| 1. |
- Ahlqvist, Emma, et al.
(författare)
-
Fragmentation of two quantitative trait loci controlling collagen-induced arthritis reveals a new set of interacting subloci
- 2007
-
Ingår i: Journal of Immunology. - 1550-6606. ; 178:5, s. 3084-3090
-
Tidskriftsartikel (refereegranskat)abstract
- Linkage analysis of F-2 crosses has led to identification of large numbers of quantitative trait loci (QTL) for complex diseases, but identification of the underlying genes has been more difficult. Reasons for this could be complications that arise from separation of interacting or neighboring loci. We made a partial advanced intercross (PAI) to characterize and fine-map linkage to collagen-induced arthritis in two chromosomal regions derived from the DBA/1 strain and crossed into the B10.Q strain: Cia7 on chromosome 7 and a locus on chromosome 15. Only Cia7 was detected by a previous F-2 cross. Linkage analysis of the PAI revealed a different linkage pattern than the F-2 cross, adding multiple loci and strong linkage to the previously unlinked chromosome 15 region. Subcongenic strains derived from animals in the PAI confirmed the loci and revealed additional subloci. In total, no less than seven new loci were identified. Several loci interacted and three loci were protective, thus partly balancing the effect of the disease-promoting loci. Our results indicate that F-2 crosses do not reveal the full complexity of identified QTLs, and that detection is more dependent on the genetic context of a QTL than the potential effect of the underlying gene.
|
|
| 2. |
- Ahlqvist, Emma, et al.
(författare)
-
High-resolution mapping of a complex disease, a model for rheumatoid arthritis, using heterogeneous stock mice
- 2011
-
Ingår i: Human Molecular Genetics. - Oxford : Oxford University Press. - 0964-6906 .- 1460-2083. ; 20:15, s. 3031-3041
-
Tidskriftsartikel (refereegranskat)abstract
- Resolving the genetic basis of complex diseases like rheumatoid arthritis will require knowledge of the corresponding diseases in experimental animals to enable translational functional studies. Mapping of quantitative trait loci in mouse models of arthritis, such as collagen-induced arthritis (CIA), using F(2) crosses has been successful, but can resolve loci only to large chromosomal regions. Using an inbred-outbred cross design, we identified and fine-mapped CIA loci on a genome-wide scale. Heterogeneous stock mice were first intercrossed with an inbred strain, B10.Q, to introduce an arthritis permitting MHCII haplotype. Homozygous H2(q) mice were then selected to set up an F(3) generation with fixed major histocompatibility complex that was used for arthritis experiments. We identified 26 loci, 18 of which are novel, controlling arthritis traits such as incidence of disease, severity and time of onset and fine-mapped a number of previously mapped loci. © The Author 2011. Published by Oxford University Press. All rights reserved.
|
|
| 3. |
- Ahlqvist, Emma, et al.
(författare)
-
The value of animal models in predicting genetic susceptibility to complex diseases such as rheumatoid arthritis.
- 2009
-
Ingår i: Arthritis Research and Therapy. - : Springer Science and Business Media LLC. - 1478-6362 .- 1478-6354. ; 11:3
-
Forskningsöversikt (refereegranskat)abstract
- ABSTRACT: For a long time, genetic studies of complex diseases were most successfully conducted in animal models. However, the field of genetics is now rapidly evolving, and human genetics has also started to produce strong candidate genes for complex diseases. This raises the question of how to continue gene-finding attempts in animals and how to use animal models to enhance our understanding of gene function. In this review we summarize the uses and advantages of animal studies in identification of disease susceptibility genes, focusing on rheumatoid arthritis. We are convinced that animal genetics will remain a valuable tool for the identification and investigation of pathways that lead to disease, well into the future.
|
|
| 4. |
- Amirahmadi, S. F., et al.
