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Specific V beta T cell subsets mediate the immediate hypersensitivity response to ragweed allergen
H Renz1, J Saloga, K L Bradley
1Department of Pediatrics, National Jewish Center for Immunology and Respiratory Medicine, Denver, CO 80206.
Journal of Immunology (Baltimore, Md. : 1950)
|August 15, 1993
Summary
Ragweed sensitization in mice triggers specific T cell responses, leading to allergic reactions and increased airway responsiveness. V beta 8.2 T cells are crucial for stimulating IgE/IgG1 production and airway hyperresponsiveness.
Area of Science:
- Immunology
- Allergy Research
- Respiratory Medicine
Background:
- Allergen sensitization, such as to ragweed (RW), can lead to allergic diseases characterized by IgE antibody production and airway hyperresponsiveness.
- T and B cell subsets play critical roles in orchestrating immune responses to allergens.
Purpose of the Study:
- To investigate the role of specific T cell populations, particularly V beta-expressing T cells, in mediating immune responses and airway hyperresponsiveness following ragweed sensitization.
- To elucidate the mechanisms by which T cells influence IgE and IgG1 production and contribute to allergic airway inflammation.
Main Methods:
- BALB/c mice were sensitized to ragweed (RW) via ultrasonic nebulization.
- Immune responses were assessed by measuring anti-RW antibody titers (IgE, IgG1) and performing skin testing for immediate cutaneous hypersensitivity.
- Airway responsiveness was evaluated using electrical field stimulation of tracheal smooth muscle preparations.
- T cell populations expressing specific V beta chains were analyzed in lymphoid tissues and spleen.
- Co-culture experiments were performed to assess the ability of T cell subsets to stimulate B cell antibody production.
Main Results:
- Ragweed sensitization induced significant IgE and IgG1 anti-RW antibody responses and type I allergic reactions.
- Increased airway responsiveness was observed in sensitized mice, correlated with mononuclear cell infiltration in the airways.
- Specific T cell populations, including V beta 8.1+, V beta 8.2+, and V beta 13+ in local lymph nodes, and V beta 8.1+, V beta 8.2+, V beta 8.3+, V beta 9+, and V beta 14+ in the spleen, were expanded.
- V beta 8.2 T cells were identified as key players, stimulating both IgE and IgG1 production in the presence of RW.
- Transfer of V beta 8.2 T cells from sensitized mice to naive recipients induced allergen-specific IgE and IgG1 responses and increased airway responsiveness.
Conclusions:
- Specific V beta-expressing T cell subpopulations, particularly V beta 8.2 T cells, are pivotal in driving IgE/IgG1 production and allergic airway hyperresponsiveness.
- These findings highlight the critical role of T cell subsets in the pathogenesis of allergic airway inflammation and provide targets for therapeutic interventions.