umu.sePublications
Change search
Refine search result
1234567 101 - 150 of 1695
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 101.
    Arnqvist, Jennifer
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Biomedical Laboratory Science. Umeå University, Faculty of Medicine, Department of Medical Biosciences, Pathology.
    Optimering av lymfocytfraktionering med AutoMACS Pro för biobankning av hematologiska maligniteter2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 102.
    Arvidsson, Malin
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Infectious Diseases.
    Five-year follow-up after the outbreak of Cryptosporidium hominis in Östersund2018Independent thesis Basic level (professional degree), 20 credits / 30 HE creditsStudent thesis
  • 103. Asghar, Naveed
    et al.
    Lee, Yi-Ping
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Virology. Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS).
    Nilsson, Emma
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Virology. Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS).
    Lindqvist, Richard
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Virology. Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS).
    Melik, Wessam
    Kröger, Andrea
    Överby, Anna K.
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Virology. Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS).
    Johansson, Magnus
    The role of the poly(A) tract in the replication and virulence of tick-borne encephalitis virus2016In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 6, article id 39265Article in journal (Refereed)
    Abstract [en]

    The tick-borne encephalitis virus (TBEV) is a flavivirus transmitted to humans, usually via tick bites. The virus causes tick-borne encephalitis (TBE) in humans, and symptoms range from mild flu-like symptoms to severe and long-lasting sequelae, including permanent brain damage. It has been suggested that within the population of viruses transmitted to the mammalian host, quasispecies with neurotropic properties might become dominant in the host resulting in neurological symptoms. We previously demonstrated the existence of TBEV variants with variable poly(A) tracts within a single blood-fed tick. To characterize the role of the poly(A) tract in TBEV replication and virulence, we generated infectious clones of Toro-2003 with the wild-type (A)(3)C(A)(6) sequence (Toro-6A) or with a modified (A)(3)C(A)(38) sequence (Toro-38A). Toro-38A replicated poorly compared to Toro-6A in cell culture, but Toro-38A was more virulent than Toro-6A in a mouse model of TBE. Next-generation sequencing of TBEV genomes after passaging in cell culture and/or mouse brain revealed mutations in specific genomic regions and the presence of quasispecies that might contribute to the observed differences in virulence. These data suggest a role for quasispecies development within the poly(A) tract as a virulence determinant for TBEV in mice.

  • 104. Asghar, Naveed
    et al.
    Lindblom, Pontus
    Melik, Wessam
    Lindqvist, Richard
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Virology.
    Haglund, Mats
    Forsberg, Pia
    Överby, Anna K.
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Virology.
    Andreassen, Åshild
    Lindgren, Per-Eric
    Johansson, Magnus
    Tick-borne encephalitis virus sequenced directly from questing and blood-feeding ticks reveals quasispecies variance2014In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 9, no 7, p. e103264-Article in journal (Refereed)
    Abstract [en]

    The increased distribution of the tick-borne encephalitis virus (TBEV) in Scandinavia highlights the importance of characterizing novel sequences within the natural foci. In this study, two TBEV strains: the Norwegian Mandal 2009 (questing nymphs pool) and the Swedish Saringe 2009 (blood-fed nymph) were sequenced and phylogenetically characterized. Interestingly, the sequence of Mandal 2009 revealed the shorter form of the TBEV genome, similar to the highly virulent Hypr strain, within the 3' non-coding region (3'NCR). A different genomic structure was found in the 3'NCR of Saringe 2009, as in-depth analysis demonstrated TBEV variants with different lengths within the poly(A) tract. This shows that TBEV quasispecies exists in nature and indicates a putative shift in the quasispecies pool when the virus switches between invertebrate and vertebrate environments. This prompted us to further sequence and analyze the 3'NCRs of additional Scandinavian TBEV strains and control strains, Hypr and Neudoerfl. Toro 2003 and Habo 2011 contained mainly a short (A) 3C(A)6 poly(A) tract. A similar pattern was observed for the human TBEV isolates 1993/783 and 1991/4944; however, one clone of 1991/4944 contained an (A) 3C(A)11 poly(A) sequence, demonstrating that quasispecies with longer poly(A) could be present in human isolates. Neudoerfl has previously been reported to contain a poly(A) region, but to our surprise the resequenced genome contained two major quasispecies variants, both lacking the poly(A) tract. We speculate that the observed differences are important factors for the understanding of virulence, spread, and control of the TBEV.

  • 105.
    Aspelin, Jesper
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Biomedical Laboratory Science.
    Anrikning med Illumina Nextera XT sekvenseringsbibliotek2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
  • 106.
    Augustsson Sjögren, Daniel
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Biomedical Laboratory Science.
    Characterisation of aptamers selected for binding to Yersinia pestis virulence protein LcrV2011Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 107. Avsic-Zupanc, T
    et al.
    Petrovec, M
    Furlan, P
    Kaps, R
    Elgh, Fredrik
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Virology.
    Lundkvist, A
    Hemorrhagic fever with renal syndrome in the Dolenjska region of Slovenia--a 10-year survey.1999In: Clinical Infectious Diseases, ISSN 1058-4838, E-ISSN 1537-6591, Vol. 28, no 4, p. 860-5Article in journal (Refereed)
    Abstract [en]

    This report describes the first investigation of clinical findings for a larger series of patients with hemorrhagic fever with renal syndrome (HFRS) who were infected with Dobrava virus. From 1985 to 1995, 38 patients with serologically confirmed HFRS were hospitalized at the regional hospital in Novo mesto in the Dolenjska region of Slovenia. On the basis of results of serological examination, 24 patients had Dobrava virus infection, and 14 patients had Puumala virus infection. Complete clinical data were available for 31 patients. Eleven patients underwent hemodialysis for treatment of acute oliguric or anuric renal failure. Four patients, all infected by Dobrava virus, had signs of shock and severe bleeding. Three severely ill Dobrava virus-infected patients died of hemorrhagic complications. We have demonstrated that Dobrava and Puumala viruses coexist in a single region of endemicity and are capable of causing HFRS with significant differences in severity.

  • 108. Axelsson-Olsson, Diana
    et al.
    Waldenström, Jonas
    Broman, Tina
    Umeå University, Faculty of Medicine, Molecular Biology (Faculty of Medicine). Umeå University, Faculty of Medicine, Clinical Microbiology, Infectious Diseases.
    Olsen, Björn
    Umeå University, Faculty of Medicine, Clinical Microbiology, Infectious Diseases.
    Holmberg, Martin
    Protozoan Acanthamoeba polyphaga as a potential reservoir for Campylobacter jejuni.2005In: Applied and Environmental Microbiology, ISSN 0099-2240, Vol. 71, no 2, p. 987-92Article in journal (Refereed)
    Abstract [en]

    We showed by a laboratory experiment that four different Campylobacter jejuni strains are able to infect the protozoan Acanthamoeba polyphaga. C. jejuni cells survived for longer periods when cocultured with amoebae than when grown in culture alone. The infecting C. jejuni cells aggregated in amoebic vacuoles, in which they were seen to be actively moving. Furthermore, a resuscitation of bacterial cultures that were previously negative in culturability tests was observed after reinoculation into fresh amoeba cultures. After spontaneous rupture of the amoebae, C. jejuni could be detected by microscopy and culturability tests. Our results indicate that amoebae may serve as a nonvertebrate reservoir for C. jejuni in the environment.

