BACKGROUND: Programmed cell death-1 (PD-1) is a negative regulator of T-cell responses. Expression of PD-1 and its ligands PD-L1 and PD-L2 in chronic rhinosinusitis with nasal polyps (CRSwNP) is poorly studied.
METHODS: Expression of PD-1, PD-L1, PD-L2, TGF-β, IL-5, and IL-10 mRNA was measured by real-time quantitative PCR on tissue homogenates of patients with CRSwNP (n = 21) and healthy controls (n = 21) and on primary epithelial cells. Disease severity was scored using the Lund-Mackay scores of maxillofacial computed tomography (CT) scans. Expression of PD-1 and PD-L1/L2 was evaluated at the cellular and tissue levels (n = 6) by flow cytometry and immunohistochemistry.
RESULTS: Programmed cell death-1 mRNA expression was increased in tissue homogenates from patients with CRSwNP compared with controls, irrespective of the atopy status. Importantly, expression of PD-1 correlated with the total CT scan scores (r = 0.5, P = 0.02). Additionally, a significant association was found between PD-1 mRNA and expression of IL-5 mRNA in control nasal tissue (r = 0.95, P < 0.0001) and in CRSwNP (r = 0.63, P = 0.002). PD-1 was expressed on different subsets of T cells and CD11b- dendritic cells. Both PD-1 and its ligands were expressed on primary epithelial cells from control nasal tissue and nasal polyp tissue.
CONCLUSIONS: Higher PD-1 expression was found in CRSwNP than in nasal tissue from controls. This was associated with disease severity and tissue IL-5 expression but unrelated to the patients' atopy status.
Bibliographical note© 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
- Case-Control Studies
- Chronic Disease
- Dendritic Cells/metabolism
- Middle Aged
- Nasal Polyps/complications
- Programmed Cell Death 1 Receptor/analysis
- RNA, Messenger/analysis
- Severity of Illness Index