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- Lind, Thomas, et al.
(author)
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Purification of an insect derived recombinant human ADAMTS-1 reveals novel gelatin (type I collagen) degrading activities.
- 2006
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In: Molecular and Cellular Biochemistry. - : Springer Science and Business Media LLC. - 0300-8177 .- 1573-4919. ; 281:1-2, s. 95-102
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Journal article (peer-reviewed)abstract
- ADAMTS-1 (A Disintegrin And Metalloprotease with ThromboSpondin repeats) is a member of a family of secreted proteolytic enzymes with a complex modular structure. These enzymes are characterised by an N-terminal metalloproteinase domain, a disintegrin-like domain and a carboxyl terminal region containing variable numbers of a repeat sequence with homology to thrombospondin-1. The expression of the gene for ADAMTS-1 has been associated with inflammation, ovulation, angiogenesis, cellular proliferation and bone formation. ADAMTS-1 can proteolytically process large proteoglycans indicating a potential role in extracellular matrix turnover. In this study, we have tested ADAMTS-1 activity in gelatin zymogram assays. Since previous data demonstrate that ADAMTS-1 is a matrix metalloproteinase (MMP) substrate and is highly unstable in conditioned medium from eukaryotic cell types, we created an insect cell line expressing human ADAMTS-1. We isolated an epitope tagged full-length recombinant ADAMTS-1 from serum free insect cell conditioned medium. The purified protein had aggrecanase activity and appears as two major bands on the silver stained SDS-PAGE corresponding well to a pro-domain on form of 115 kDa and a pro-domain off form of 90 kDa. Using denatured type I collagen in zymographic analysis we demonstrate that ADAMTS-1 has a previously unreported gelatinolytic activity. Also, we notice that processing of its C-terminal region by an apparently autocatalytic process reveals a 27 kDa species with gelatinolytic activity. Furthermore, we show that MMP2 but not MMP13 remove ADAMTS-1 specific gelatin zymopraphic zones.
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| 2. |
- von Delwig, Alexei, et al.
(author)
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T cell responses to a non-glycosylated epitope predominate in type II collagen-immunised HLA-DRB1*0101 transgenic mice
- 2007
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In: Annals of the Rheumatic Diseases. - : BMJ. - 1468-2060 .- 0003-4967. ; 66:5, s. 599-604
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Journal article (peer-reviewed)abstract
- Aim: To study collagen-induced arthritis in human leucocyte antigen (HLA)-DR1 transgenic mice lacking endogenous major histocompatibility complex class II molecules (MHC-II) and to determine T cell specificity against the arthritogenic CII259-273 epitope of type II collagen either unmodified or post-translationally glycosylated at Lys(264). Methods: Arthritis was induced by immunisation with human type II collagen in complete Freund's adjuvant and measured by footpad swelling, clinical score and histology. T cell responses were assessed by proliferation of spleen and lymph node cells and in antigen presentation assays, using T cell hybridomas specific for the glycosylated and non-glycosylated CII259-273 epitope. Results: The incidence of arthritis was 50% in DR1-transgenic mice lacking endogenous MHC-II molecules. Recall T cell responses in draining lymph nodes and spleen were consistently greater against the nonglycosylated epitope than to the glycosylated CII259-273. Most of the T cell hybridomas generated from CII-immunised mice recognised the non-glycosylated CII epitope and this form of the epitope was also presented with 100-fold higher efficiency and 1 h faster kinetics by both macrophages and dendritic cells. Conclusion: This study shows that T cell responses to the non-glycosylated epitope of heterologous ( human) CII are dominant in HLA-DR1 transgenic mice lacking MHC-II, which could contribute to the pathogenicity of autoimmune arthritis.
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