  • 109.
    Backlund, Christoffer
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Clinical Bacteriology. Umeå University, Faculty of Medicine, Department of Clinical Sciences, Otorhinolaryngology.
    Prevalence of Fusobacterium necrophorum and emm-types of Group A Streptococci in tonsillitis in Umeå2018Independent thesis Basic level (professional degree), 20 credits / 30 HE creditsStudent thesis
  • 110.
    Backman, Ida
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology.
    Elgh, Fredrik
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology.
    Infectious microorganisms in the vascular wall of the aorta in patients with abdominal aortic aneurysm2013Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
  • 111. Baggen, Jim
    et al.
    Hurdiss, Daniel L.
    Zocher, Georg
    Mistry, Nitesh
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Virology.
    Roberts, Richard W.
    Slager, Jasper J.
    Guo, Hongbo
    van Vliet, Arno L. W.
    Wahedi, Maryam
    Benschop, Kimberley
    Duizer, Erwin
    de Haan, Cornelis A. M.
    de Vries, Erik
    Casasnovas, José M.
    de Groot, Raoul J.
    Arnberg, Niklas
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Virology.
    Stehle, Thilo
    Ranson, Neil A.
    Thibaut, Hendrik Jan
    van Kuppeveld, Frank J. M.
    Role of enhanced receptor engagement in the evolution of a pandemic acute hemorrhagic conjunctivitis virus2018In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 115, no 2, p. 397-402Article in journal (Refereed)
    Abstract [en]

    Acute hemorrhagic conjunctivitis (AHC) is a painful, contagious eye disease, with millions of cases in the last decades. Coxsackievirus A24 (CV-A24) was not originally associated with human disease, but in 1970 a pathogenic "variant" (CV-A24v) emerged, which is now the main cause of AHC. Initially, this variant circulated only in Southeast Asia, but it later spread worldwide, accounting for numerous AHC outbreaks and two pandemics. While both CV-A24 variant and nonvariant strains still circulate in humans, only variant strains cause AHC for reasons that are yet unknown. Since receptors are important determinants of viral tropism, we set out to map the CV-A24 receptor repertoire and establish whether changes in receptor preference have led to the increased pathogenicity and rapid spread of CV-A24v. Here, we identify ICAM-1 as an essential receptor for both AHC-causing and non-AHC strains. We provide a high-resolution cryo-EM structure of a virus-ICAM-1 complex, which revealed critical ICAM-1-binding residues. These data could help identify a possible conserved mode of receptor engagement among ICAM-1-binding enteroviruses and rhinoviruses. Moreover, we identify a single capsid substitution that has been adopted by all pandemic CV-A24v strains and we reveal that this adaptation enhances the capacity of CV-A24v to bind sialic acid. Our data elucidate the CV-A24v receptor repertoire and point to a role of enhanced receptor engagement in the adaptation to the eye, possibly enabling pandemic spread.

  • 112. Baharom, Faezzah
    et al.
    Rankin, Gregory
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Scholz, Saskia
    Pourazar, Jamshid
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Ahlm, Clas
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Infectious Diseases.
    Blomberg, Anders
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Smed-Sörensen, Anna
    Human lung dendritic cells: spatial distribution and phenotypic identification in endobronchial biopsies using immunohistochemistry and flow cytometry2017In: Jove-journal pf visualized experiments, ISSN 1940-087X, no 119, article id e55222Article in journal (Refereed)
    Abstract [en]

    The lungs are constantly exposed to the external environment, which in addition to harmless particles, also contains pathogens, allergens, and toxins. In order to maintain tolerance or to induce an immune response, the immune system must appropriately handle inhaled antigens. Lung dendritic cells (DCs) are essential in maintaining a delicate balance to initiate immunity when required without causing collateral damage to the lungs due to an exaggerated inflammatory response. While there is a detailed understanding of the phenotype and function of immune cells such as DCs in human blood, the knowledge of these cells in less accessible tissues, such as the lungs, is much more limited, since studies of human lung tissue samples, especially from healthy individuals, are scarce. This work presents a strategy to generate detailed spatial and phenotypic characterization of lung tissue resident DCs in healthy humans that undergo a bronchoscopy for the sampling of endobronchial biopsies. Several small biopsies can be collected from each individual and can be subsequently embedded for ultrafine sectioning or enzymatically digested for advanced flow cytometric analysis. The outlined protocols have been optimized to yield maximum information from small tissue samples that, under steady-state conditions, contain only a low frequency of DCs. While the present work focuses on DCs, the methods described can directly be expanded to include other (immune) cells of interest found in mucosal lung tissue. Furthermore, the protocols are also directly applicable to samples obtained from patients suffering from pulmonary diseases where bronchoscopy is part of establishing the diagnosis, such as chronic obstructive pulmonary disease (COPD), sarcoidosis, or lung cancer.

  • 113. Baharom, Faezzah
    et al.
    Thomas, Saskia
    Rankin, Gregory
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Lepzien, Rico
    Pourazar, Jamshid
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Behndig, Annelie F.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Ahlm, Clas
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Infectious Diseases.
    Blomberg, Anders
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Smed-Sorensen, Anna
    Dendritic Cells and Monocytes with Distinct Inflammatory Responses Reside in Lung Mucosa of Healthy Humans2016In: Journal of Immunology, ISSN 0022-1767, E-ISSN 1550-6606, Vol. 196, no 11, p. 4498-4509Article in journal (Refereed)
    Abstract [en]

    Every breath we take contains potentially harmful pathogens or allergens. Dendritic cells (DCs), monocytes, and macrophages are essential in maintaining a delicate balance of initiating immunity without causing collateral damage to the lungs because of an exaggerated inflammatory response. To document the diversity of lung mononuclear phagocytes at steady-state, we performed bronchoscopies on 20 healthy subjects, sampling the proximal and distal airways (bronchial wash and bronchoalveolar lavage, respectively), as well as mucosal tissue (endobronchial biopsies). In addition to a substantial population of alveolar macrophages, we identified subpopulations of monocytes, myeloid DCs (MDCs), and plasmacytoid DCs in the lung mucosa. Intermediate monocytes and MDCs were highly frequent in the airways compared with peripheral blood. Strikingly, the density of mononuclear phagocytes increased upon descending the airways. Monocytes from blood and airways produced 10-fold more proinflammatory cytokines than MDCs upon ex vivo stimulation. However, airway monocytes were less inflammatory than blood monocytes, suggesting a more tolerant nature. The findings of this study establish how to identify human lung mononuclear phagocytes and how they function in normal conditions, so that dysregulations in patients with respiratory diseases can be detected to elucidate their contribution to immunity or pathogenesis.

  • 114.
    Bailey, Leslie
    et al.
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine).
    Muschiol, Sandra
    Engström, Patrik
    Nordström, Peter
    Henriques-Normark, Birgitta
    Waldenström, Anders
    Gylfe, Åsa
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology. Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Clinical Bacteriology.
    Elofsson, Mikael
    Wolf-Watz, Hans
    Bergström, Sven
    Small molecule inhibitors reveal a role for the Chlamydia type III secretion system in iron acquisitionManuscript (Other academic)
  • 115.
    Bally, Marta
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology. Umeå University, Faculty of Medicine, Wallenberg Centre for Molecular Medicine at Umeå University (WCMM).
    Regulating the dynamic interactions between herpes simplex viruses and cell -surface glycosaminoglycans2019In: European Biophysics Journal, ISSN 0175-7571, E-ISSN 1432-1017, Vol. 48, p. S41-S41Article in journal (Other academic)
    Abstract [en]

    Virus entry is a complex dynamic multistep process requiring a series of fine-tuned events mediating virus diffusion through the glycocalyx, its attachment to the cell membrane and lateral diffusion to the point of entry. A number of enveloped viruses, including herpes simplex viruses (HSV) attach to susceptible host cells via interaction between their glycoproteins and cell-surface glycosaminoglycans (GAGs). In our work, we study the molecular and physical mechanisms modulating HSV binding, diffusion and release from cell-surface glycosaminoglycans. Using single virus tracking in combination with either in vitro minimal models of the cell surface or live cell microscopy, we gain insights into the modulatory function of protein glycosylation (the presence of mucin-like regions on viral glycoproteins) and interrogate the role of GAG sulfation in the process. We show that mucin-like regions found on the glycoproteins of HSV-1 and HSV-2 play an important role in modulating the interaction, an observation further supported by cell experiments. We further show that the diffusion of virions on the surface depends on the type of GAGs and their degree of sulfation. Taken together, our research contributes to a better understanding of the mechanisms underlying the interaction between a virus and the surface of its host. Such insights will without doubt facilitate the design of more efficient antiviral drugs or vaccines.

  • 116.
    Banday, Viqar
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Immunology/Immunchemistry.
    Metab-Immune analysis of the non-obese diabetic mouse2016Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Type 1A diabetes mellitus or T1D is a chronic disease characterized by T cell mediated destruction of the insulin producing β cells in the islets of Langerhans. The classical symptoms include high glucose levels in urine and blood, polyuria, and polydipsia. Complications associated with T1D include blindness, amputations, and end-stage renal disease, and premature death. The non-obese diabetic (NOD) mouse, first described in 1980, is widely used as a model organism for T1D. T1D disease in the NOD mouse shares a number of similarities to human T1D including dependence on genetic and environmental factors. More than 30 disease associated gene regions or loci (termed insulin dependent diabetes, or Idd, loci) have been associated with T1D development in NOD. For some of these Idds, the corresponding region in human has been linked to the development of T1D in human.

