Deep sequencing of primary human lung epithelial cells challenged with H5N1 influenza virus reveals a proviral role for CEACAM1

Christopher J. Cowled,John Stambas,Cheng-Hon Yap,Siying Ye

doi:10.1038/s41598-018-33605-6

Abstract

Current prophylactic and therapeutic strategies targeting human influenza viruses include vaccines and antivirals. Given variable rates of vaccine efficacy and antiviral resistance, alternative strategies are urgently required to improve disease outcomes. Here we describe the use of HiSeq deep sequencing to analyze host gene expression in primary human alveolar epithelial type II cells infected with highly pathogenic avian influenza H5N1 virus. At 24 hours post-infection, 623 host genes were significantly upregulated, including the cell adhesion molecule CEACAM1. H5N1 virus infection stimulated significantly higher CEACAM1 protein expression when compared to influenza A PR8 (H1N1) virus, suggesting a key role for CEACAM1 in influenza virus pathogenicity. Furthermore, silencing of endogenous CEACAM1 resulted in reduced levels of proinflammatory cytokine/chemokine production, as well as reduced levels of virus replication following H5N1 infection. Our study provides evidence for the involvement of CEACAM1 in a clinically relevant model of H5N1 infection and may assist in the development of host-oriented antiviral strategies.

Highlights

Influenza viruses cause acute and highly contagious seasonal respiratory disease in all age groups
There is emerging evidence to suggest that CEACAM1 is involved in host immunity as enhanced expression in lymphocytes was detected in pregnant women infected with cytomegalovirus[18] and in cervical tissue isolated from patients with papillomavirus infection[19]
Three experimental groups were included in the HiSeq analysis of H5N1 infection in the presence or absence of the reactive oxygen species (ROS) inhibitor, apocynin: (i) uninfected cells treated with 1% DMSO (ND), (ii) H5N1-infected cells treated with 1% DMSO (HD) and (iii) H5N1-infected cells treated with 1 mM apocynin dissolved in DMSO (HA)

Summary

Introduction

Influenza viruses cause acute and highly contagious seasonal respiratory disease in all age groups. Human host gene expression following HPAI H5N1 virus (A/Chicken/ Vietnam/0008/04) infection of primary ATII cells was analyzed using Illumina HiSeq deep sequencing. Several criteria were considered when choosing a “hit” for further study These included: (1) Novelty; has this gene been studied before in the context of influenza virus infection/pathogenesis? CEACAM1 homophilic or heterophilic interactions and ITIM phosphorylation are critical for many biological processes, including regulation of lymphocyte function, immunosurveillance, cell growth and differentiation[25,26] and neutrophil activation and adhesion to target cells during inflammatory responses[27]. MRG1 blocked CEACAM1 homophilic interactions that inhibit T cell effector function, enhancing the killing of CEACAM1+ melanoma cells by T cells[28] This highlights a potential intervention pathway that can be exploited in other disease processes, including virus infection. Ceacam1-knockout mice are available for further in vivo infection studies

Methods

Results

Conclusion