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- Gafvelin, G, et al.
(författare)
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Cytokine and antibody responses in birch-pollen-allergic patients treated with genetically modified derivatives of the major birch pollen allergen Bet v 1
- 2005
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Ingår i: International Archives of Allergy and Immunology. - : S. Karger AG. - 1018-2438 .- 1423-0097. ; 138:1, s. 59-66
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Tidskriftsartikel (refereegranskat)abstract
- Background: Recently, recombinant hypoallergenic derivatives of the major birch pollen allergen, Bet v 1, were used to treat birch-pollen-allergic patients in a double-blind, placebo-controlled, multi-centre immunotherapy study. The aim of this study was to evaluate the effects of vaccination with aluminium-hydroxide-adsorbed recombinant Bet v 1 derivatives versus placebo on T-cell, cytokine and antibody responses in a subgroup of patients. Methods: Blood was drawn from patients of the Swedish centre (n=27; rBet v 1 fragments: n=10; rBet v 1 trimer: n=8, and placebo-aluminium hydroxide: n=9) before the start and after completion of the treatment. PBMC were stimulated with rBet v 1 and analysed for cytokine (IL-4, IL-5, IL-10, IL-12, IL-13 and IFN-gamma)-secreting cells by ELISpot. Bet v 1-specific antibody levels in serum (IgG(1-4), IgE and IgA) were measured by ELISA. Skin prick tests with defined Bet v 1 concentrations were performed before and 10-11 months after the beginning of the study. Results: Bet v 1-specific IgG levels, consisting of IgG 1, IgG 2 and IgG 4, were significantly increased after treatment with recombinant allergen derivatives. Treatment with rBet v 1 trimer led to a significant (p<0.05) reduction of Bet v 1-reactive IL-5- and IL-13-producing cells, reflecting a reduced Th2 response. In addition, a decreased number of Bet v 1-reactive IL-4 producing (p=0.07) and an increase of IL-12-producing (p=0.06) cells was noted in the trimer-treated patients. In contrast to placebo, active treatment resulted in significantly reduced immediate-type skin reactions to Bet v 1 even 10-11 months after treatment. Conclusion: Vaccination with recombinant hypoallergenic Bet v 1 derivatives induces a Bet v 1-specific IgG response and leads to reduced skin reactivity in allergic patients. A reduction of Bet v 1-specific Th2 responses was observed in trimer-treated patients, which may reflect the intrinsic property of this allergen derivative. Copyright (C) 2005 S. Karger AG, Basel.
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| 4. |
- Kaiser, L, et al.
(författare)
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Structural characterization of the tetrameric form of the major cat allergen Fel d 1
- 2007
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Ingår i: Journal of Molecular Biology. - : Elsevier BV. - 0022-2836 .- 1089-8638. ; 370:4, s. 714-727
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Tidskriftsartikel (refereegranskat)abstract
- Felis domesticus allergen 1(Fel d 1) is a 35 kDa tetrameric glycoprotein formed by two heterodimers which elicits IgE responses in 95% of patients with allergy to cat. We have previously established in vitro conditions for the appropriate folding of recombinant Fel d 1 using a direct linkage of chain 1 to chain 2 (construct Fel d 1 (1+2)) and chain 2 to chain 1 (construct Fel d 1 (2+1)). Although the crystal structure of Fel d 1 (2+1) revealed a striking structural similarity to that of uteroglobin, a steroid-inducible cytokine-like molecule with anti-inflammatory and immunomodulatory properties, no functional tetrameric form of Fel d 1 could be identified. Here we present the crystal structure of the Fel d 1 (1+2) tetramer at 1.6 A resolution. Interestingly, the crystal structure of tetrameric Fel d 1 reveals two different calcium-binding sites. Symmetrically positioned on each side of the Fel d 1 tetramer, the external Ca(2+)-binding sites correspond to a putative Ca(2+)-binding site previously suggested for uteroglobin. The second Ca(2+)-binding site lies within the dimerization interface, stabilizing the formation of the Fel d 1 tetramer, and inducing important local conformational changes that directly govern the shape of two water-filled cavities. The crystal structure suggests a potential portal for an unknown ligand. Alternatively, the two cavities could be used by the allergen as a conditional inner space allowing for the spatial rearrangement of centrally localized side-chains, such as Asp130, without altering the overall fold of the molecule. The striking structural similarity of the major cat allergen to uteroglobin, coupled to the identification in the present study of a common Ca(2+)-binding site, let us speculate that Fel d 1 could provoke an allergic response through the modulation of phospholipase A2, by sequestering Ca ions in a similar manner as previously suggested for uteroglobin.