(författare)
-
Arthritogenic anti-type II collagen antibodies are pathogenic for cartilage-derived chondrocytes independent of inflammatory cells
- 2005
-
Ingår i: Arthritis and Rheumatism. - : Wiley. - 0004-3591 .- 1529-0131. ; 52:6, s. 1897-1906
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Some monoclonal antibodies (mAb) to type II collagen (CII) are arthritogenic upon passive transfer to mice. We undertook this study to investigate whether such mAb are pathogenic in the absence of mediators of inflammation. METHODS: The arthritogenic mAb CIIC1 and M2139, and the nonarthritogenic mAb CIIF4, each reactive with a distinct and well-defined conformational epitope on CII, were compared with control mAb GAD6. Bovine chondrocytes were cultured with one of the mAb, and on days 3, 6, and 9, antibody binding by chondrocytes and newly synthesized extracellular matrix (ECM) was examined by immunofluorescence, morphologic effects were studied by electron microscopy, and synthesis of matrix components was determined by metabolic labeling with (3)H-proline for collagen and (35)S-sulfate for proteoglycans. RESULTS: All 3 mAb to CII bound to the matrix. CIIC1 and M2139 adversely affected the cultures, whereas CIIF4 did not. CIIC1 caused disorganization of CII fibrils in the ECM without affecting chondrocyte morphology, and increased matrix synthesis. M2139 caused thickening and aggregation of CII fibrils in the ECM and abnormal chondrocyte morphology but matrix synthesis was unaffected. CONCLUSION: The unique arthritogenic capacity of particular anti-CII mAb upon passive transfer could be explained by their adverse, albeit differing, effects in primary cultures of chondrocytes. Such effects occur independent of inflammation mediators and are related to the epitope specificity of the mAb. Interference with the structural integrity of CII could precede, and even initiate, the inflammatory expression of disease.
|
|
| 5. |
- Andersson, Ida E, 1982-, et al.
(författare)
-
Design of glycopeptides used to investigate class II MHC binding and T-Cell responses associated with autoimmune arthritis
- 2011
-
Ingår i: PLOS ONE. - : Public Library of Science. - 1932-6203. ; 6:3, s. e17881-
-
Tidskriftsartikel (refereegranskat)abstract
- The glycopeptide fragment CII259–273 from type II collagen (CII) binds to the murine Aq and human DR4 class II Major Histocompatibility Complex (MHC II) proteins, which are associated with development of murine collagen-induced arthritis (CIA) and rheumatoid arthritis (RA), respectively. It has been shown that CII259–273 can be used in therapeutic vaccination of CIA. This glycopeptide also elicits responses from T-cells obtained from RA patients, which indicates that it has an important role in RA as well. We now present a methodology for studies of (glyco)peptide-receptor interactions based on a combination of structure-based virtual screening, ligand-based statistical molecular design and biological evaluations. This methodology included the design of a CII259–273 glycopeptide library in which two anchor positions crucial for binding in pockets of Aq and DR4 were varied. Synthesis and biological evaluation of the designed glycopeptides provided novel structure-activity relationship (SAR) understanding of binding to Aq and DR4. Glycopeptides that retained high affinities for these MHC II proteins and induced strong responses in panels of T-cell hybridomas were also identified. An analysis of all the responses revealed groups of glycopeptides with different response patterns that are of high interest for vaccination studies in CIA. Moreover, the SAR understanding obtained in this study provides a platform for the design of second-generation glycopeptides with tuned MHC affinities and T-cell responses.
|
|
| 6. |
- Andersson, Ida E., 1982-, et al.
