Abstract
Background
Among atopic individuals, levels of allergen-specific IgG antibodies have been inversely associated with the degree of allergen sensitization. Additionally, allergen-specific IgG antibodies are markedly increased by allergen injection immunotherapy. These observations have led to proposals that allergen-specific IgG antibodies might have protective properties in atopic individuals.
Objective
We hypothesized that after grass pollen immunotherapy, these antibodies disrupt IgE-dependent allergen processing by antigen-presenting cells.
Methods
We have developed a novel flow cytometric assay based on detection of allergen-IgE binding to the low-affinity IgE receptor on B cells to examine the blocking effects of sera collected from 18 patients who participated in a double-blind, controlled trial of grass pollen immunotherapy for 1 year.
Results
In all 10 patients who received active therapy, there was induction of activity that inhibited allergen-IgE binding to B cells (P = .02, vs placebo subjects), as well as subsequent allergen presentation to T cells. This activity copurified with IgG and was allergen specific, because sera taken from patients treated with grass pollen immunotherapy but who were also birch pollen sensitive did not inhibit IgE-birch pollen allergen binding to B cells.
Conclusion
We conclude that allergen-specific IgG antibodies induced by immunotherapy can disrupt formation of allergen-IgE complexes that bind to antigen-presenting cells and facilitate allergen presentation.
Among atopic individuals, levels of allergen-specific IgG antibodies have been inversely associated with the degree of allergen sensitization. Additionally, allergen-specific IgG antibodies are markedly increased by allergen injection immunotherapy. These observations have led to proposals that allergen-specific IgG antibodies might have protective properties in atopic individuals.
Objective
We hypothesized that after grass pollen immunotherapy, these antibodies disrupt IgE-dependent allergen processing by antigen-presenting cells.
Methods
We have developed a novel flow cytometric assay based on detection of allergen-IgE binding to the low-affinity IgE receptor on B cells to examine the blocking effects of sera collected from 18 patients who participated in a double-blind, controlled trial of grass pollen immunotherapy for 1 year.
Results
In all 10 patients who received active therapy, there was induction of activity that inhibited allergen-IgE binding to B cells (P = .02, vs placebo subjects), as well as subsequent allergen presentation to T cells. This activity copurified with IgG and was allergen specific, because sera taken from patients treated with grass pollen immunotherapy but who were also birch pollen sensitive did not inhibit IgE-birch pollen allergen binding to B cells.
Conclusion
We conclude that allergen-specific IgG antibodies induced by immunotherapy can disrupt formation of allergen-IgE complexes that bind to antigen-presenting cells and facilitate allergen presentation.
| Original language | English |
|---|---|
| Pages (from-to) | 915-922 |
| Number of pages | 8 |
| Journal | Journal of Allergy and Clinical Immunology |
| Volume | 112 |
| Issue number | 5 |
| DOIs | |
| Publication status | Published - Nov 2003 |
Keywords
- Antigen Presentation
- Humans
- Immunotherapy
- B-Lymphocytes
- Pollen
- Receptors, IgE
- Hypersensitivity
- Allergens
- Immunoglobulin E
- Poaceae
- Adult
- Immunoglobulin G
- Middle Aged
- Time Factors
- Female
- Male
