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| 2. |
- Forsberg-Nilsson, Karin, et al.
(författare)
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The fibroblast mitogenic activity resleased from human basophilic cell line KU812 is separated from tryptase and PDGF expression
- 1996
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Ingår i: Scandinavian Journal of Immunology. - 0300-9475 .- 1365-3083. ; 44:3, s. 267-272
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Tidskriftsartikel (refereegranskat)abstract
- The human leukaemia cell line KU812 has previously been used to study basophil differentiation. In this study the authors analysed the capacity of KU812 to produce the mast cell proteinase tryptase and to synthesize factor(s) mitogenic for fibroblasts. KU812 cells were treated with tetradecanoyl-phorbol-13-acetate (TPA), conditioned medium from the human T-cell line Mo (Mo-CM), or cultured under serum free conditions. After 4 days the cells were analysed for cell growth, differentiation, content of tryptase, and secretion of fibroblast mitogenic activity. Mo-CM and serum starvation increased the expression while TPA treatment down-regulated the expression of Fc epsilon RI-alpha chain. An increase in tryptase content in cell extracts was detected after 4 days of culture in serum-free medium or in the presence of Mo-CM. KU812 conditioned media was found to have a baseline expression of mitogenic activity on normal human foreskin fibroblasts that was increased after serum starvation or after treatment with TPA. Mast cell-derived tryptase has previously been reported to be mitogenic for fibroblasts, but in this study the expression of tryptase did not correlate with the expression of fibroblast mitogenic activity in KU812 cells. Furthermore, affinity-purified lung tryptase did not show any mitogenic activity. Platelet-derived growth factor was also excluded. Although the factor(s) from KU812 cells stimulating fibroblast proliferation have not been identified, our results indicate that basophils may be potential producers of growth factors inducing fibroblast proliferation.
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| 3. |
- Nilsson, U R, et al.
(författare)
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Modification of the complement binding properties of polystyrene : effects of end-point heparin attachment.
- 1993
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Ingår i: Scandinavian Journal of Immunology. - 0300-9475 .- 1365-3083. ; 37:3, s. 349-354
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Tidskriftsartikel (refereegranskat)abstract
- In recent years, conjugation of heparin to biomaterials has been shown to improve its biocompatibility. The purpose of the present work was to compare complement activation and binding of C3 to unmodified and heparin-treated polystyrene surfaces of microtitre plates. When polystyrene was incubated with human serum, C3 was deposited on the surface by both adsorption and binding dependent on activation of the classical (CPW) and alternative (APW) pathways. After end-point attachment of heparin, significant C3 deposition, although at reduced levels, occurred only by CPW-mediated mechanisms, while adsorption and APW-mediated binding were strongly reduced. Generally, the modified surface bound lower amounts of protein, e.g. serum albumin and IgG, than the unmodified. By contrast, it had increased affinity for C1q which leads to binding of C1 and activation of complement via the CPW. Nevertheless, the net effect of the surface modification on the complement reaction was an overall reduction of C3 binding due to obliteration of APW. This can be related to an enhanced factor H/I-dependent down-regulation of C3b and to the lowered protein-adsorbing property of the surface, both of which have inhibitory effects on APW and on the C3 shunt-dependent activation of the complement system.
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| 4. |
- Siegbahn, Agneta, et al.
(författare)
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The chemokinetic inhibitory factor derived from chronic lymphocytic leukaemia cells : Partial purification and characterization of a new lymphokine
- 1986
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Ingår i: Scandinavian Journal of Immunology. - 0300-9475 .- 1365-3083. ; 23:1, s. 15-23
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Tidskriftsartikel (refereegranskat)abstract
- We have recently described a heat-labile and cell-directed neutrophil migration inhibitory activity that is present in serum from patients with chronic lymphocytic leukaemia (CLL). The inhibitory activity is produced and secreted by CLL cells in vitro. In the present study the inhibitory activity was partially purified from short-term cultures of monoclonal leukaemic B-CLL cells. On gel filtration the calculated molecular weight was apparently 30,000. By anion exchange chromatography, the inhibitory factor was recovered in the fractions that eluted with 0.3 mol/l NaCl. The active material applied to preparative agarose gel electrophoresis migrated towards the anode. The inhibitory factor was totally destroyed by trypsin. In addition it bound to concanavalin A-Sepharose. These properties indicate that the inhibitory factor is a glycoprotein. Antibodies against the isolated inhibitory factor were raised in rabbits. CLL serum was separated by means of gel filtration and the inhibitory activity was recovered in the pool with a molecular weight of approximately 30,000. The activity was completely neutralized by the antibodies raised against the CLL-cell-derived inhibitor, indicating the similarity between this and the serum-derived inhibitor. We have shown the existence of a new lymphokine, derived from B-CLL cells, in serum from patients with CLL.
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