(författare)
-
(E)-Alkene and Ethylene Isosteres Substantially Alter the Hydrogen-Bonding Network in Class II MHC Aq/Glycopeptide Complexes and Affect T-Cell Recognition
- 2011
-
Ingår i: Journal of the American Chemical Society. - : American Chemical Society. - 0002-7863 .- 1520-5126. ; 133:36, s. 14368-14378
-
Tidskriftsartikel (refereegranskat)abstract
- The structural basis for antigen presentation by class II major histocompatibility complex (MHC) proteins to CD4(+) T-cells is important for understanding and possibly treating autoimmune diseases. In the work described in this paper, (E)-alkene and ethylene amide-bond isosteres were used to investigate the effect of removing hydrogen-bonding possibilities from the CII259-270 glycopeptide, which is bound by the arthritis-associated murine A(q) class II MHC protein. The isostere-modified glycopeptides showed varying and unexpectedly large losses of A(q) binding that could be linked to the dynamics of the system. Molecular dynamics (MD) simulations revealed that the backbone of CII259-270 and the A(q) protein are able to form up to 11 hydrogen bonds, but fewer than this number are present at any one time. Most of the strong hydrogen-bond interactions were formed by the N-terminal part of the glycopeptide, i.e., in the region where the isosteric replacements were made. The structural dynamics also revealed that hydrogen bonds were strongly coupled to each other; the loss of one hydrogen-bond interaction had a profound effect on the entire hydrogen-bonding network. The A(q) binding data revealed that an ethylene isostere glycopeptide unexpectedly bound more strongly to A(q) than the corresponding (E)-alkene, which is in contrast to the trend observed for the other isosteres. Analysis of the MD trajectories revealed that the complex conformation of this ethylene isostere was structurally different and had an altered molecular interaction pattern compared to the other A(q)/glycopeptide complexes. The introduced amide-bond isosteres also affected the interactions of the glycopeptide/A(q) complexes with T-cell receptors. The dynamic variation of the patterns and strengths of the hydrogen-bond interactions in the class II MHC system is of critical importance for the class II MHC/peptide/TCR signaling system.
|
|
| 7. |
- Andersson, Ida E., 1982-, et al.
(författare)
-
Oxazole-modified glycopeptides that target arthritis-associated class II MHC Aq and DR4 proteins
- 2010
-
Ingår i: Organic and biomolecular chemistry. - : RSC Publishing. - 1477-0520 .- 1477-0539. ; 8:13, s. 2931-2940
-
Tidskriftsartikel (refereegranskat)abstract
- The glycopeptide CII259-273, a fragment from type II collagen (CII), can induce tolerance in mice susceptible to collagen-induced arthritis (CIA), which is a validated disease model for rheumatoid arthritis (RA). Here, we describe the design and synthesis of a small series of modified CII259-273 glycopeptides with oxazole heterocycles replacing three potentially labile peptide bonds. These glycopeptidomimetics were evaluated for binding to murine CIA-associated A(q) and human RA-associated DR4 class II major histocompatibility complex (MHC) proteins. The oxazole modifications drastically reduced or completely abolished binding to A(q). Two of the glycopeptidomimetics were, however, well tolerated in binding to DR4 and they also induced strong responses by one or two DR4-restricted T-cell hybridomas. This work contributes to the development of an altered glycopeptide for inducing immunological tolerance in CIA, with the long-term goal of developing a therapeutic vaccine for treatment of RA.
|
|
| 8. |
- Andersson, Ida E., 1982-, et al.
(författare)
-
Probing Molecular Interactions within Class II MHC A(q)/Glycopeptide/T-Cell Receptor Complexes Associated with Collagen-Induced Arthritis.
- 2007
-
Ingår i: Journal of Medicinal Chemistry. - : American Chemical Society (ACS). - 1520-4804 .- 0022-2623. ; 50:23, s. 5627-5643
-
Tidskriftsartikel (refereegranskat)abstract
- T cells obtained in a mouse model for rheumatoid arthritis are activated by a glycopeptide fragment from rat type II collagen (CII) bound to the class II major histocompatibility complex A(q) molecule. We report a comparative model of A(q) in complex with the glycopeptide CII260-267. This model was used in a structure-based design approach where the amide bond between Ala(261) and Gly(262) in the glycopeptide was selected for replacement with psi[COCH2], psi[CH2NH2+], and psi[(E)-CH=CH] isosteres. Ala-Gly isostere building blocks were then synthesized and introduced in CII260-267 and CII259-273 glycopeptides. The modified glycopeptides were evaluated for binding to the A(q) molecule, and the results were interpreted in view of the A(q)/glycopeptide model. Moreover, recognition by a panel of T-cell hybridomas revealed high sensitivity for the backbone modifications. These studies contribute to the understanding of the interactions in the ternary A(q)/glycopeptide/T-cell receptor complexes that activate T cells in autoimmune arthritis and suggest possibilities for new vaccination approaches.
|
|
| 9. |
- Andersson, Maria L.E., et al.
