| 1. |
- Dzhambazov, Balik, et al.
(författare)
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The major T cell epitope on type II collagen is glycosylated in normal cartilage but modified by arthritis in both rats and humans
- 2005
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Ingår i: European Journal of Immunology. - : Wiley. - 1521-4141 .- 0014-2980. ; 35:2, s. 357-366
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Tidskriftsartikel (refereegranskat)abstract
- Type II collagen (CII) is a target for autoreactive T cells in both rheumatoid arthritis and the murine model collagen-induced arthritis. The determinant core of CII has been identified as CII260-270, and the alteration of this T cell epitope by posttranslational modifications is known to be critical for development of arthritis in mice. Using CII-specific T cell hybridomas we have now shown that the immunodominant T cell epitope in the normal (healthy) human and rat joint cartilage is O-glycosylated at the critical T cell receptor recognition position 264 with a mono- or di-saccharide attached to a hydroxylysine. In contrast, in the arthritic human and rat joint cartilage there are both glycosylated and non-glycosylated CII forms. Glycosylated CII from normal cartilage could not be recognized by T cells reactive to peptides having only lysine or hydroxylysine at position 264, showing that antigen-presenting cells could not degrade the O-linked carbohydrate. Thus, the variable forms of the glycosylated epitope are determined by the structures present in cartilage, and these vary during the disease course. We conclude that the chondrocyte determines the structures presented to the immune system and that these structures are different in normal versus arthritic states.
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| 2. |
- Holmdahl, Meirav, et al.
(författare)
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Cysteine proteases in Langerhans cells limits presentation of cartilage derived type II collagen for autoreactive T cells.
- 2004
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Ingår i: International Immunology. - : Oxford University Press (OUP). - 1460-2377. ; 16:5, s. 717-726
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Tidskriftsartikel (refereegranskat)abstract
- Development of type-II collagen (CII)-induced arthritis (CIA) is dependent on activation of CII-reactive T cells. Dendritic cells (DCs) are believed to play a crucial role in antigen-specific priming of T cells but it is still unclear how the CII-reactive T cells are primed since Langerhans cells (LCs) are poor antigen-presenting cells for CII. In the present study we show that LCs, treated with cysteine protease inhibitors, are able to process and present CII to T-cell hybridomas specific for the immune-dominant glycosylated 259–270 peptide bound to the MHC class II molecule Aq. Interestingly, the self (mouse) CII peptide could also now be efficiently presented. The poor presentation by LCs is a peptide-specific effect, since both bovine CII (bCII) (presenting a different peptide on H-2r) and ovalbumin could be efficiently presented, and blockage of cysteine proteases did not enhance antigen presentation. The enhanced CII-presentation by cysteine protease inhibition is seen mainly in LCs and not in antigen-primed B cells or macrophages. B cell and macrophage presentation of CII occur even without protease inhibition and are only to a minor extent influenced by cysteine protease inhibition. These data suggest that a LC deficiency in processing of the immune-dominant CII epitope in both CIA and RA may limit the exposure of this self-antigen to T cells, but that presentation can be overcome by modulation of the peptide proteolysis during CII processing.
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| 3. |
- Holmdahl, Meirav, et al.
(författare)
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Primed B cells present type-II collagen to T cells.
- 2002
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Ingår i: Scandinavian Journal of Immunology. - : Wiley. - 1365-3083 .- 0300-9475. ; 55:4, s. 382-389
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Tidskriftsartikel (refereegranskat)abstract
- Development of type-II collagen (CII)-induced arthritis (CIA) is dependent on a T-cell mediated activation of autoreactive B cells. However, it is still unclear if B cells can present CII to T cells. To investigate the role of B cells as antigen-presenting cells (APCs) for CII, we purified B cells from lymph nodes of immunized and nonimmunized mice. These B cells were used as APC for antigen-specific T-cell hybridomas. B cells from naïve mice did present native, triple-helical, CII (nCII) but also ovalbumin (OVA) and denatured CII (dCII) to antigen-specific T-cell hybridomas. In addition, B cells primed with nCII or OVA, but not dCII, activated the antigen-specific T-cell hybridomas two to three times better than naïve B cells. We conclude that antigen-primed B cells have the capacity to process and present CII to primed T cells, and antigen-primed antigen-specific B cells are more efficient as APC than naïve B cells. We further conclude that B cells have the potential to play an important role as APC in the development of CIA.