    T1D, both in humans and mice, is recognized as a T cell mediated disease. However, many studies have shown the importance of both the metabolome and the immune system in the pathogenesis of the disease. Appearance of autoantibodies in the serum of patients is the first sign of pathogenesis. However, molecular and cellular events precede the immune attack on the β-cell immunity. It has been shown that patients who developed T1D have an altered metabolome prior to the appearance of autoantibodies. Although much is known about the pathogenesis of T1D, the contribution of the environment/immune factors triggering the disease is still to be revealed. 

    In the present study both metabolic and immune deviations observed in the NOD mouse was analyzed. Serum metabolome analysis of the NOD mouse revealed striking resemblance to the human metabolic profile, with many metabolites in the TCA cycle significantly different from the non-diabetic control B6 mice. In addition, an increased level of glutamic acid was of the most distinguishing metabolite. A detailed bioinformatics analysis revealed various genes/enzymes to be present in the Idd regions. Compared to B6 mice, many of the genes correlated to the metabolic pathways, showed single nucleotide polymorphism (SNP), which can eventually affect the functionality of the protein. A genetic analysis of the increased glutamic acid revealed several Idd regions to be involved in this phenotype. The regions mapped in the genetic analysis harbor important enzymes and transporters related to glutamic acid. In-vitro islet culture with glutamic acid led to increased beta cell death indicating a toxic role of glutamic acid specifically towards insulin producing beta cells.

    In the analysis of the immune system, B cells from NOD mice, which are known to express high levels of TACI, were stimulated with APRIL, a TACI ligand. This resulted in enhanced plasma cell differentiation accompanied with increased class switching and IgG production. NOD mice have previously been shown to react vigorously to T-dependent antigens upon immunization. In this study we confirmed this as NOD mice showed an enhanced and prolonged immune response to hen egg lysozyme. Thus, serum IgG levels were significantly increased in the NOD mice and were predominantly of the IgG1 subtype. Immunofluorescence analysis revealed increased number of germinal centers in the NOD mice. Transfer of purified B and T cells from NOD to an immune deficient mouse could reproduce the original phenotype as seen in the NOD mice.    

    Collectively, this thesis has analyzed the metabolomics and immune deviations observed in the NOD mice.

  • 117.
    Banday, Viqar Showkat
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Immunology/Immunchemistry.
    Lejon, Kristina
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Immunology/Immunchemistry.
    Elevated Systemic Glutamic Acid Level in the Non-Obese Diabetic Mouse is Idd Linked and Induces Beta Cell Apoptosis2017In: Immunology, ISSN 0019-2805, E-ISSN 1365-2567, Vol. 150, no 2, p. 162-171Article in journal (Refereed)
    Abstract [en]

    Although type 1 diabetes (T1D) is a T-cell-mediated disease in the effector stage, the mechanism behind the initial beta cell assault is less understood. Metabolomic differences, including elevated levels of glutamic acid, have been observed in patients with T1D before disease onset, as well as in pre-diabetic non-obese diabetic (NOD) mice. Increased levels of glutamic acid damage both neurons and beta cells, implying that this could contribute to the initial events of T1D pathogenesis. We investigated the underlying genetic factors and consequences of the increased levels of glutamic acid in NOD mice. Serum glutamic acid levels from a (NODxB6) F-2 cohort (n = 182) were measured. By genome-wide and Idd region targeted microsatellite mapping, genetic association was detected for six regions including Idd2, Idd4 and Idd22. In silico analysis of potential enzymes and transporters located in and around the mapped regions that are involved in glutamic acid metabolism consisted of alanine aminotransferase, glutamic-oxaloacetic transaminase, aldehyde dehydrogenase 18 family, alutamyl-prolyl-tRNA synthetase, glutamic acid transporters GLAST and EAAC1. Increased EAAC1 protein expression was observed in lysates from livers of NOD mice compared with B6 mice. Functional consequence of the elevated glutamic acid level in NOD mice was tested by culturing NOD. Rag2(-/-) Langerhans' islets with glutamic acid. Induction of apoptosis of the islets was detected upon glutamic acid challenge using TUNEL assay. Our results support the notion that a dysregulated metabolome could contribute to the initiation of T1D. We suggest that targeting of the increased glutamic acid in pre-diabetic patients could be used as a potential therapy.

  • 118.
    Banday, Viqar Showkat
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Immunology/Immunchemistry.
    Thyagarajan, Radha
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Immunology/Immunchemistry.
    Lejon, Kristina
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Immunology/Immunchemistry.
    B cell intrinsic defects lead to enhanced immune response in the NOD miceManuscript (preprint) (Other academic)
  • 119.
    Banday, Viqar Showkat
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Immunology/Immunchemistry.
    Thyagarajan, Radha
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Immunology/Immunchemistry.
    Lejon, Kristina
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Immunology/Immunchemistry.
    Contribution of both B cell intrinsic alterations as well as non-hematopoietic derived factors in the enhanced immune response of the NOD mouse2017In: Scandinavian Journal of Immunology, ISSN 0300-9475, E-ISSN 1365-3083, Vol. 86, no 4, p. 252-252Article in journal (Other academic)
  • 120.
    Banday, Viqar Showkat
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Immunology/Immunchemistry.
    Thyagarajan, Radha
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Immunology/Immunchemistry.
    Lejon, Kristina
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Immunology/Immunchemistry.
    Contribution of both B-cell intrinsic alterations as well as non-hematopoietic-derived factors in the enhanced immune response of the NOD mouse2017In: Autoimmunity, ISSN 0891-6934, E-ISSN 1607-842X, Vol. 50, no 6, p. 363-369Article in journal (Refereed)
    Abstract [en]

    The underlying cellular and molecular mechanism for the development of Type 1 diabetes is still to be fully revealed. We have previously demonstrated that the NOD mouse, a model for Type 1 diabetes, display a prolonged and enhanced immune response to both self and non-self-antigens. The molecular explanation for this defect however, has not been determined. In this study we immunized NOD and C57BL/6 (B6) with the conventional antigen i.e. hen egg lysozyme (HEL) and analyzed B cell activation, germinal center reaction and antibody clearance. Corroborating our previous observations NOD mice responded robustly to a single immunization of HEL. Immunofluorescence analysis of the spleen revealed an increased number of germinal centers in unimmunized NOD compared to B6. However, post immunization germinal center numbers were similar in NOD and B6. NOD mice showed lower response to BCR stimulation with anti-IgM, in particular at lower concentrations of anti-IgM. Antibody clearance in vivo did not differ between the strains. To determine the cell type that is responsible for the prolonged and enhance immune response, we reconstituted NOD-RAGs with cells from primed donors in different combinations. NOD B cells were required to reproduce the phenotype; however the non-lymphoid compartment of NOD origin also played a role. Based on our results we propose that preexisting GCs in the NOD promote the robust response and alteration in the BCR signaling could promote survival of stimulated cells. Overall, this mechanism could in turn also contribute to the activation and maintenance of autoreactive B cells in the NOD mouse.

  • 121.
    Banday, Viqar Showkat
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Immunology/Immunchemistry.
    Thyagarajan, Radha
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Immunology/Immunchemistry.
    Sundström, Mia
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Immunology/Immunchemistry.
    Lejon, Kristina
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Immunology/Immunchemistry.
    Increased expression of TACI on NOD B cells results in germinal centre reaction anomalies, enhanced plasma cell differentiation and immunoglobulin production2016In: Immunology, ISSN 0019-2805, E-ISSN 1365-2567, Vol. 149, no 3, p. 297-305Article in journal (Refereed)
    Abstract [en]

    B cells have an important pathogenic role in the development of type 1 diabetes in the non-obese diabetic (NOD) mouse. We have previously reported that NOD mice display an increased percentage of TACIhigh-expressing B cells compared with C57BL/6 mice and this trait is linked to chromosomes 1 and 8. In this paper the genetic association of the transmembrane activator, calcium modulator and cyclophilin ligand interactor (TACI) trait was confirmed using double congenic NOD.B6C1/Idd22 mice. TACI ligation by a proliferation-inducing ligand (APRIL) has been shown to influence plasma cell differentiation, immunoglobulin production and isotype switch. Hence, the functional consequence of the up-regulation of TACI on NOD B cells was analysed both in vitro and in vivo. NOD B cells stimulated with APRIL showed an enhanced plasma cell differentiation and class switch to IgG and IgA compared with B cells from C57BL/6 mice. Moreover, flow cytometry analyses revealed that germinal centre B cells in NOD failed to down-regulate TACI. Availability of the TACI ligand B-cell activating factor (BAFF) has been shown to be a limiting factor in the germinal centre reaction. In line with this, upon immunization with 4-hydroxy-3-nitrophenylacetyl hapten-conjugated hen egg lysozyme, NOD mice produced higher titres of low-affinity antibodies compared with C57BL/6 mice. This observation was supported by the detection of increased levels of BAFF in NOD germinal centres after immunization compared with C57BL/6 by immunofluorescence. Our results support the hypothesis that increased TACI expression on NOD B cells contributes to the pathogenesis of type 1 diabetes in the NOD mouse.

