Dataset Information

Glucocorticosteroids enhance replication of respiratory viruses: effect of adjuvant interferon.

ABSTRACT: Glucocorticosteroids (GCS) are used on a daily basis to reduce airway inflammation in asthma and chronic obstructive pulmonary disease (COPD). This treatment is usually escalated during acute disease exacerbations, events often associated with virus infections. We examined the impact of GCS on anti-viral defences and virus replication and assessed supplementary interferon (IFN) treatment. Here, we report that treatment of primary human airway cells in vitro with GCS prior to rhinovirus (RV) or influenza A virus (IAV) infection significantly reduces the expression of innate anti-viral genes and increases viral replication. Mice given intranasal treatment with GCS prior to IAV infection developed more severe disease associated with amplified virus replication and elevated inflammation in the airways. Adjuvant IFN treatment markedly reduced GCS-amplified infections in human airway cells and in mouse lung. This study demonstrates that GCS cause an extrinsic compromise in anti-viral defences, enhancing respiratory virus infections and provides a rationale for adjuvant IFN treatment.

SUBMITTER: Thomas BJ

PROVIDER: S-EPMC5384105 | biostudies-literature | 2014 Nov

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Glucocorticosteroids enhance replication of respiratory viruses: effect of adjuvant interferon.

Thomas Belinda J BJ Porritt Rebecca A RA Hertzog Paul J PJ Bardin Philip G PG Tate Michelle D MD

Scientific reports 20141124

Glucocorticosteroids (GCS) are used on a daily basis to reduce airway inflammation in asthma and chronic obstructive pulmonary disease (COPD). This treatment is usually escalated during acute disease exacerbations, events often associated with virus infections. We examined the impact of GCS on anti-viral defences and virus replication and assessed supplementary interferon (IFN) treatment. Here, we report that treatment of primary human airway cells in vitro with GCS prior to rhinovirus (RV) or i ...[more]

PMID: 25417801

Similar Datasets

Project description:Cellular intrinsic immunity, mediated by the expression of an array of interferon-stimulated antiviral genes, is a vital part of host defense. We have previously used a bioinformatic screen to identify two interferon-stimulated genes (ISG) with poorly characterized function, interferon-induced protein 44 (IFI44) and interferon-induced protein 44-like (IFI44L), as potentially being important in respiratory syncytial virus (RSV) infection. Using overexpression systems, CRISPR-Cas9-mediated knockout, and a knockout mouse model, we investigated the antiviral capability of these genes in the control of RSV replication. Overexpression of IFI44 or IFI44L was sufficient to restrict RSV infection at an early time postinfection. Knocking out these genes in mammalian airway epithelial cells increased levels of infection. Both genes express antiproliferative factors that have no effect on RSV attachment but reduce RSV replication in a minigenome assay. The loss of Ifi44 was associated with a more severe infection phenotype in a mouse model of infection. These studies demonstrate a function for IFI44 and IFI44L in controlling RSV infection.IMPORTANCE RSV infects all children under 2 years of age, but only a subset of children get severe disease. We hypothesize that susceptibility to severe RSV necessitating hospitalization in children without predefined risk factors is, in part, mediated at the antiviral gene level. However, there is a large array of antiviral genes, particularly in the ISG family, the mechanism of which is poorly understood. Having previously identified IFI44 and IFI44L as possible genes of interest in a bioinformatic screen, we dissected the function of these two genes in the control of RSV. Through a range of overexpression and knockout studies, we show that the genes are antiviral and antiproliferative. This study is important because IFI44 and IFI44L are upregulated after a wide range of viral infections, and IFI44L can serve as a diagnostic biomarker of viral infection.

Project description:The acute antiviral response is mediated by a family of interferon-stimulated genes (ISGs), providing cell-intrinsic immunity. Mutations in genes encoding these proteins are often associated with increased susceptibility to viral infections. One family of ISGs with antiviral function is the interferon-inducible transmembrane proteins (IFITMs), of which IFITM3 has been studied extensively. In contrast, IFITM1 has not been studied in detail. Since IFITM1 can localize to the plasma membrane, we investigated its function with a range of enveloped viruses thought to infect cells by fusion with the plasma membrane. Overexpression of IFITM1 prevented infection by a number of Paramyxoviridae and Pneumoviridae, including respiratory syncytial virus (RSV), mumps virus, and human metapneumovirus (HMPV). IFITM1 also restricted infection with an enveloped DNA virus that can enter via the plasma membrane, herpes simplex virus 1 (HSV-1). To test the importance of plasma membrane localization for IFITM1 function, we identified blocks of amino acids in the conserved intracellular loop (CIL) domain that altered the subcellular localization of the protein and reduced antiviral activity. By screening reported data sets, 12 rare nonsynonymous single nucleotide polymorphisms (SNPs) were identified in human IFITM1, some of which are in the CIL domain. Using an Ifitm1-/- mouse, we show that RSV infection was more severe, thereby extending the range of viruses restricted in vivo by IFITM proteins and suggesting overall that IFITM1 is broadly antiviral and that this antiviral function is associated with cell surface localization.IMPORTANCE Host susceptibility to viral infection is multifactorial, but early control of viruses not previously encountered is predominantly mediated by the interferon-stimulated gene (ISG) family. There are upwards of 300 of these genes, the majority of which do not have a clearly defined function or mechanism of action. The cellular location of these proteins may have an important effect on their function. One ISG located at the plasma membrane is interferon-inducible transmembrane protein 1 (IFITM1). Here we demonstrate that IFITM1 can inhibit infection with a range of viruses that enter via the plasma membrane. Mutant IFITM1 proteins that were unable to localize to the plasma membrane did not restrict viral infection. We also observed for the first time that IFITM1 plays a role in vivo, and Ifitm1-/- mice were more susceptible to viral lung infection. These data contribute to our understanding of how ISGs prevent viral infections.

Dataset Information

Glucocorticosteroids enhance replication of respiratory viruses: effect of adjuvant interferon.

Publications

Glucocorticosteroids enhance replication of respiratory viruses: effect of adjuvant interferon.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure