| 1. |
- Dominguez, Cecilia A, et al.
(författare)
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Genetic analysis of neuropathic pain-like behavior following peripheral nerve injury suggests a role of the major histocompatibility complex in development of allodynia
- 2008
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Ingår i: Pain. - : Ovid Technologies (Wolters Kluwer Health). - 1872-6623 .- 0304-3959. ; 136:3, s. 313-319
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Tidskriftsartikel (refereegranskat)abstract
- Neuropathic pain is a common consequence of damage to the nervous system. We here report a genetic analysis of development of neuropathic pain-like behaviors after unilateral photochemically-induced ischemic sciatic nerve injury in a panel of inbred rat strains known to display different susceptibility to autoimmune neuroinflammation. Pain behavior was initially characterized in Dark-Agouti (DA; RT1(avl)), Piebald Virol Glaxo (PVG; RT1(c)), and in the major histocompatibility complex (MHC)-congenic strain PVG-RT1(avl). All strains developed mechanical hypersensitivity (allodynia) following nerve injury. However, the extent and duration of allodynia varied significantly among the strains, with PVG displaying more severe allodynia compared to DA rats. Interestingly, the response of PVG-RT1(avR1) was similar to that of DA, suggesting regulation by the MHC locus. This notion was subsequently confirmed in an F2 cohort derived from crossing of the PVG and PVG-RT1(avl) strains, where allodynia was reduced in homozygous or heterozygous carriers of the RT1(avl) allele in comparison to rats homozygous for the RT1(c) allele. These results indicate that certain allelic variants of the MHC could influence susceptibility to develop and maintain neuropathic pain-like behavior following peripheral nerve injury in rats.
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| 2. |
- Gillett, Alan, et al.
(författare)
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TNF production in macrophages is genetically determined and regulates inflammatory disease in rats.
- 2010
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Ingår i: Journal of immunology (Baltimore, Md. : 1950). - : The American Association of Immunologists. - 1550-6606 .- 0022-1767. ; 185:1, s. 442-50
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Tidskriftsartikel (refereegranskat)abstract
- Dysregulation of TNF is an important pathophysiological phenotype for many diseases. Recently, certain genetically regulated loci have been identified to regulate several inflammatory diseases. We hypothesized that a region on rat chromosome 4 known to regulate experimental autoimmune encephalomyelitis, experimental arthritis and experimental autoimmune neuritis harbors a gene regulating central inflammatory molecules, such as TNF. We therefore mapped TNF production using linkage analysis in the 12th generation of an advanced intercross line between DA and PVG.AV1 rats, which differ in susceptibility to several inflammatory conditions. A single TNF-regulating quantitative trait locus with a logarithm of odds score of 6.2 was identified and its biological effect was confirmed in a congenic rat strain. The profound TNF regulation mapped in congenic strains to the macrophage population. Several TLR signaling cascades led to the same reduced proinflammatory phenotype in congenic macrophages, indicating control of a convergence point for innate inflammatory activity. The decreased TNF potential and reduced proinflammatory macrophage phenotype in congenic rats was also associated with reduced clinical severity in experimental autoimmune encephalomyelitis, pristane-induced arthritis and sepsis experimental models. Determination of genes and mechanisms involved in this genetically determined TNF regulation will be valuable in understanding disease pathogenesis and aid treatment development.
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| 3. |
- Haag, Sabrina, et al.
(författare)
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Positional Identification of RT1-B (HLA-DQ) as Susceptibility Locus for Autoimmune Arthritis
- 2015
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Ingår i: Journal of Immunology. - : The American Association of Immunologists. - 0022-1767 .- 1550-6606. ; 194:6, s. 2539-2550
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Tidskriftsartikel (refereegranskat)abstract
- Rheumatoid arthritis (RA) is associated with amino acid variants in multiple MHC molecules. The association to MHC class II (MHC-II) has been studied in several animal models of RA. In most cases these models depend on T cells restricted to a single immunodominant peptide of the immunizing Ag, which does not resemble the autoreactive T cells in RA. An exception is pristane-induced arthritis (PIA) in the rat where polyclonal T cells induce chronic arthritis after being primed against endogenous Ags. In this study, we used a mixed genetic and functional approach to show that RT1-Ba and RT1-Bb (RT1-B locus), the rat orthologs of HLA-DQA and HLA-DQB, determine the onset and severity of PIA. We isolated a 0.2-Mb interval within the MHC-II locus of three MHC-congenic strains, of which two were protected from severe PIA. Comparison of sequence and expression variation, as well as in vivo blocking of RT1-B and RT1-D (HLA-DR), showed that arthritis in these strains is regulated by coding polymorphisms in the RT1-B genes. Motif prediction based on MHC-II eluted peptides and structural homology modeling suggested that variants in the RT1-B P1 pocket, which likely affect the editing capacity by RT1-DM, are important for the development of PIA.