  • 122. Bao, Xiaofeng
    et al.
    Gylfe, Åsa
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Clinical Bacteriology.
    Sturdevant, Gail L.
    Gong, Zheng
    Xu, Shuang
    Caldwell, Harlan D.
    Elofsson, Mikael
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Fan, Huizhou
    Benzylidene acylhydrazides inhibit chlamydial growth in a type III secretion- and iron chelation-independent manner2014In: Journal of Bacteriology, ISSN 0021-9193, E-ISSN 1098-5530, Vol. 196, no 16, p. 2989-3001Article in journal (Refereed)
    Abstract [en]

    Chlamydiae are widespread Gram-negative pathogens of humans and animals. Salicylidene acylhydrazides, developed as inhibitors of type III secretion system (T3SS) in Yersinia spp., have an inhibitory effect on chlamydial infection. However, these inhibitors also have the capacity to chelate iron, and it is possible that their antichlamydial effects are caused by iron starvation. Therefore, we have explored the modification of salicylidene acylhydrazides with the goal to uncouple the antichlamydial effect from iron starvation. We discovered that benzylidene acylhydrazides, which cannot chelate iron, inhibit chlamydial growth. Biochemical and genetic analyses suggest that the derivative compounds inhibit chlamydiae through a T3SS-independent mechanism. Four single nucleotide polymorphisms were identified in a Chlamydia muridarum variant resistant to benzylidene acylhydrazides, but it may be necessary to segregate the mutations to differentiate their roles in the resistance phenotype. Benzylidene acylhydrazides are well tolerated by host cells and probiotic vaginal Lactobacillus species and are therefore of potential therapeutic value.

  • 123. Baptista, Marisa A. P.
    et al.
    Keszei, Marton
    Oliveira, Mariana
    Sunahara, Karen K. S.
    Andersson, John
    Dahlberg, Carin I. M.
    Worth, Austen J.
    Lieden, Agne
    Kuo, I-Chun
    Wallin, Robert P. A.
    Snapper, Scott B.
    Eidsmo, Liv
    Scheynius, Annika
    Karlsson, Mikael C. I.
    Bouma, Gerben
    Burns, Siobhan O.
    Forsell, Mattias N. E.
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Immunology/Immunchemistry.
    Thrasher, Adrian J.
    Nylén, Susanne
    Westerberg, Lisa S.
    Deletion of Wiskott-Aldrich syndrome protein triggers Rac2 activity and increased cross-presentation by dendritic cells2016In: Nature Communications, ISSN 2041-1723, E-ISSN 2041-1723, Vol. 7, article id 12175Article in journal (Refereed)
    Abstract [en]

    Wiskott-Aldrich syndrome (WAS) is caused by loss-of-function mutations in the WASp gene. Decreased cellular responses in WASp-deficient cells have been interpreted to mean that WASp directly regulates these responses in WASp-sufficient cells. Here, we identify an exception to this concept and show that WASp-deficient dendritic cells have increased activation of Rac2 that support cross-presentation to CD8(+) T cells. Using two different skin pathology models, WASp-deficient mice show an accumulation of dendritic cells in the skin and increased expansion of IFN gamma-producing CD8(+) T cells in the draining lymph node and spleen. Specific deletion of WASp in dendritic cells leads to marked expansion of CD8(+) T cells at the expense of CD4(+) T cells. WASp-deficient dendritic cells induce increased cross-presentation to CD8(+) T cells by activating Rac2 that maintains a near neutral pH of phagosomes. Our data reveals an intricate balance between activation of WASp and Rac2 signalling pathways in dendritic cells.

  • 124.
    Baranov, Vladimir
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Clinical Immunology.
    Hammarström, Sten
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Immunology/Immunchemistry.
    Carcinoembryonic antigen (CEA) and CEA-related cell adhesion molecule 1 (CEACAM1), apically expressed on human colonic M cells, are potential receptors for microbial adhesion.2004In: Histochemistry and Cell Biology, ISSN 0948-6143, E-ISSN 1432-119X, Vol. 121, no 2, p. 83-9Article in journal (Refereed)
    Abstract [en]

    In the human gut mucosa, specialized M cells deliver intact foreign macromolecules and commensal bacteria from the lumen to organized mucosal lymphoid tissues triggering immune responses. M cells are also major sites of adhesion and invasion for enteric pathogens. The molecular features of M cell apical surfaces that promote microbial normal attachment are still largely unknown. We have demonstrated previously that in the human colonic epithelium, carcinoembryonic antigen (CEA) and CEA-related cell adhesion molecule 1 (CEACAM1) are integral components of the apical glycocalyx which participate in epithelial-microbial interactions. In this study, based on the reactivity of specific monoclonal antibodies and on immunoelectron microscopy, we show that M cells of human colonic solitary lymphoid follicles express CEA and CEACAM1 on the apical surface. Recently these highly glycosylated molecules have been characterized as protein receptors for different bacteria. This leads us to propose a role for CEA and CEACAM1 in the adherence of enteric bacteria to the apical membrane of colonic M cells. We also hypothesize that, unlike colonic enterocytes, M cells lack the defense mechanism that eliminates CEA and CEACAM1 upon microbial binding and which is based on vesiculation of microvillus plasma membrane.

  • 125.
    Baranov, Vladimir
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Clinical Immunology. Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Immunology/Immunchemistry.
    Nagaeva, Olga
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Clinical Immunology.
    Hammarström, Sten
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Immunology/Immunchemistry.
    Mincheva-Nilsson, Lucia
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Clinical Immunology.
    Lipids are a constitutive component of cytolytic granules.2000In: Histochemistry and Cell Biology, ISSN 0948-6143, E-ISSN 1432-119X, Vol. 114, no 2, p. 167-71Article in journal (Refereed)
    Abstract [en]

    Cytolytic granules are specific organelles of activated cytotoxic lymphocytes mediating storage and regulated excretion of lytic molecules for killing of target cells. A variety of the other granule components may also participate in granule-mediated cytotoxicity. In this study, the subcellular localization of lipids in the granules of human decidual CD56+ natural killer-like cells was determined by staining with malachite green aldehyde and imidazole-buffered osmium tetroxide. Lipids were shown, for the first time, to be a constitutive component of cytolytic granules. Lipids formed an additional structural microdomain, located between the granule-limiting membrane and the granule core. Images of the granules on serial sections suggested that intragranular lipids wrap the core. We speculate that granule lipids participate in packing of lytic molecules inside the granules, in autocrine signaling ending granule secretion, and in the killing process.

  • 126. Baranov, Vladimir
    et al.
    Yeung, Moorix Mo-Wai
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Immunology/Immunchemistry.
    Hammarström, Sten
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Immunology/Immunchemistry.
    Expression of carcinoembryonic antigen and nonspecific cross-reacting 50-kDa antigen in human normal and cancerous colon mucosa: comparative ultrastructural study with monoclonal antibodies1994In: Cancer Research, ISSN 0008-5472, E-ISSN 1538-7445, Vol. 54, no 12, p. 3305-3314Article in journal (Refereed)
    Abstract [en]

    The precise localization of carcinoembryonic antigen (CEA) and non-specific cross-reacting 50-kDa antigen (NCA 50) in normal colon mucosa and colon adenocarcinoma was investigated by using an indirect immunoperoxidase electron microscopic technique with specific monoclonal antibodies. In normal adult colon both antigens were localized to microvesicles and filaments of the "fuzzy coat" on the apical surface of the epithelial cells. In addition, NCA 50 was found in the narrow spaces between adjoining microvilli. Mature columnar cells at the free luminal surface contained most of the antigen positive material. CEA and NCA 50 were also detected as intracellular components of goblet cells. In multilayered tumor glands, the cell surface expression of the antigens was dependent on the position of the tumor cell in the gland. The neoplastic cells showed either a predominant apical labeling or a positive staining of almost the entire cell surface. Some of the neoplastic cells contained CEA in so-called "intracellular lumina." In contrast to normal colon epithelial cells most tumor cells synthesized NCA 50 actively. In normal colonic mucosa, unlike in cancerous tissue, CEA and NCA 50 appear to be released via vesicles formed from the microvillous membrane of mature columnar cells. These results are consistent with the hypothesis that CEA and NCA play a role in the nonspecific defense against microorganisms in the large intestine.

