PD-1 expression correlates with disease severity and IL-5 in Chronic Rhinosinusitis with Nasal Polyps

Abstract

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 RT-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 maxillo-facial CT scans. PD-1 and PD-L1/L2 expression were evaluated at the cellular and tissue level (n=6) by flow cytometry and immunohistochemistry.

Results

PD-1 mRNA expression was increased in tissue homogenates from patients with CRSwNP compared to controls, irrespectively 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.

This article is protected by copyright. All rights reserved.

http://ift.tt/2k1olqZ