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| 4. |
- Hoffmann, Markus H., et al.
(författare)
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The rheumatoid arthritis-associated autoantigen hnRNP-A2 (RA33) is a major stimulator of autoimmunity in rats with pristane-induced arthritis
- 2007
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Ingår i: Journal of Immunology. - 1550-6606. ; 179:11, s. 7568-7576
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Tidskriftsartikel (refereegranskat)abstract
- A single intradermal injection of the mineral oil pristane in susceptible DA.1F rats induces erosive arthritis closely mimicking rheumatoid arthritis (RA). Pristane-induced arthritis (PIA) is driven by autoreactive T cells but no autoantigen has been identified to date. We therefore analyzed B and T cell responses to autoantigens potentially involved in the pathogenesis of RA, including IgG, citrullinated proteins, stress proteins, glucose-6-phosphate isomerase, and heterogeneous nuclear ribonucleoprotein (hnRNP)-A2 (RA33). IgG and lgM autoantibodies to hnRNP-A2 were detectable in sera of pristane-primed DA.1F rats already 1 wk before disease onset, reached maximum levels during the acute phase, and correlated with arthritis severity. Apart from rheumatoid factor, autoantibodies to other Ags were not observed. CD4(+) lymph node cells isolated 10 days after pristane injection produced IFN-gamma but not IL-4 in response to stimulation with hnRNP-A2, whereas none of the other candidate Ags elicited cytokine secretion. Surprisingly, hnRNP-A2 also stimulated lymph node cells of naive animals to produce inflammatory cytokines in a MyD88-dependent manner. Furthermore, hnRNP-A2 was highly overexpressed in the joints of rats injected with pristane. Overexpression coincided with the appearance of anti-RA33 Abs and preceded the onset of clinical symptoms of PIA by several days. Taken together, these data suggest hnRNP-A2 to be among the primary inducers of autoimmunity in PIA. Therefore, this Ag might play a pivotal role in the pathogenesis of PIA and possibly also human RA.
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| 5. |
- Holmberg, Jens, et al.
(författare)
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Pristane, a non-antigenic adjuvant, induces MHC class II-restricted, arthritogenic T cells in the rat.
- 2006
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Ingår i: Journal of Immunology. - 1550-6606. ; 176:2, s. 1172-1179
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Tidskriftsartikel (refereegranskat)abstract
- Pristane-induced arthritis (PIA) in rats, a model for rheumatoid arthritis (RA), is a T cell-dependent disease. However, pristane itself is a lipid and unable to form a stable complex with a MHC class II molecule. Therefore, the specificity and function of the T cells in PIA are as unclear as in rheumatoid arthritis. In this study, we show that activated CD4+ alphabetaT cells, which target peripheral joints, transfer PIA. The pristane-primed T cells are of oligo or polyclonal origin as determined by their arthritogenicity after stimulation with several mitogenic anti-TCRVbeta and anti-TCRValpha mAbs. Arthritogenic cells secreted IFN-gamma and TNF-alpha (but not IL-4) when stimulated with Con A in vitro, and pretreatments of recipient rats with either anti-IFN-gamma or a recombinant TNF-alpha receptor before transfer ameliorated arthritis development. Most importantly, we show that these T cells are MHC class II restricted, because treatment with Abs against either DQ or DR molecules ameliorates arthritis development. The MHC class II restriction was confirmed by transferring donor T cells to irradiated recipients that were syngenic, semiallogenic, or allogenic to MHC class II molecules, in which only syngenic and semiallogenic recipients developed arthritis. These data suggest that the in vivo administration of a non-antigenic adjuvant, like pristane, activates CD4+ alphabetaT cells that are MHC class II restricted and arthritogenic.
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| 6. |
- Norin, U., et al.
(författare)
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Endophilin A2 deficiency protects rodents from autoimmune arthritis by modulating T cell activation
- 2021
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- The introduction of the CTLA-4 recombinant fusion protein has demonstrated therapeutic effects by selectively modulating T-cell activation in rheumatoid arthritis. Here we show, using a forward genetic approach, that a mutation in the SH3gl1 gene encoding the endocytic protein Endophilin A2 is associated with the development of arthritis in rodents. Defective expression of SH3gl1 affects T cell effector functions and alters the activation threshold of autoreactive T cells, thereby leading to complete protection from chronic autoimmune inflammatory disease in both mice and rats. We further show that SH3GL1 regulates human T cell signaling and T cell receptor internalization, and its expression is upregulated in rheumatoid arthritis patients. Collectively our data identify SH3GL1 as a key regulator of T cell activation, and as a potential target for treatment of autoimmune diseases. The autoimmune disorder, rheumatoid arthritis (RA), has been associated with multiple pathophysiological factors. Here the authors show that deficiency in endophilin A2 in rodents protects them from experimental arthritis by altering T cell activation threshold and effector functions, thereby hinting a potential target for RA therapy.