  • 127.
    Baroshki, Rojan
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Biomedical Laboratory Science.
    Mykofenolsyra och AUC-beräkning för organtransplanterade patienter2015Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
  • 128. Barrera, Daniel Iván
    et al.
    Matheus, Luisa Marina
    Stigbrand, Torgny
    Umeå University, Faculty of Medicine, Clinical Microbiology. Umeå University, Faculty of Medicine, Clinical Microbiology, Immunology/Immunchemistry.
    Arbeláez, Luis Fernando
    Proteolytic hydrolysis and purification of the LRP/alfa-2-macroglobulin receptor domain from alpha-macroglobulins.2007In: Protein Expression and Purification, ISSN 1046-5928, E-ISSN 1096-0279, Vol. 53, no 1, p. 112-8Article in journal (Refereed)
    Abstract [en]

    A new, easier and efficient purification method, using Sephacryl and DEAE-Sephacel, of the C-terminal fragment of two alpha-macroglobulins, alpha(2)-M and PZP, is presented. Two larger peptides were identified for each protein as the C-terminal fragment, with molecular weights of approximately 30 kDa and the N-terminal sequences were determined to be SSTQDTV for alpha(2)-M and VALHLS for PZP. The smaller peptides with molecular weights of 18 kDa correspond to a shorter C-terminal sequence of these proteins, and they were determined to be EEFPFA for alpha(2)-M and ALKVQTV for PZP, with no interfering sequences detected. The results confirmed the discriminatory capacity of the purification procedure and the purity of the fragments. This new methodology facilitates biological studies of alpha-macroglobulins, and will enable elucidation of the role the C-terminal region may exert to eliminate alpha-macroglobulin-proteinases complexes from the circulation by the LRP/receptor.

  • 129. Bas, A
    et al.
    Forsberg, G
    Hammarström, S
    Umeå University, Faculty of Medicine, Clinical Microbiology. Umeå University, Faculty of Medicine, Clinical Microbiology, Immunology/Immunchemistry.
    Hammarström, M-L
    Umeå University, Faculty of Medicine, Clinical Microbiology. Umeå University, Faculty of Medicine, Clinical Microbiology, Immunology/Immunchemistry.
    Utility of the housekeeping genes 18S rRNA, beta-actin and glyceraldehyde-3-phosphate-dehydrogenase for normalization in real-time quantitative reverse transcriptase-polymerase chain reaction analysis of gene expression in human T lymphocytes.2004In: Scandinavian Journal of Immunology, ISSN 0300-9475, E-ISSN 1365-3083, Vol. 59, no 6, p. 566-73Article in journal (Refereed)
    Abstract [en]

    The accuracy of 18S rRNA, beta-actin mRNA and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) mRNA as indicators of cell number when used for normalization in gene expression analysis of T lymphocytes at different activation stages was investigated. Quantitative real-time reverse transcriptase-polymerase chain reaction was used to determine the expression level of 18S rRNA, beta-actin mRNA, GAPDH mRNA and mRNA for six cytokines in carefully counted samples of resting human peripheral blood mononuclear cells (PBMCs), intestinal lymphocytes and PBMCs subjected to polyclonal T-cell activation. The 18S rRNA level in activated and resting PBMCs and intestinal lymphocytes was essentially the same, while the levels of beta-actin and GAPDH mRNAs fluctuated markedly upon activation. When isolated gammadeltaTCR(+), CD4(+) and CD8(+) subpopulations were studied, 18S rRNA levels remained unchanged after 21 h of activation but increased slightly after 96 h. In contrast, there was a 30-70-fold increase of GAPDH mRNA/cell in these cell populations upon activation. Cytokine analysis revealed that only normalization to 18S rRNA gave a result that satisfactorily reflected their mRNA expression levels per cell. In conclusion, 18S rRNA was the most stable housekeeping gene and hence superior for normalization in comparative analyses of mRNA expression levels in human T lymphocytes.

  • 130.
    Bas, A
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Immunology/Immunchemistry.
    Forsberg, G
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Immunology/Immunchemistry. Umeå University, Faculty of Medicine, Department of Clinical Sciences, Paediatrics.
    Sjöberg, Veronika
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Immunology/Immunchemistry.
    Hammarström, Sten
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Immunology/Immunchemistry.
    Hernell, Olle
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Paediatrics.
    Hammarström, Marie-Louise
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Immunology/Immunchemistry.
    Aberrant extrathymic T cell receptor gene rearrangement in the small intestinal mucosa: a risk factor for coeliac disease?2009In: Gut, ISSN 0017-5749, E-ISSN 1468-3288, Vol. 58, no 2, p. 189-195Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Coeliac disease is a small intestine enteropathy caused by permanent intolerance to wheat gluten. Gluten intake by patients with coeliac disease provokes a strong reaction by intestinal intraepithelial lymphocytes (IELs), which normalises on a gluten-free diet. AIM: To investigate whether impaired extrathymic T cell maturation and/or secondary T cell receptor (TCR) gene recombination in IELs are features of coeliac disease which could contribute to the failure of establishing tolerance to gluten.

    METHODS: Expression levels of the four splice-forms of recombination activating gene-1 (RAG1) mRNA and preT alpha-chain (preTalpha) mRNA were determined in IEL-subsets of children with coeliac disease and controls. Frequencies of RAG1 expressing IELs were determined by immunomorphometry.

    RESULTS: In controls, the RAG1-1A/2 splice-form selectively expressed outside the thymus, was dominant and expressed in both mature (TCR(+)) and immature (CD2(+)CD7(+)TCR(-)) IELs ( approximately 8 mRNA copies/18S rRNA U). PreTalpha was expressed almost exclusively in CD2(+)CD7(+)TCR(-) IELs ( approximately 40 mRNA copies/18S rRNA U). By contrast, RAG1 and preTalpha mRNA levels were low in patients with coeliac disease compared to controls, both with active disease and with inactive, symptom-free disease on a gluten-free diet (p values <0.01 for mature and <0.05 for immature IELs). Similarly, the frequencies of RAG1+ IELs were significantly lower in patients with coeliac disease compared to controls (p<0.001).

    CONCLUSIONS: Patients with coeliac disease appear to have an impaired capacity for extrathymic TCR gene rearrangement. This is an inherent feature, which probably plays a pivotal role in the failure to efficiently downregulate the T cell response to gluten.

  • 131.
    Bas, Anna
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology.
    Extrathymic T cell receptor gene rearrangement in human alimentary tract2003Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    T lymphocytes regulate the initiation, duration, and magnitude of adaptive immune responses and function as effector cells in cell mediated immunity. To become immunologically competent they must generate functional antigen receptors. This process takes place in the thymus and requires somatic recombination of T cell receptor (TCR) genes. It is mediated by the endonucleases recombination activating gene-1 (RAG1) and RAG2. Although the thymus regresses at puberty, T cells are present throughout life implying that other tissues must provide the proper milieu for T cell development. This thesis describes extrathymic T cell maturation in man. RAG1, RAG2, and the preTα-chain (pTα), which is exclusively utilized in developing T cells, were used as markers for TCR gene rearrangement. Two new exons (1A and 1B) encoding sequences in the 5’ untranslated region (5’UTR) of mRNA were discovered in the human RAG1 gene. The previously described 5’UTR exon (renamed 1C) was located between the new exons and exon 2, the latter containing the entire coding sequence. We found that small intestinal lymphocytes of the T cell lineage expressed the new exons in three different splice forms. RAG1 mRNA containing the 1C exon was not expressed in small intestinal lymphocytes. In contrast, splice forms containing the 1A exon were not expressed in thymocytes. RAG1 and pTα mRNA expressing lymphocytes were seen both within the epithelium and in lamina propria. Thymocyte-like CD2+CD7+CD3-, CD4+CD8+, CD1a+, and IL7-R+ lymphocytes were identified in the small intestinal mucosa. CD2+CD7+CD3- cells had the highest expression levels of mRNA for RAG1 and pTα, suggesting that the small intestinal mucosa is indeed a site for T cell maturation. Small intestinal T lymphocytes were also shown to kill via the Fas/FasL pathway in a TCR/CD3 independent manner and via the perforin/granzyme pathway in a TCR/CD3 dependent manner. The Fas/FasL-mediated cytotoxicity may reflect an ongoing selection process of extrathymically maturated T cells.