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| 4. |
- Holmdahl, Meirav, et al.
(författare)
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Structure-Immune Response Relationships of Hapten-Modified Collagen II Peptides in a T-Cell Model of Allergic Contact Dermatitis.
- 2008
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Ingår i: Chemical Research in Toxicology. - : American Chemical Society (ACS). - 1520-5010 .- 0893-228X. ; 21, s. 1514-1523
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Tidskriftsartikel (refereegranskat)abstract
- Allergic contact dermatitis (ACD) is mediated by T cells that specifically recognize hapten-modified peptides. T cells are known to recognize antigens as short processed peptides bound to major histocompatibility complex (MHC) molecules on the surface of antigen-presenting cells (APC). It has previously been demonstrated that T cells can specifically recognize carbohydrates on the lysine at position 264 of the immunodominant (256-273) sequence from type II collagen (CII) and that such recognition is critical for the development of arthritis in mice and may play a role in rheumatoid arthritis in humans. In the present study, we have used this approach in modeling ACD, but instead of the carbohydrate, the strong sensitizer 2,4-dinitrofluorobenzene (DNFB) is bound to the epsilon-amine of the lysine at position 264. Specific T-cell hybridomas of this antigenic peptide, with dinitrophenyl (Dnp) on the epsilon-amine of lysine at position 264 (CIILysDnp 3), were established from mice immunized with CIILysDnp 3. In an immune response assay, these T-cell hybridomas were tested with a series of new synthetic hapten-modified peptides, all chemically identical except for the stereochemimistry ( d, l) and the length of the position-264 amino acid side chain bonding the hapten. The T-cell hybridomas recognized the CIILysDnp 3 peptide used for immunization; interestingly, they also recognized the CII peptide with a one-carbon-longer side chain (homolysine), CIIhLysDnp 6, and CIIAlaPipDnp 11, having a ring structure analogous to that of lysine with the same number of carbons in the bonding chain as in the CIILysDnp 3 peptide used for immunization. Dnp-modified CII peptides with a shorter bonding chain produced no immune response. These data demonstrate that the T-cell recognition of the Dnp-modified peptides is highly specific and moreover dependent on the length of the amino acid side chain that bonds the Dnp.
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| 5. |
- Khmaladze, Ia, et al.
(författare)
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Mannan induces ROS-regulated, IL-17A-dependent psoriasis arthritis-like disease in mice
- 2014
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - Washington, DC : National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 111:35, s. E3669-E3678
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Tidskriftsartikel (refereegranskat)abstract
- Psoriasis (Ps) and psoriasis arthritis (PsA) are poorly understood common diseases, induced by unknown environmental factors, affecting skin and articular joints. A single i.p. exposure to mannan from Saccharomyces cerevisiae induced an acute inflammation in inbred mouse strains resembling human Ps and PsA-like disease, whereas multiple injections induced a relapsing disease. Exacerbation of disease severity was observed in mice deficient for generation of reactive oxygen species (ROS). Interestingly, restoration of ROS production, specifically in macrophages, ameliorated both skin and joint disease. Neutralization of IL-17A, mainly produced by gammadelta T cells, completely blocked disease symptoms. Furthermore, mice depleted of granulocytes were resistant to disease development. In contrast, certain acute inflammatory mediators (C5, Fcgamma receptor III, mast cells, and histamine) and adaptive immune players (alphabeta T and B cells) were redundant in disease induction. Hence, we propose that mannan-induced activation of macrophages leads to TNF-alpha secretion and stimulation of local gammadelta T cells secreting IL-17A. The combined action of activated macrophages and IL-17A produced in situ drives neutrophil infiltration in the epidermis and dermis of the skin, leading to disease manifestations. Thus, our finding suggests a new mechanism triggered by exposure to exogenous microbial components, such as mannan, that can induce and exacerbate Ps and PsA.
