Objectives: The major aims of this study were to characterize the varieties of T-cell infiltrates in tissue collected from patients with chronic rhinosinusitis with nasal polyps (CRSwNP), analyze the cytokine profiles of these infiltrating T cells, and determine whether infiltrating T lymphocytes are specific for superantigens (SAGs).
Methods: Anterior ethmoid sinus mucosa and polyp tissue were collected from 23 patients with CRSwNP, and control anterior ethmoid sinus mucosa were obtained from 20 patients without CRS. Infiltrating cells were isolated from tissue samples and analyzed using flow cytometry, enzyme-linked immunosorbent assay, reverse transcriptase-polymerase chain reaction, and in vitro T-lymphocyte stimulation with Staphylococcus aureus.
Results: The mean total numbers and proportions of CD3+, CD4+, and CD8+ T cells were significantly higher in the mucosa and polyp tissue of patients with CRSwNP than in the control group. Most infiltrating T cells in patients with CRSwNP were activated CD45RO+ memory T cells. Furthermore, interferon-γ (IFN-γ) expression was significantly higher than interleukin (IL)-10 and IL-4 expression in infiltrating T cells isolated from both the mucosa and the polyp tissue. IFN-γ also showed significantly greater increases in expression compared to IL-4 and IL-10 when isolated T cells were stimulated with SAGs in vitro.
Conclusion: IFN-γ-producing T cells could play an important role in CRSwNP when sinonasal chronic inflammation is induced by SAGs.