    The nasopharyngeal tonsil is the major inductive site for immune reactions against inhaled antigens. Previous demonstration of RAG1 expression in tonsillar B cells was interpreted as antigen driven receptor revision. The present study confirms the expression of RAG1 in B cells. We also found that RAG1, RAG2, and pTa mRNAs were expressed in lymphocytes of the T cell lineage. A small population of cells with the immature phenotype CD2+CD7+CD3- was demonstrated. This population had the highest expression levels of mRNA for RAG1, RAG2, pTα and terminal deoxynucleotidyl transferase. All four splice-forms of RAG1 mRNA were expressed. RAG1 and pTα mRNA expressing cells were mainly located in the proximity of the surface epithelium and in the outer rim of the follicles. These results suggest that the nasopharyngeal tonsil is a site where extrathymic T cell development and antigen driven TCR revision are occurring in parallel.

    Celiac disease (CD) is a small intestinal enteropathy characterized by permanent intolerance to gluten. Gluten reactive intestinal T cells are central in the pathogenesis and CD can be regarded as a failure to maintain tolerance to this food antigen. Expression of the RAG1 1A/2 splice form was significantly decreased in small intestinal T cell subsets of CD patients suggesting that impaired TCR gene rearrangement could contribute to failure of maintain tolerance in CD.

    Together, these findings show that both small intestinal and nasopharyngeal tonsillar lymphocytes of T cell lineage have the molecular machinery for antigen receptor rearrangement and that thymocyte-like lymphocytes are present in both tissues. Thus these organs are likely sites of T lymphocyte ontogeny as well as for secondary T cell receptor rearrangement in man.

  • 132.
    Bas, Anna
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology.
    Forsberg, Göte
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology. Umeå University, Faculty of Medicine, Department of Clinical Sciences, Paediatrics.
    Hammarström, Sten
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology.
    Hammarström, Marie-Louise
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology.
    Utility of the housekeeping genes 18S rRNA, β-actin, and glyceraldehyde-3-phosphate-dehydrogenase (GAPDH) for normalisation in real-time quantitative RT-PCR analysis of gene expression in human T lymphocytes2004In: Scandinavian Journal of Immunology, ISSN 0300-9475, E-ISSN 1365-3083, Vol. 59, no 6, p. 566-573Article in journal (Refereed)
    Abstract [en]

    The accuracy of 18S rRNA, β-actin mRNA and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) mRNA as indicators of cell number when used for normalization in gene expression analysis of T lymphocytes at different activation stages was investigated. Quantitative real-time reverse transcriptase-polymerase chain reaction was used to determine the expression level of 18S rRNA, β-actin mRNA, GAPDH mRNA and mRNA for six cytokines in carefully counted samples of resting human peripheral blood mononuclear cells (PBMCs), intestinal lymphocytes and PBMCs subjected to polyclonal T-cell activation. The 18S rRNA level in activated and resting PBMCs and intestinal lymphocytes was essentially the same, while the levels of β-actin and GAPDH mRNAs fluctuated markedly upon activation. When isolated γδTCR+, CD4+ and CD8+ subpopulations were studied, 18S rRNA levels remained unchanged after 21 h of activation but increased slightly after 96 h. In contrast, there was a 30–70-fold increase of GAPDH mRNA/cell in these cell populations upon activation. Cytokine analysis revealed that only normalization to 18S rRNA gave a result that satisfactorily reflected their mRNA expression levels per cell. In conclusion, 18S rRNA was the most stable housekeeping gene and hence superior for normalization in comparative analyses of mRNA expression levels in human T lymphocytes.

  • 133.
    Bas, Anna
    et al.
    Umeå University, Faculty of Medicine, Clinical Microbiology.
    Forsberg, Göte
    Hernell, Olle
    Hammarström, Sten
    Hammarström, Marie-Louise
    Changes in T cell receptor gene rearrangement in the small intestinal mucosa of children with celiac diseaseManuscript (Other academic)
  • 134.
    Bas, Anna
    et al.
    Umeå University, Faculty of Medicine, Clinical Microbiology.
    Hammarström, Sten
    Hammarström, Marie-Louise
    Extrathymic TCR gene rearrangement in human small intestine: identification of new splice forms of recombination activating gene-1 mRNA with selective tissue expression2003In: The Journal of Immunology, Vol. 171, p. 3359-2271Article in journal (Refereed)
  • 135. Bas, Anna
    et al.
    Hammarström, Sten
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Immunology/Immunchemistry.
    Hammarström, Marie-Louise
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Immunology/Immunchemistry.
    Extrathymic TCR gene rearrangement in human small intestine: identification of new splice forms of recombination activating gene-1 mRNA with selective tissue expression.2003In: Journal of Immunology, ISSN 0022-1767, E-ISSN 1550-6606, Vol. 171, no 7, p. 3359-71Article in journal (Refereed)
    Abstract [en]

    Two new 5'-untranslated region (5'UTR) exons were identified in the human gene for the lymphocyte-specific endonuclease recombination activating gene-1 (RAG1) required for the somatic recombination yielding functional Ag receptors. These 5'UTR exons were used in three different splice forms by jejunal lymphocytes of the T cell lineage. RAG1 mRNA containing the previously described 5'UTR exon was not expressed in these cells. Conversely, one of the new 5'UTR exons was not expressed in thymus. The new RAG1 mRNA splice forms were all expressed in immature T cells (CD2(+)CD7(+)CD3(-)). This cell population also expressed high levels of mRNA for the pre-T alpha-chain. In situ hybridization demonstrated jejunal cells expressing the new splice forms of RAG1 mRNA, both intraepithelially and in lamina propria. Pre-T alpha-chain mRNA-expressing cells were detected at the same sites. These results strongly suggest ongoing TCR gene rearrangement in human small intestinal mucosa, yielding T cells specially adapted for this environment. This seems to be achieved by two parallel processes, extrathymic T cell development and peripheral Ag-driven TCR editing.

  • 136.
    Bas, Anna
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology.
    Hammarström, Sten
    Hellström, Sten
    Hammarström, Marie-Louise
    The nasopharyngeal tonsil - a site for T cell receptor gene rearrangement in manManuscript (preprint) (Other academic)
  • 137. Bashir, Rania Salah Eldien
    et al.
    Hassan, Osama Ahmed
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Section of Virology.
    A One Health perspective to identify environmental factors that affect Rift Valley fever transmission in Gezira state, Central Sudan2019In: Tropical Medicine and Health, ISSN 1348-8945, E-ISSN 1349-4147, Vol. 47, no 1, article id 54Article in journal (Refereed)
    Abstract [en]

    Background: Rift Valley fever (RVF) is a zoonotic viral vector-borne disease that affects both animals and humans and leads to severe economic consequences. RVF outbreaks are triggered by a favorable environment and flooding, which enable mosquitoes to proliferate and spread the virus further. RVF is endemic to Africa and has spread to Saudi Arabia and Yemen. There is great concern that RVF may spread to previously unaffected geographic regions due to climate change. We aimed to better understand the spatiotemporal pattern of the 2007 RVF outbreak at the human-animal-environment interface and to determine environmental factors that may have effects on RVF occurrence in Gezira state, Sudan.

    Materials and methods: We compiled epidemiological, environmental, and spatiotemporal data across time and space using remote sensing and a geographical information system (GIS). The epidemiological data included 430 RVF human cases as well as human and animal population demographic data for each locality. The cases were collected from 41 locations in Gezira state. The environmental data represent classified land cover during 2007, the year of the RVF outbreak, and the average of the Normalized Difference Vegetation Index (NDVI) for 6 months of 2007 is compared with those of 2010 and 2014, when there was no RVF outbreak. To determine the effect of the environmental factors such as NDVI, soil type, and RVF case's location on the Blue Nile riverbank on RVF incidence in Gezira state, a multilevel logistic regression model was carried out.

