| 1. |
- Conlan, J Wayne, et al.
(författare)
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Molecular immunology of experimental primary tularemia in mice infected by respiratory or intradermal routes with type A Francisella tularensis.
- 2008
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Ingår i: Molecular Immunology. - : Elsevier BV. - 0161-5890 .- 1872-9142. ; 45:10, s. 2962-2969
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Tidskriftsartikel (refereegranskat)abstract
- The type A subspecies of Francisella tularensis is a highly virulent facultative intracellular bacterial pathogen, and a potential biological weapon. Recently, there has been renewed interest in developing new vaccines and therapeutics against this bacterium. Natural cases of disease, tularemia, caused by the type A subspecies are very rare. Therefore, the United States Food and Drug Administration will rely on the so-called Animal Rule for efficacy testing of anti-Francisella medicines. This requires the human disease to be modeled in one or more animal species in which the pathogenicity of the agent is reasonably well understood. Mice are natural hosts for F. tularensis, and might be able to satisfy this requirement. Tularemia pathogenesis appears to be primarily due to the host inflammatory response which is poorly understood at the molecular level. Additionally, the extent to which this response varies depending on host and pathogen genetic background, or by pathogen challenge route or dose is unknown. Therefore, the present study examined sera and infected tissues from C57BL/6 and BALB/c mice challenged by natural intradermal (ID) and respiratory routes with one of two distinct type A strains of the pathogen for cytokine and chemokine responses that might help to explain the morbidity associated with tularemia. The results show that the molecular immune response was mostly similar regardless of the variables examined. For instance, mRNA for the proinflammatory cytokine IL-6, and chemokines KC, and IP-10 was consistently upregulated at all sites of infection. Upregulation of mRNA for several other cytokines and chemokines occurred in a more tissue restricted manner. For instance, IFN-gamma was highly upregulated in the skin of BALB/c, but not C57BL/6 mice after ID inoculation of the pathogen, whilst IL-10 mRNA upregulation was only consistently seen in the skin and lungs.
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| 2. |
- Eneslätt, Kjell, et al.
(författare)
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Persistence of cell-mediated immunity three decades after vaccination with the live vaccine strain of Francisella tularensis
- 2011
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Ingår i: European Journal of Immunology. - Weinheim : Wiley-VCH Verlagsgesellschaft. - 0014-2980 .- 1521-4141. ; 41:4, s. 974-980
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Tidskriftsartikel (refereegranskat)abstract
- The efficacy of many vaccines against intracellular bacteria depends on the generation of cell-mediated immunity, but studies to determine the duration of immunity are usually confounded by re-exposure. The causative agent of tularemia, Francisella tularensis, is rare in most areas and, therefore, tularemia vaccination is an interesting model for studies of the longevity of vaccine-induced cell-mediated immunity. Here, lymphocyte proliferation and cytokine production in response to F. tularensis were assayed in two groups of 16 individuals, vaccinated 1-3 or 27-34 years previously. As compared to naïve individuals, vaccinees of both groups showed higher proliferative responses and, out of 17 cytokines assayed, higher levels of MIP-1β, IFN-γ, IL-10, and IL-5 in response to recall stimulation. The responses were very similar in the two groups of vaccinees. A statistical model was developed to predict the immune status of the individuals and by use of two parameters, proliferative responses and levels of IFN-γ, 91.1% of the individuals were correctly classified. Using flow cytometry analysis, we demonstrated that during recall stimulation, expression of IFN-γ by CD4(+) CCR7(+) , CD4(+) CD62L(+) , CD8(+) CCR7(+) , and CD8(+) CD62L(+) cells significantly increased in samples from vaccinated donors. In conclusion, cell-mediated immunity was found to persist three decades after tularemia vaccination without evidence of decline.
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| 3. |
- Eneslätt, Kjell, et al.
