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A human monoclonal IgE antibody defines a highly allergenic fragment of the major timothy grass pollen allergen, Phl p 5: molecular, immunological, and structural characterization of the epitope-containing domain.
- Source :
-
Journal of immunology (Baltimore, Md. : 1950) [J Immunol] 2000 Oct 01; Vol. 165 (7), pp. 3849-59. - Publication Year :
- 2000
-
Abstract
- Almost 90% of grass pollen-allergic patients are sensitized against group 5 grass pollen allergens. We isolated a monoclonal human IgE Fab out of a combinatorial library prepared from lymphocytes of a grass pollen-allergic patient and studied its interaction with group 5 allergens. The IgE Fab cross-reacted with group 5A isoallergens from several grass and corn species. By allergen gene fragmentation we mapped the binding site of the IgE Fab to a 11.2-kDa N-terminal fragment of the major timothy grass pollen allergen Phl p 5A. The IgE Fab-defined Phl p 5A fragment was expressed in Escherichia coli and purified to homogeneity. Circular dichroism analysis revealed that the rPhl p 5A domain, as well as complete rPhl p 5A, assumed a folded conformation consisting predominantly of an alpha helical secondary structure, and exhibited a remarkable refolding capacity. It reacted with serum IgE from 76% of grass pollen-allergic patients and revealed an extremely high allergenic activity in basophil histamine release as well as skin test experiments. Thus, the rPhl p 5A domain represents an important allergen domain containing several IgE epitopes in a configuration optimal for efficient effector cell activation. We suggest the rPhl p 5A fragment and the corresponding IgE Fab as paradigmatic tools to explore the structural requirements for highly efficient effector cell activation and, perhaps later, for the development of generally applicable allergen-specific therapy strategies.
- Subjects :
- Allergens immunology
Allergens metabolism
Amino Acid Sequence
Antibodies, Monoclonal genetics
Antibodies, Monoclonal metabolism
Antibody Specificity genetics
Basophils metabolism
Binding Sites, Antibody genetics
Binding Sites, Antibody immunology
Circular Dichroism
Cross Reactions
Epitope Mapping
Epitopes immunology
Epitopes metabolism
Histamine Release immunology
Humans
Hypersensitivity, Immediate immunology
Immunoglobulin E genetics
Immunoglobulin E metabolism
Immunoglobulin Fab Fragments genetics
Immunoglobulin Fab Fragments metabolism
Molecular Sequence Data
Peptide Fragments chemistry
Peptide Fragments genetics
Peptide Fragments immunology
Peptide Fragments isolation & purification
Peptide Mapping
Plant Proteins genetics
Plant Proteins immunology
Plant Proteins isolation & purification
Poaceae chemistry
Pollen immunology
Protein Structure, Tertiary genetics
Recombinant Proteins chemistry
Recombinant Proteins immunology
Recombinant Proteins isolation & purification
Recombinant Proteins metabolism
Structure-Activity Relationship
Zea mays chemistry
Zea mays immunology
Allergens chemistry
Antibodies, Monoclonal chemistry
Epitopes chemistry
Immunoglobulin E chemistry
Immunoglobulin Fab Fragments chemistry
Plant Proteins chemistry
Poaceae immunology
Pollen chemistry
Subjects
Details
- Language :
- English
- ISSN :
- 0022-1767
- Volume :
- 165
- Issue :
- 7
- Database :
- MEDLINE
- Journal :
- Journal of immunology (Baltimore, Md. : 1950)
- Publication Type :
- Academic Journal
- Accession number :
- 11034391
- Full Text :
- https://doi.org/10.4049/jimmunol.165.7.3849