    Results: We found that the outbreak in Gezira state occurred as a result of interaction among animals, humans, and the environment. The multilevel logistic regression model (F = 43,858, df = 3, p = 0.000) explained 23% of the variance in RVF incidence due to the explanatory variables. Notably, soil type (beta = 0.613, t = 11.284, p = 0.000) and NDVI (beta = - 0.165, t = - 3.254, p = 0.001) were the explanatory environmental factors that had significant effects on RVF incidence in 2007 in Gezira state, Sudan.

    Conclusions: Precise remote sensing and the GIS technique, which rely on environmental indices such as NDVI and soil type that are satellite-derived, can contribute to establishing an early warning system for RVF in Sudan. Future preparedness and strengthening the capacity of regional laboratories are necessary for early notification of outbreaks in animals and humans.

  • 138.
    Baudin, Maria
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Virology.
    Rift Valley fever: consequences of virus-host interactions2016Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Rift Valley fever virus (RVFV) is a mosquito-borne virus which has the ability to infect a large variety of animals including humans in Africa and Arabian Peninsula. The abortion rate among these animals are close to 100%, and young animals develop severe disease which often are lethal.

    In humans, Rift Valley fever (RVF) presents in most cases as a mild illness with influenza-like symptoms. However, in about 8% of the cases it progresses into a more severe disease with a high case fatality rate. Since there is such a high abortion rate among infected animals, a link between human miscarriage and RVFV has been suggested, but never proven.

    We could in paper I for the first time show an association between acute RVFV infection and miscarriage in humans. We observed an increase in pregnant women arriving at the Port Sudan Hospital with fever of unknown origin, and several of the patients experienced miscarriage. When we analysed their blood samples for several viral diseases we found that many had an acute RVFV infection and of these, 54% experienced a miscarriage. The odds of having a miscarriage was 7 times higher for RVFV patients compared to the RVFV negative women of which only 12% miscarried. These results indicated that RVFV infection could be a contributing factor to miscarriage.

    RVFV is an enveloped virus containing the viral glycoproteins n and c (Gn and Gc respectively), where Gn most likely is responsible for the initial cellular contact. The protein DC-SIGN on dendritic cells and the glycosaminoglycan heparan sulfate has been suggested as cellular receptors for RVFV, however other mechanisms are probably also involved in binding and entry. Charge is a driving force for molecular interaction and has been shown to be important for cellular attachment of several viruses, and in paper II we could show that when the charge around the cells was altered, the infection was affected. We also showed that Gn most likely has a positive charge at a physiological pH.

    When we added negatively charged molecules to the viral particles before infection, we observed a decreased infection efficiency, which we also observed after removal of carbohydrate structures from the cell surface.

    Our results suggested that the cellular interaction partner for initial attachment is a negatively charged carbohydrate. Further investigations into the mechanisms of RVFV cellular interactions has to be undertaken in order to understand, and ultimately prevent, infection and disease.

    There is currently no vaccine approved for human use and no specific treatments for RVF, so there is a great need for developing safe effective drugs targeting this virus. We designed a whole-cell based high-throughput screen (HTS) assay which we used to screen libraries of small molecular compounds for anti-RVFV properties. After dose-response and toxicity analysis of the initial hits, we identified six safe and effective inhibitors of RVFV infection that with further testing could become drug candidates for treatment of RVF. This study demonstrated the application of HTS using a whole-cell virus replication reporter gene assay as an effective method to identify novel compounds with potential antiviral activity against RVFV.

  • 139.
    Baudin, Maria
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Biomedical Laboratory Science.
    Ökad trombopoes och perifer trombocytaktivering i Hantavirus-infekterade patienter2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 140.
    Baudin, Maria
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Virology.
    Hossain, Delowar
    Evander, Magnus
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Virology.
    Importance of charge interactions in Rift Valley fever virus attachment to host cellsManuscript (preprint) (Other academic)
    Abstract [en]

    The mosquito-borne Rift Valley fever virus (RVFV) cause disease in both humans and animals and can infect a large range of animals as well as humans. Many different cell types are infected both in vivo and in vitro. To enter a cell the virus needs to attach and enter, and this initial binding to the host cell surface could depend on both general mechanisms, and different specific receptors. Our aim was to characterize determinants for RVFV entry into its host cells.To examine RVFV attachment to host cells we based our experimental assay on RVF virus-like particles containing a reporter gene. The enveloped RVFV uses protruding glycoproteins (Gn and Gc) for attachment and entry and to investigate potential virus-cell surface interactions, the net surface charge of the glycoproteins was first calculated. The RVFV glycoprotein Gn had a predicted isoelectric point (pI) of 7.6 and a net positive charge of +6.9 at pH 7.0, suggesting a charge interaction between the Gn ectodomain and the negatively charged cell surface. RVFV Gc on the other hand, was highly negatively charged, -12.8 at neutral pH, most probably reflecting that Gc is not exposed until after receptor binding. To characterize the general conditions needed for RVFV attachment, cells or virus were treated with various compounds. Both sodium chloride and the negatively charged heparin inhibited RVF virus-like particle infection, strongly indicating that viral binding was charge-dependent. Treatment with sodium periodate pointed to a carbohydrate structure as a cellular interaction partner. Removal of sialic acid or heparan sulfate receptors on the cell surface by enzymatic treatment and blocking of the heparan sulfate receptor did not inhibit virus attachment.In conclusion, RVFV binding to host cells was charge dependent and the results point to a carbohydrate structure with negative charge as a potential attachment factor.

  • 141.
    Baudin, Maria
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Virology.
    Jumaa, Ammar M.
    Jomma, Huda J. E.
    Karsany, Mubarak S.
    Bucht, Göran
    Näslund, Jonas
    Ahlm, Clas
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Infectious Diseases.
    Evander, Magnus
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Virology.
    Mohamed, Nahla
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Virology.
    Association of Rift Valley fever virus infection with miscarriage in Sudanese women: a cross-sectional study2016In: The Lancet Global Health, E-ISSN 2214-109X, Vol. 4, no 11, p. e864-e871Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Rift Valley fever virus is an emerging mosquito-borne virus that causes infections in animals and human beings in Africa and the Arabian Peninsula. Outbreaks of Rift Valley fever lead to mass abortions in livestock, but such abortions have not been identified in human bezings. Our aim was to investigate the cause of miscarriages in febrile pregnant women in an area endemic for Rift Valley fever.

    METHODS: Pregnant women with fever of unknown origin who attended the governmental hospital of Port Sudan, Sudan, between June 30, 2011, and Nov 17, 2012, were sampled at admission and included in this cross-sectional study. Medical records were retrieved and haematological tests were done on patient samples. Presence of viral RNA as well as antibodies against a variety of viruses were analysed. Any association of viral infections, symptoms, and laboratory parameters to pregnancy outcome was investigated using Pearson's χ(2) test.

    FINDINGS: Of 130 pregnant women with febrile disease, 28 were infected with Rift Valley fever virus and 31 with chikungunya virus, with typical clinical and laboratory findings for the infection in question. 15 (54%) of 28 women with an acute Rift Valley fever virus infection had miscarriages compared with 12 (12%) of 102 women negative for Rift Valley fever virus (p<0·0001). In a multiple logistic regression analysis, adjusting for age, haemorrhagic disease, and chikungunya virus infection, an acute Rift Valley fever virus infection was an independent predictor of having a miscarriage (odds ratio 7·4, 95% CI 2·7-20·1; p<0·0001).

    INTERPRETATION: This study is the first to show an association between infection with Rift Valley fever virus and miscarriage in pregnant women. Further studies are warranted to investigate the possible mechanisms. Our findings have implications for implementation of preventive measures, and evidence-based information to the public in endemic countries should be strongly recommended during Rift Valley fever outbreaks.

    FUNDING: Schlumberger Faculty for the Future, CRDF Global (31141), the Swedish International Development Cooperation Agency, the County Council of Västerbotten, and the Faculty of Medicine, Umeå University.