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| 5. |
- Neimert-Andersson, T., et al.
(författare)
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Carbohydrate-based particles reduce allergic inflammation in a mouse model for cat allergy
- 2008
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Ingår i: Allergy. European Journal of Allergy and Clinical Immunology. - : John Wiley & Sons. - 0105-4538 .- 1398-9995. ; 63:5, s. 518-526
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Tidskriftsartikel (refereegranskat)abstract
- Background: Allergen-specific immunotherapy (ASIT) is the only treatment of allergic disease that gives long-lasting relief of symptoms. However, concerns for safety and efficiency have highlighted the need for improvement of the therapy. We have previously suggested carbohydrate-based particles (CBPs) as a novel adjuvant and allergen carrier for ASIT. Our aim of this study was to evaluate the therapeutic potential of CBPs in ASIT, employing a mouse model for cat allergy. Methods: BALB/c mice were subcutaneously immunized with the recombinant (r) cat allergen Fel d 1 followed by intranasal challenge with cat dander extract (CDE). The sensitized mice were therapeutically treated with rFel d 1 covalently coupled to CBPs (CBP-rFel d 1). Airway hyper-reactivity (AHR), infiltration of leucocytes in bronchoalveolar lavage (BAL) fluid, allergen-specific serum immunoglobulin levels and in vitro splenocyte responses were evaluated. Results: Mice treated with CBP-rFel d 1 showed reduced features of allergic inflammation. They responded with (i) significantly decreased AHR and infiltration of eosinophils in BAL fluid after CDE challenge, (ii) the serum level of rFel d 1-specific IgE was reduced and the level of IgG(2)a was more pronounced after CBP-rFel d 1 treatment, and (iii) there was also a tendency of decreased allergen-specific cellular response. Conclusions: Carbohydrate-based particles are effective tools as adjuvant and allergen carriers for use in ASIT and constitutes a promising strategy to improve allergy treatment.
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| 7. |
- Ronnmark, J., et al.
(författare)
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Human immunoglobulin A (IgA)-specific ligands from combinatorial engineering of protein A
- 2002
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Ingår i: European Journal of Biochemistry. - : Wiley. - 0014-2956 .- 1432-1033. ; 269:11, s. 2647-2655
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Tidskriftsartikel (refereegranskat)abstract
- Affinity reagents capable of selective recognition of the different human immunoglobulin isotypes are important detection and purification tools in biotechnology. Here we describe the development and characterization of affinity proteins (affibodies) showing selective binding to human IgA. From protein libraries constructed by combinatorial mutagenesis of a 58-amino-acid, three-helix bundle domain derived from the IgG-binding staphylococcal protein A, variants showing IgA binding were selected by using phage display technology and IgA monoclonal antibodies (myeloma) as target molecules. Characterization of selected clones by biosensor technology showed that five out of eight investigated affibody variants were capable of IgA binding, with dissociation constants (K (d) ) in the range between 0.5 and 3 mum. One variant (Z(IgA1) ) showing the strongest binding affinity was further analyzed, and showed that human IgA subclasses (IgA(1) and IgA(2) ) as well as secretory IgA were recognized with similar efficiencies. No detectable cross-reactivity towards human IgG, IgM, IgD or IgE was observed. The potential use of the Z(IgA1) affibody as a ligand in affinity chromatography applications was first demonstrated by selective recovery of IgA protein from a spiked Escherichia coli total cell lysate, using an affinity column containing a divalent head-to-tail Z(IgA1) affibody dimer construct as a ligand. In addition, efficient affinity recovery of IgA from unconditioned human plasma was also demonstrated.
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