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| 7. |
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| 8. |
- Rosengren, Anders, et al.
(författare)
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Overexpression of alpha2A-adrenergic receptors contributes to type 2 diabetes
- 2010
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 1095-9203 .- 0036-8075. ; 327:5962, s. 217-20
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Tidskriftsartikel (refereegranskat)abstract
- Several common genetic variations have been associated with type 2 diabetes, but the exact disease mechanisms are still poorly elucidated. Using congenic strains from the diabetic Goto-Kakizaki rat, we identified a 1.4-megabase genomic locus that was linked to impaired insulin granule docking at the plasma membrane and reduced beta cell exocytosis. In this locus, Adra2a, encoding the alpha2A-adrenergic receptor [alpha(2A)AR], was significantly overexpressed. Alpha(2A)AR mediates adrenergic suppression of insulin secretion. Pharmacological receptor antagonism, silencing of receptor expression, or blockade of downstream effectors rescued insulin secretion in congenic islets. Furthermore, we identified a single-nucleotide polymorphism in the human ADRA2A gene for which risk allele carriers exhibited overexpression of alpha(2A)AR, reduced insulin secretion, and increased type 2 diabetes risk. Human pancreatic islets from risk allele carriers exhibited reduced granule docking and secreted less insulin in response to glucose; both effects were counteracted by pharmacological alpha(2A)AR antagonists.
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| 9. |
- Tuncel, Jonatan
(författare)
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Functional and genetic analyses of the MHC and its impact on autoimmunity in the rat
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The major histocompatibility complex (MHC) is an allele-rich and exceptionally gene dense region on human chromosome 6. Over 40% of the genes in this region have immune-related functions, including genes encoding MHCI and MHCII molecules. These molecules, which are found in nearly all vertebrates, present antigenic peptides to CD4 and CD8 T cells. Alleles of MHCI and MHCII are also believed to be strong risk factors in autoimmune disorders, such as rheumatoid arthritis (RA), as well as in infectious diseases. However, the differentiation between haplotype and allele associations in the MHC is not straightforward. Strong linkage disequilibrium exists between gene segments throughout the region which impedes identification of disease associated variants. These gene segments can be isolated and studied individually in congenic mice and rats. We produced for this thesis an extensive number of intra-MHC congenic rats to study the association between MHC genes and experimental arthritis, T cell selection and MHC regulation. Study I describes a genome-wide approach in heterogenous stock rats to identify quantitative trait loci (QTLs) associated with variations in MHC levels and CD4 and CD8 T cell numbers. A total of 10 QTLs were identified, of which 3 mapped to the MHC. We showed by congenic mapping that two minimal haplotypes of ~0.2 Mb explained the associations to the MHC. We further identified two allelic variants of the gene Tap2 that contributed to the variation in T cell numbers. Study II describes the effect of these minimal haplotypes on arthritis development and positions the MHCII region for the first time in an adjuvant model. We show that genes in the MHCII regulate onset, progression and severity of arthritis but not chronicity. Comparative analyses of different congenic MHCII haplotypes showed an inverse correlation between arthritis severity and a low proportion of recent thymic emigrants. Study III shows an MHCII associated T cell response to the cartilage protein collagen type XI in chronic pristane-induced arthritis (PIA) and the corresponding antibody response to the same antigen in human RA. Study IV describes the adoptive transfer of PIA in DA rats and outlines the conditions necessary for the model.
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| 10. |
- Tuncel, Jonatan, et al.
(författare)
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Self-reactive T cells induce and perpetuate chronic relapsing arthritis
- 2020
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Ingår i: Arthritis Research and Therapy. - : Springer Science and Business Media LLC. - 1478-6354 .- 1478-6362. ; 22:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: CD4+ T cells play a central role during the early stages of rheumatoid arthritis (RA), but to which extent they are required for the perpetuation of the disease is still not fully understood. The aim of the current study was to obtain conclusive evidence that T cells drive chronic relapsing arthritis. Methods: We used the rat pristane-induced arthritis model, which accurately portrays the chronic relapsing-remitting disease course of RA, to examine the contribution of T cells to chronic arthritis. Results: Rats subjected to whole-body irradiation and injected with CD4+ T cells from lymph nodes of pristane-injected donors developed chronic arthritis that lasted for more than 4 months, whereas T cells from the spleen only induced acute disease. Thymectomy in combination with irradiation enhanced the severity of arthritis, suggesting that sustained lymphopenia promotes T cell-driven chronic inflammation in this model. The ability of T cells to induce chronic arthritis correlated with their expression of Th17-associated transcripts, and while depletion of T cells in rats with chronic PIA led to transient, albeit significant, reduction in disease, neutralization of IL-17 resulted in almost complete and sustained remission. Conclusion: These findings show that, once activated, self-reactive T cells can sustain inflammatory responses for extended periods of time and suggest that such responses are promoted in the presence of IL-17.
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