  • 142. Bazarian, Jeffrey J
    et al.
    Zemlan, Frank P
    Mookerjee, Sohug
    Stigbrand, Torgny
    Umeå University, Faculty of Medicine, Clinical Microbiology. Umeå University, Faculty of Medicine, Clinical Microbiology, Immunology/Immunchemistry.
    Serum S-100B and cleaved-tau are poor predictors of long-term outcome after mild traumatic brain injury.2006In: Brain Injury, ISSN 0269-9052, E-ISSN 1362-301X, Vol. 20, no 7, p. 759-65Article in journal (Refereed)
    Abstract [en]

    PRIMARY OBJECTIVE: To determine the relationship of serum S-100B and C-tau levels to long-term outcome after mild traumatic brain injury (mild TBI). RESEARCH DESIGN: A prospective study of 35 mild TBI subjects presenting to the emergency department. METHODS AND PROCEDURES: Six hour serum S-100B and C-tau levels compared to 3-month Rivermead Post Concussion Questionnaire (RPCQ) scores and post-concussive syndrome (PCS). MAIN OUTCOMES AND RESULTS: The linear correlation between marker levels and RPCQ scores was weak (S-100B: r = 0.071, C-tau: r = -0.21). There was no statistically significant correlation between marker levels and 3-month PCS (S-100B: AUC = 0.589, 95%CI. 038, 0.80; C-tau: AUC = 0.634, 95%CI 0.43, 0.84). The sensitivity of these markers ranged from 43.8-56.3% and the specificity from 35.7-71.4%. CONCLUSIONS: Initial serum S-100B and C-tau levels appear to be poor predictors of 3-month outcome after mild TBI.

  • 143. Bengtsson-Palme, Johan
    et al.
    Angelin, Martin
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Infectious Diseases.
    Huss, Mikael
    Kjellqvist, Sanela
    Kristiansson, Erik
    Palmgren, Helena
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Infectious Diseases.
    Larsson, D. G. Joakim
    Johansson, Anders
    Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Clinical Bacteriology.
    The Human Gut Microbiome as a Transporter of Antibiotic Resistance Genes between Continents2015In: Antimicrobial Agents and Chemotherapy, ISSN 0066-4804, E-ISSN 1098-6596, Vol. 59, no 10, p. 6551-6560Article in journal (Refereed)
    Abstract [en]

    Previous studies of antibiotic resistance dissemination by travel have, by targeting only a select number of cultivable bacterial species, omitted most of the human microbiome. Here, we used explorative shotgun metagenomic sequencing to address the abundance of >300 antibiotic resistance genes in fecal specimens from 35 Swedish students taken before and after exchange programs on the Indian peninsula or in Central Africa. All specimens were additionally cultured for extended-spectrum beta-lactamase (ESBL)-producing enterobacteria, and the isolates obtained were genome sequenced. The overall taxonomic diversity and composition of the gut microbiome remained stable before and after travel, but there was an increasing abundance of Proteobacteria in 25/35 students. The relative abundance of antibiotic resistance genes increased, most prominently for genes encoding resistance to sulfonamide (2.6-fold increase), trimethoprim (7.7-fold), and beta-lactams (2.6-fold). Importantly, the increase observed occurred without any antibiotic intake. Of 18 students visiting the Indian peninsula, 12 acquired ESBL-producing Escherichia coli, while none returning from Africa were positive. Despite deep sequencing efforts, the sensitivity of metagenomics was not sufficient to detect acquisition of the low-abundant genes responsible for the observed ESBL phenotype. In conclusion, metagenomic sequencing of the intestinal microbiome of Swedish students returning from exchange programs in Central Africa or the Indian peninsula showed increased abundance of genes encoding resistance to widely used antibiotics.

  • 144.
    Berg, Hannah
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Virology.
    Mosquito-borne viruses in northern Sweden2016Independent thesis Basic level (professional degree), 20 credits / 30 HE creditsStudent thesis
  • 145.
    Berg, Johanna
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Biomedical Laboratory Science.
    Visualisering av mikroorganismer i hårfolliklar från patienter med follikulit2012Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 146.
    Berg, Mari
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Biomedical Laboratory Science. Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Clinical Bacteriology.
    Utvärdering av Sysmex UF-5000 för snabb antibiotikaresistens­bestämning av bakterier2018Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
  • 147.
    Berggren, Kevin
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Biomedical Laboratory Science.
    Metodvalidering av IGF-1 med ECLIA på Cobas e601 system2019Independent thesis Advanced level (professional degree), 10 credits / 15 HE creditsStudent thesis
  • 148.
    Bergh Drott, Johanna
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology.
    The role of microorganisms in prostate cancer development2012Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Prostate cancer is the most common cancer among Swedish men, but the aetiology of this disease is largely unknown. There is evidence for a linkage between chronic inflammation and prostate cancer. The mechanisms causing prostate inflammation and how this could promote tumour development and progression are however largely unknown. Chronic inflammatory infiltrates are common findings in prostate tissue samples and infection is proposed to be one possible cause for this inflammation. Inflammatory cells release free radicals, cytokines, and growth factors that facilitate increased cell proliferation, DNA damage, mutations, and angiogenesis. However, the present literature on the presence of microbes in prostate tissue and their possible linkage to inflammation and cancer development is limited. Therefore, the aim of this thesis was to investigate if microorganisms are present in prostate tissue and to evaluate their role in inducing prostatitis and prostate epithelial neoplasia.

    The presence of microorganisms (virus, bacteria and fungi) was studied in clinical prostate tissue samples to evaluate whether or not the occurrences of microorganisms were different in patients that later developed cancer compared with matched controls that did not. Viruses, bacteria and fungi were found in prostate tissues. Out of eight different viruses investigated, EBV and JC virus were detected, but there were no differences in occurrence in the case group compared to the control group. The fungus Candida albicans was present in a very small proportion of the prostate tissue samples. The predominant bacterium was Propionibacterium acnes and the second most prevalent was Escherichia coli. The presence of Propionibacterium acnes was associated with inflammation and subsequent prostate cancer development. Propionibacterium acnes was further evaluated for its capacity to induce an inflammatory response both in vitro and in vivo. Live Propionibacterium acnes induced a strong immune reaction in prostate epithelial cells in vitro with up-regulation of inflammatory genes and secretion of pro-inflammatory cytokines. Infection with Propionibacterium acnes in rat prostate resulted in a lobe specific inflammation with the most intense inflammation in the dorso-lateral prostate, lasting up to 3 months post-inoculation. Propionibacterium acnes inflammation was also associated with altered epithelial cell morphology, signs of DNA damage and increased cell proliferation.

    Taken together, this thesis shows that different viruses and bacteria can be found in prostate tissue. Propionibacterium acnes, the most abundant among the bacteria detected and more prevalent in the cancer than in the control group, exhibits strong prostatitis promoting properties both in vitro and in vivo. In addition, Propionibacterium acnes can induce some of the epithelial changes known to occur during prostate neoplasia formation. This thesis therefore suggests that Propionibacterium acnes induced chronic prostatitis could promote prostate cancer development. Further studies are needed to elucidate the molecular interplay linking Propionibacterium acnes induced inflammation and the formation of a pre-neoplastic state that could evolve into prostate cancer.

  • 149.
    Bergh Drott, Johanna
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Virology.
    Alexeyev, Oleg
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Virology.
    Bergström, Patrik
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Virology.
    Elgh, Fredrik
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Virology.
    Olsson, Jan
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Virology.
    Propionibacterium acnes infection induces upregulation of inflammatory genes and cytokine secretion in prostate epithelial cells2010In: BMC Microbiology, ISSN 1471-2180, E-ISSN 1471-2180, Vol. 10, p. 126-Article in journal (Refereed)
    Abstract [en]

    Background: The immune stimulating bacterium Propionibacterium acnes is a frequent colonizer of benign and malignant prostate tissue. To understand the pathogenesis of the earliest phase of this infection, we examined the P. acnes triggered immune response in cultivated prostate epithelial cells.

    Results: Prostate epithelial cells are triggered to secrete IL-6, IL-8 and GM-CSF when infected with P. acnes. The secretion of cytokines is accompanied by NFκB related upregulation of the secreted cytokines as well as several components of the TLR2-NFκB signaling pathway.

    Conclusions: P. acnes has potential to trigger a strong immune reaction in the prostate glandular epithelium. Upon infection of prostate via the retrograde urethral route, the induced inflammatory reaction might facilitate bacterial colonization deeper in the prostate tissue where persistent inflammation may impact the development of prostate diseases as hyperplasia and/or malignancy.

  • 150.
    Bergh Drott, Johanna
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology.
    Olsson, Jan
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology.
    Elgh, Fredrik
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology.
    Bergh, Anders
    Umeå University, Faculty of Medicine, Department of Medical Biosciences.
    Rudolfsson, Stina
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences.
    Propionibacterium acnes induces chronic inflammation and precancerous epithelial lesions in the dorso-lateral prostate in ratsManuscript (preprint) (Other academic)
1234567 101 - 150 of 1695
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf