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 γδ T-cells. However, the roles of CD27 and CD28 on γδ 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 γδ 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 γδ T cells and regulatory T cells (Tregs), and the expression of IFN-γ, IL-17A, CD27 and CD28 on γδ T cells. The correlations between the expression of CD27 and CD28, and the percentages of IFN-γ(+) and IL-17A(+) γδ T-cell subsets and Tregs in AR were analyzed. It was observed that the percentages of γδ T cells, and the IL-17A(+), CD27(-)CD28(+) and CD27(-)CD28(-) γδ T-cell subsets were significantly increased, while the percentages of Tregs and IFN-γ(+) and CD27(+)CD28(+) γδ T-cell subsets were significantly decreased in AR. Of note, the percentage of CD27(+)CD28(+) γδ T-cell subsets was positively correlated with that of the IFN-γ(+) γδ T-cell subset and the percentage of the CD27(-)CD28(+) γδ T-cell subset was positively correlated with that of the IL-17A(+) γδ T-cell subset. Furthermore, the percentages of γδ T cells and the CD27(-)CD28(+) γδ 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 γδ T-cell subsets and may contribute to the immune regulatory function of γδ T cells in the peripheral blood of patients with AR.