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| 6. |
- Dzhambazov, Balik, et al.
(författare)
-
The major T cell epitope on type II collagen is glycosylated in normal cartilage but modified by arthritis in both rats and humans
- 2005
-
Ingår i: EUROPEAN JOURNAL OF IMMUNOLOGY. - : Wiley. - 0014-2980 .- 1521-4141. ; 35:2, s. 357-66
-
Tidskriftsartikel (refereegranskat)abstract
- Type II collagen (CII) is a target for autoreactive T cells in both rheumatoid arthritis and the murine model collagen-induced arthritis. The determinant core of CII has been identified as CII260-270, and the alteration of this T cell epitope by posttranslational modifications is known to be critical for development of arthritis in mice. Using CII-specific T cell hybridomas we have now shown that the immunodominant T cell epitope in the normal (healthy) human and rat joint cartilage is O-glycosylated at the critical T cell receptor recognition position 264 with a mono- or di-saccharide attached to a hydroxylysine. In contrast, in the arthritic human and rat joint cartilage there are both glycosylated and non-glycosylated CII forms. Glycosylated CII from normal cartilage could not be recognized by T cells reactive to peptides having only lysine or hydroxylysine at position 264, showing that antigen-presenting cells could not degrade the O-linked carbohydrate. Thus, the variable forms of the glycosylated epitope are determined by the structures present in cartilage, and these vary during the disease course. We conclude that the chondrocyte determines the structures presented to the immune system and that these structures are different in normal versus arthritic states.
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| 7. |
- Holmdahl, Meirav
(författare)
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Dendritic cell presentation of type II collagen
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Type II collagen (CII) is the main protein component of cartilage and immune recognition of CII plays a critical role for the development of collagen induced arthritis (CIA), a widely used animal model for rheumatoid arthritis (RA). Antigen presentation is an important requirement for the immune response, the more efficient presentation of the antigen the better tolerance will be induced and thereby protect against arthritis. Out of different professional antigen presenting cells (APCs), Langerhans cells (LCs), a subtype of dendritic cells, have been shown to poorly present CII compared to other antigens tested, but also compared to other APCs like B cells and macrophages. The inability to present CII is an exception from the rule that dendritic cells (DCs) are efficient in antigen presentation and subsequently in priming of naive T cells. This incompetence could however be overcome by treating with cysteine protease inhibitors, inhibiting certain cathepsins important for antigen degradation of the CII peptide in endosomes. Cystatin C, a natural occurring inhibitor of cathepsin S, is expressed in immature DCs. Cystatin C deficient mice were back-crossed into arthritis susceptible B10.Q mouse strain, surprisingly, with no difference in CII presentation between different genotypes and APCs in vitro. However, upon CII immunization, homozygous cystatin C deficient mice had a more severe arthritis ans disease incidence compared to wild-type littermates. The anti-CII antibody titers and delayed type hypersensitivity response (DTH) were also increased in the cystatin C deficient mice compared to the wild-type controls. The interpretation of our data favours antigen presentation being the targe cells for cystatin C activity. The present observation that the NOD.Q strain, which is resistant ti CIA in spite of expressing the arthritis susceptibel MHC class II H2-Aq allele, in fact have LCs which do present CII provide possibility to genetically dissect the phenomena. The major loci located on chromosome 2 and 13 were found to control LC presentation of CII. Of these two loci ine of them strongly correlated with CIA, an observation confirmed with the help of the Cia2 congenic mouse. Thus within this limited region there are one or several genes that affect LC CII presentaion and possibly these could be same as the genes controlling CIA.
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