Expression of CD27 and CD28 on γδ T cells from the peripheral blood of patients with allergic rhinitis

The costimulatory receptors CD27 and CD28 have pivotal and non-redundant roles in the activation and differentiation of gamma delta T-cells. However, the roles of CD27 and CD28 on gamma delta T-cells in allergic rhinitis (AR) have remained elusive. The aim of the present study was to investigate the expression of CD27 and CD28 on gamma delta T cells in patients with AR. Peripheral blood mononuclear cells from 14 patients with AR and 12 healthy subjects were isolated and analyzed by flow cytometry to determine the percentage of gamma delta T cells and regulatory T cells (Tregs), and the expression of IFN-gamma, IL-17A, CD27 and CD28 on gamma delta T cells. The correlations between the expression of CD27 and CD28, and the percentages of IFN-gamma (+) and IL-17A(+) gamma delta T-cell subsets and Tregs in AR were analyzed. It was observed that the percentages of gamma delta T cells, and the IL-17A(+), CD27(-)CD28(+) and CD27(-)CD28(-) gamma delta T-cell subsets were significantly increased, while the percentages of Tregs and IFN-gamma (+) and CD27(+)CD28(+) gamma delta T-cell subsets were significantly decreased in AR. Of note, the percentage of CD27(+)CD28(+) gamma delta T-cell subsets was positively correlated with that of the IFN-gamma (+) gamma delta T-cell subset and the percentage of the CD27(-)CD28(+) gamma delta T-cell subset was positively correlated with that of the IL-17A(+) gamma delta T-cell subset. Furthermore, the percentages of gamma delta T cells and the CD27(-)CD28(+) gamma delta T-cell subset were both negatively correlated with that of Tregs. Therefore, the results of the present study indicate that CD27 and CD28 may be the key signals for activation of different gamma delta T-cell subsets and may contribute to the immune regulatory function of gamma delta T cells in the peripheral blood of patients with AR.