(författare)
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Signatures of T cells as correlates of immunity to Francisella tularensis
- 2012
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 7:3, s. e32367-
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Tidskriftsartikel (refereegranskat)abstract
- Tularemia or vaccination with the live vaccine strain (LVS) of Francisella tularensis confers long-lived cell-mediated immunity. We hypothesized that this immunity depends on polyfunctional memory T cells, i.e., CD4(+) and/or CD8(+) T cells with the capability to simultaneously express several functional markers. Multiparametric flow cytometry, measurement of secreted cytokines, and analysis of lymphocyte proliferation were used to characterize in vitro recall responses of peripheral blood mononuclear cells (PBMC) to killed F. tularensis antigens from the LVS or Schu S4 strains. PBMC responses were compared between individuals who had contracted tularemia, had been vaccinated, or had not been exposed to F. tularensis (naive). Significant differences were detected between either of the immune donor groups and naive individuals for secreted levels of IL-5, IL-6, IL-10, IL-12, IL-13, IFN-gamma, MCP-1, and MIP-1 beta. Expression of IFN-gamma, MIP-1 beta, and CD107a by CD4(+)CD45RO(+) or CD8(+) CD45RO(+) T cells correlated to antigen concentrations. In particular, IFN-gamma and MIP-1 beta strongly discriminated between immune and naive individuals. Only one cytokine, IL-6, discriminated between the two groups of immune individuals. Notably, IL-2- or TNF-alpha-secretion was low. Our results identify functional signatures of T cells that may serve as correlates of immunity and protection against F. tularensis.
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| 4. |
- Rietz, Cecilia, 1970-
(författare)
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Molecular and cellular mechanisms in the development of IDDM in non-obese diabetic mice
- 2000
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Insulin dependent diabetes mellitus (IDDM) is a disease caused by autoimmune destruction of the insulin producing b cells in the pancreas. The leukocytic infiltration into the b cell islets preceding disease is called insulitis. The non-obese diabetic (NOD) mouse, a useful model to study IDDM, spontaneously develops diabetes similar to the human disease. IDDM is strongly associated with genes in the major histocompatibility complex (MHC) class II region. NOD mice lack expression of the MHC class II E complex due to a deletion in the Ea gene. Transgenic insertion of an Ea gene, restoring E complex expression, protects the mice from insulitis. In this study mechanisms behind protection against insulitis are investigated in Ea-transgenic NOD mice. Three different mutated Ea transgenic mouse strains, with restricted E complex expression, were bred together to investigate the correlation between E complex expression patterns and insulitis. The results indicate that minute quantitative disturbances on peripheral immune cells may affect the level of protection. A bone marrow transfer model shows that for an optimal protection from insulitis, which is correlated with optimal levels of interleukin (IL)-4, E complex expression is necessary on both thymic epithelium and bone marrow derived cells. However, Ea transgenic NOD mice lacking the IL-4 gene still display protection from insulitis indicating that in the absence of IL-4, other cytokines may compensate for the protective effect. Ea transgenic mice were also used to study the correlation between defects in the VH (immunoglobulin heavy variable) gene utilization repertoire and development of disease in NOD mice. Protected Ea transgenic NOD mice display a similarly biased VH utilization pattern, suggesting that the bias in VH gene usage in NOD mice is not directly correlated to development of disease. Analysis of VH gene expression in mice transgenic for the apoptosis inhibitor bcl-2 indicates that a biased VH gene utilization may be correlated to an increased expression of Bcl-2. NOD mice transgenic for Bcl-2 over-expressed in B and T cells showed protection from insulitis, whereas no effect could be seen in mice only expressing the bcl-2 transgene in B cells. Analysis of T cell subsets in the protected bcl-2 transgenic mice did not reveal expansion of any of the major subsets in spleen or thymus.
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| 5. |
- Svensson, Teresia, et al.
(författare)
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Influence of Multiple Environmental Factors on Organic Matter Chlorination in Podsol Soil
- 2017
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 51:24, s. 14114-14123
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Tidskriftsartikel (refereegranskat)abstract
- Natural chlorination of organic matter is common in soils. The abundance of chlorinated organic compounds frequently exceeds chloride in surface soils, and the ability to chlorinate soil organic matter (SOM) appears widespread among microorganisms. Yet, the environmental control of chlorination is unclear. Laboratory incubations with Cl-36 as a Cl tracer were performed to test how combinations of environmental factors, including levels of soil moisture, nitrate, chloride, and labile organic carbon, influenced chlorination of SOM from a boreal forest. Total chlorination was hampered by addition of nitrate or by nitrate in combination with water but enhanced by addition of chloride or most additions including labile organic matter (glucose and maltose). The greatest chlorination was observed after 15 days when nitrate and water were added together with labile organic matter. The effect that labile organic matter strongly stimulated the chlorination rates was confirmed by a second independent experiment showing higher stimulation at increased availability of labile organic matter. Our results highlight cause-effect links between chlorination and the studied environmental variables in podsol soil-with consistent stimulation by labile organic matter that did overrule the negative effects of nitrate.
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