Human γδ T cells modulate the mite allergen-specific T-helper type 2-skewed immunity

Backgournd gamma delta T cells have been described as one of immune regulators in patients with infection, malignancy, and allergy. Objective To elucidate the ability of gamma delta T cells as an allergen immunotherapy candidate, the effectiveness of human gamma delta T cells in allergen-specific T-helper type 2 (Th2)-type T cells was evaluated in vitro. Methods House dust mite-specific Th2-type T cell clones, Bacillus Calmette-Guerin (BCG)-specific Th1-type T cell clones, and gamma delta T cell lines were established from the peripheral blood mononuclear cells of two patients with allergic rhinitis. The effectiveness of gamma delta T cells and BCG-specific Th1-type T cell clones in the modulation of allergen-specific Th2 cells in terms of their cytokine productions was evaluated. Results In response to cognate antigens, the gamma delta T cell lines demonstrated a proliferation and production of IFN-gamma that exceeded that of BCG-specific Th1-type T cell clones (mean stimulation index: 14.5 vs. 2.8, mean IFN-gamma: 130.5 vs. 10.0 pg/mL). When the gamma delta T cell lines and mite-allergen-specific Th2 clones were co-cultured with each other, only the levels of IL-4 (mean, -87%) decreased, but not the levels of IL-5 and IL-13, with an increasing concentration of gamma delta T cell antigen and IFN-gamma production (mean, +730%). Conclusion These results demonstrated that gamma delta T cells derived from allergic patients might thus have a partial ability to modulate allergen-specific Th2-skewed immunity.