsson, Elisabeth, 1975, et al.
(författare)
-
Recombinant glycoprotein E produced in mammalian cells in large-scale as an antigen for varicella-zoster-virus serology.
- 2011
-
Ingår i: Journal of virological methods. - : Elsevier BV. - 1879-0984 .- 0166-0934. ; 175:1, s. 53-9
-
Tidskriftsartikel (refereegranskat)abstract
- A recombinant glycoprotein E (gE) from varicella-zoster virus (VZV) was generated and produced in Chinese Hamster Ovary (CHO) cells, in the development of a specific antigen for analysis of IgG antibodies to VZV. Several stable gE-secreting clones were established and one clone was adapted to growth in serum-free suspension culture. When the cells were cultured in a perfusion bioreactor, gE was secreted into the medium, from where it could be easily purified. The recombinant gE was then evaluated as a serological antigen in ELISA. When compared to a conventional whole virus antigen, the VZV gE showed similar results in ELISA-based seroprevalence studies of 854 samples derived from blood donors, students, ischemic stroke patients and their controls, including samples with border-line results in previous analyses. Eight samples (0.9%) were discordant, all being IgG-negative by the VZV gE ELISA and positive by the whole virus ELISA. The sensitivity and specificity of the VZV gE ELISA were 99.9% and 100%, respectively, compared to 100% and 88.9% for the VZV whole virus ELISA. The elderly subjects showed similar reactivities to both antigens, while VZV gE gave lower signals in the younger cohorts, suggesting that antibodies to gE may increase with age. It was concluded that the recombinant VZV gE from CHO cells was suitable as a serological antigen for the detection of IgG antibodies specific for VZV.
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| 48. |
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| 49. |
- Thomsson, Kristina A, 1969, et al.
(författare)
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Enhanced Detection of Sialylated and Sulfated Glycans with Negative Ion Mode Nanoliquid Chromatography/Mass Spectrometry at High pH.
- 2010
-
Ingår i: Analytical chemistry. - : American Chemical Society (ACS). - 1520-6882 .- 0003-2700. ; 82:4, s. 1470-1477
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Tidskriftsartikel (refereegranskat)abstract
- Negative ion mode nanoliquid chromatography/mass spectrometry (nano-LC/MS) on porous graphitic carbon columns at pH 11 was studied and compared to capillary LC/MS at pH 8 for the analysis of neutral and acidic glycan alditols. Oligosaccharides were chromatographed with an acetonitrile gradient containing 0.04% ammonium hydroxide and analyzed with a linear ion trap mass spectrometer (LTQ) equipped with a modified nanospray interface. Analysis of acidic N- and O-glycan standards revealed that good quality MS/MS spectra could be obtained when loading 1-3 fmol, a 10-fold increase in sensitivity compared to capillary-LC/MS at pH 8. Analysis of a complex mixture of O-glycans from porcine colonic mucins with nano-LC/MS and MS/MS at high pH revealed 170 oligosaccharides in one analysis, predominantly corresponding to sulfated glycans with up to 11 residues. Analysis of the same sample with capillary-LC/MS showed a lower sensitivity for multiply sulfated glycans. Nano-LC/MS of O-linked oligosaccharides on MUC2 from a human colon biopsy also illustrated that the ionization of oligosaccharides with multiple sialic acid groups was increased compared to those with only one sialic acid residue. Nano-LC/MS at high pH is, thus, a highly sensitive approach for the analysis of acidic oligosaccharides.
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- Wada, Yoshinao, et al.
(författare)
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Comparison of methods for profiling O-glycosylation: Human Proteome Organisation Human Disease Glycomics/Proteome Initiative multi-institutional study of IgA1.
- 2010
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Ingår i: Molecular & cellular proteomics. - 1535-9484. ; 9:4, s. 719-727
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Tidskriftsartikel (refereegranskat)abstract
- The Human Proteome Organisation Human Disease Glycomics/Proteome Initiative recently coordinated a multi-institutional study that evaluated methodologies that are widely used for defining the N-glycan content in glycoproteins. The study convincingly endorsed mass spectrometry as the technique of choice for glycomic profiling in the discovery phase of diagnostic research. The present study reports the extension of the Human Disease Glycomics/Proteome Initiative's activities to an assessment of the methodologies currently used for O-glycan analysis. Three samples of IgA1 isolated from the serum of patients with multiple myeloma were distributed to 15 laboratories worldwide for O-glycomics analysis. A variety of mass spectrometric and chromatographic procedures representative of current methodologies were used. Similar to the previous N-glycan study, the results convincingly confirmed the pre-eminent performance of MS for O-glycan profiling. Two general strategies were found to give the most reliable data, namely direct MS analysis of mixtures of permethylated reduced glycans in the positive ion mode and analysis of native reduced glycans in the negative ion mode using LC-MS approaches. In addition, mass spectrometric methodologies to analyze O-glycopeptides were also successful.
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