Art v 1
Description
IgE Epitopes
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Primary IgE Binding: Localized to the N-terminal defensin domain .
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Conformational Epitopes: A newly identified C-terminal domain epitope, critical for IgE binding in folded Art v 1, was mapped using humanized mice and patient sera .
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Recombinant vs. Native: Native Art v 1 exhibits higher IgE reactivity than recombinant forms due to glycosylation differences .
T-Cell Responses
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Immunodominant Epitope: A single T-cell epitope (recognized by >80% of patients) is HLA-DR restricted and linked to Th2 responses .
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Therapeutic Potential: The epitope’s homogeneity makes Art v 1 a candidate for peptide immunotherapy .
T-Cell Response Comparison
| Parameter | Natural Art v 1 | Recombinant Art v 1 |
|---|---|---|
| Cross-reactivity | 85% TCC cross-react | Limited |
| Epitope Recognition | Single dominant | Single dominant |
| HLA Restriction | HLA-DR | HLA-DR |
| Source |
Cross-Reactivity and Allergenic Relationships
Art v 1 exhibits cross-reactivity with allergens from botanically related plants:
| Cross-Reactive Source | Allergen Homolog | Basis of Cross-Reactivity |
|---|---|---|
| Ragweed (Ambrosia) | Amb a 4 | Defensin-like domain similarity |
| Sunflower (Helianthus) | Hel a 1/2 | Shared polypeptide/carbohydrate structures |
| Chamomile | Art v 1-like | Homologous glycoprotein domains |
This cross-reactivity is attributed to conserved structural motifs and carbohydrate determinants (e.g., xylose/fucose) .
Diagnostic Utility
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Sensitivity: >95% of mugwort-allergic patients exhibit sIgE reactivity to Art v 1 .
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Recombinant Forms: Used in diagnostic assays but require higher allergen doses due to reduced IgE binding compared to native forms .
Therapeutic Advances
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Immunotherapy Targets: The immunodominant T-cell epitope and conformational IgE epitopes are candidates for hypoallergenic vaccines .
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Blocking Strategies: IgG antibodies raised against non-IgE-reactive peptides (e.g., C-terminal domain) may neutralize allergic responses .
Key Research Findings
Product Specs
Defensin-like protein 1.
Product Science Overview
Art v 1 is the major allergen found in the pollen of mugwort (Artemisia vulgaris), a common weed in the Compositae family. Mugwort pollen is a significant cause of allergic reactions, particularly in late summer and autumn. Art v 1 is a glycoprotein with a defensin-like domain and a hydroxyproline-rich domain .
Art v 1 is a modular protein composed of an N-terminal cysteine-rich domain, similar to plant defensins, and a C-terminal proline-rich region. The proline-rich region contains several (Ser/Ala)(Pro)2-4 repeats, and some proline residues are post-translationally modified by hydroxylation and O-glycosylation . These modifications are crucial for the protein’s allergenic properties, as they influence IgE antibody binding .
Art v 1 is a significant allergen for mugwort-allergic patients, with sensitization rates varying by geographical location. In Europe, sensitization rates range from 10% to 15%, while in some regions, up to 95% of mugwort-allergic patients are sensitized to Art v 1 . The allergen can trigger respiratory symptoms such as allergic rhino-conjunctivitis and asthma, as well as pollen-food allergy symptoms like oral allergy syndrome, urticaria, angioedema, and anaphylaxis .
