In:
International Archives of Allergy and Immunology, S. Karger AG, Vol. 159, No. 2 ( 2012), p. 130-142
Abstract:
〈 b 〉 〈 i 〉 Background: 〈 /i 〉 〈 /b 〉 Phl p 5 is a major allergen of Timothy grass 〈 i 〉 (Phleum pratense). 〈 /i 〉 A recombinant native Phl p 5 has already been used in clinical trials of allergen-specific immunotherapy as a component of a cocktail of allergens. Recombinant hypoallergenic allergens should further improve the treatment by reducing the risk of anaphylactic reactions at an increased therapeutic dosage. Native Phl p 5 is formed by α-helical regions separated by regions containing prolines. In order to generate hypoallergenic mutants, we studied the effect of proline mutations in single and multiple regions. 〈 b 〉 〈 i 〉 Methods: 〈 /i 〉 〈 /b 〉 All mutants were analyzed by IgE inhibition assays and size exclusion chromatography with on-line mass determination. Selected mutants were additionally analyzed by field-flow fractionation, dynamic light scattering, circular dichroism spectroscopy, basophil activation and T-cell proliferation assays. 〈 b 〉 〈 i 〉 Results: 〈 /i 〉 〈 /b 〉 Variants lacking prolines in a single region were obtained as soluble monomers. Six of eight molecules showed a slightly reduced IgE-binding capacity. Mutants carrying proline deletions in multiple regions formed monomers, dimers or insoluble aggregates. The mutant MPV.7 with five proline deletions and a substitution of proline 211 to leucine is monomeric, shows a strongly diminished IgE binding and maintains T-cell reactivity. The hydrodynamic radius and the content of the α-helical structure of MPV.7 are well comparable with the wild-type allergen. 〈 b 〉 〈 i 〉 Conclusions: 〈 /i 〉 〈 /b 〉 The hypoallergenic Phl p 5 variant MPV.7 combines multiple proline deletions with a substitution of proline 211 to leucine and meets basic demands for a pharmaceutical application. MPV.7 is a promising candidate for grass pollen immunotherapy with a cocktail of recombinant hypoallergens.
Type of Medium:
Online Resource
ISSN:
1018-2438
,
1423-0097
Language:
English
Publisher:
S. Karger AG
Publication Date:
2012
detail.hit.zdb_id:
1108932-5
detail.hit.zdb_id:
1482722-0