(författare)
-
Autoantibodies to Disease-Related Proteins in Joints as Novel Biomarkers for the Diagnosis of Rheumatoid Arthritis
- 2023
-
Ingår i: Arthritis & Rheumatology. - : Wiley. - 2326-5191 .- 2326-5205. ; 75:7, s. 1110-1119
-
Tidskriftsartikel (refereegranskat)abstract
- Objective. This study was undertaken to develop and characterize a multiplex immunoassay for detection of autoantibodies against peptides derived from proteins known to play a role in development of arthritis and that are also expressed in joints.Methods. We selected peptides from the human counterpart of proteins expressed in the joints, based on mouse models that showed these to be targeted by pathogenic or regulatory antibodies in vivo. Using bead-based flow immunoassays measuring IgG antibodies, we selected triple helical or cyclic peptides, containing the epitopes, to avoid collinear reactivity. We characterized the analytical performance of the immunoassay and then validated it in 3 independent rheumatoid arthritis (RA) cohorts (n = 2,110), Swedish age- and sex-matched healthy controls, and patients with osteoarthritis (OA), patients with psoriatic arthritis (PsA), and patients with systemic lupus erythematosus (SLE).Results. Screening assays showed 5 peptide antigens that discriminated RA patients from healthy controls with 99% specificity (95% confidence interval [CI] 98-100%). In our validation studies, we reproduced the discriminatory capacity of the autoantibodies in 2 other RA cohorts, showing that the autoantibodies had high discriminatory capacity for RA versus OA, PsA, and SLE. The novel biomarkers identified 22.5% (95% CI 19-26%) of early RA patients seronegative for anti-cyclic citrullinated peptide and rheumatoid factor. The usefulness of the biomarkers in identifying seronegative RA patients was confirmed in validation studies using 2 independent cohorts of RA patients and cohorts of patients with OA, PsA, and SLE.Conclusion. A multiplex immunoassay with peptides from disease-related proteins in joints was found to be useful for detection of specific autoantibodies in RA serum. Of note, this immunoassay had high discriminatory capacity for early seronegative RA.
|
|
| 10. |
- Andersson, Sofia E M, 1979, et al.
(författare)
-
Collagen epitope expression on B cells is sufficient to confer tolerance to collagen-induced arthritis
- 2016
-
Ingår i: Arthritis Research & Therapy. - : Springer Science and Business Media LLC. - 1478-6354 .- 1478-6362. ; 18
-
Tidskriftsartikel (refereegranskat)abstract
- Background: The mechanisms underlying tolerance induction and maintenance in autoimmune arthritis remain elusive. In a mouse model of rheumatoid arthritis, collagen type II (CII)-induced arthritis, we explore the contribution of B cells to antigen-specific tolerance. Methods: To generate expression of the CII-peptide specifically on B-cell major histocompatibility complex type II, lentiviral-based gene therapy including a B-cell-specific Igk promoter was used. Results: Presentation of the CII-peptide on B cells significantly reduced the frequency and severity of arthritis as well as the serum levels of CII -specific IgG antibodies. Further, both frequency and suppressive function of regulatory T cells were increased in tolerized mice. Adoptive transfer of regulatory T cells from tolerized mice to naive mice ameliorated the development of CII-induced arthritis. Conclusion: Our data suggest that endogenous presentation of the CII-peptide on B cells is one of the key contributors to arthritis tolerance induction and maintenance.
|
|
