Cell Penetrating Peptide Derived from Human Eosinophil Cationic Protein Decreases Airway Allergic Inflammation

Lin-Shien Fu,Jaw-Ji Tsai,Yu-Rou Wu,Shun-Lung Fang,Margaret Dah-Tsyr Chang,Yee-Jun Chen,Heng-Kuei Lin,Ting-Yu Chen

doi:10.1038/s41598-017-12390-8

Abstract

Cell penetrating peptide derived from human eosinophil cationic protein (CPPecp) is a 10-amino-acid peptide containing a core heparan sulfate (HS)-binding motif of human eosinophil cationic protein (ECP). It binds and penetrates bronchial epithelial cells without cytotoxic effects. Here we investigated airway-protective effects of CPPecp in BEAS-2B cell line and mite-induced airway allergic inflammation in BALB/c mice. In BEAS-2B cell, CPPecp decreases ECP-induced eotaxin mRNA expression. CPPecp also decreases eotaxin secretion and p-STAT6 activation induced by ECP, as well as by IL-4. In vivo studies showed CPPecp decreased mite-induced airway inflammation in terms of eosinophil and neutrophil count in broncho-alveolar lavage fluid, peri-bronchiolar and alveolar pathology scores, cytokine production in lung protein extract including interleukin (IL)-5, IL-13, IL-17A/F, eotaxin; and pause enhancement from methacholine stimulation. CPPecp treated groups also showed lower serum mite-specific IgE level. In this study, we have demonstrated the in vitro and in vivo anti-asthma effects of CPPecp.

Highlights

B cells, T-helper 2 (Th2) cells and Th2 related mediators play key roles in inflammatory responses in allergic asthma
The mite treated group (mIT) group had a higher IgE level (103 ng/ml) than did the cIN + mIT, mIT + cIN, and cIN + mIT + cIN groups on day 23, approximately 2.5 to 3.6 fold higher than the CPPecp treated groups. This pilot study suggests a protective effect of CPPecp on airway allergic inflammation in Der p-treated BALB/c mice
eosinophil cationic protein (ECP) and CPPecp both bind to heparan sulfate proteoglycans (HSPGs) on cell surface and have cell penetrating characters, as we have demonstrated previously[7,8,9]

Summary

Introduction

B cells, T-helper 2 (Th2) cells and Th2 related mediators play key roles in inflammatory responses in allergic asthma. Among which interleukin (IL)−4 is a cytokine regulating development of allergic inflammation It is associated with induction of Th2 differentiation as well as allergen specific IgE secretion by B cells[3]. Models have demonstrated that ECP preferentially targets tracheo-epithelial cells in rat mainly due to abundant HSPG expression on cell surface[10], and radiolabeled ECP is able to image HS expression to predict allergic lung inflammation in an asthma mouse model[11]. Cytotoxicity of ECP is severely reduced in HS-deficient cell lines, in vivo targeting of ECP to lung tissues is significantly diminished in the presence of heparanase, implying critical roles of HSPGs in ECP function. GAGs are anchored on cell surface, as a signaling co-receptor, binding to multiple ligands, and promoting receptor-ligand interactions that mediate cell growth, motility, and immune response[12]. As a consequence of binding to a receptor, HS can recruit GAG-binding natural receptor ligands, for example, IL-413, IL-514, IL-615,16 and IL-1317 to promote downstream bioactivities[18]

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Conclusion