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Glucocorticosteroids enhance replication of respiratory viruses: effect of adjuvant interferon

View Article: PubMed Central - PubMed

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.

No MeSH data available.


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GCS pre-treatment of primary human airway cells enhances viral replication; an effect blunted by IFN.PBEC or PAF were treated with GCS for 24 hrs, washed and then infected with IAV (left panels) or RV (right panels). (A) Levels of infectious virus in cell supernatants were determined by plaque assay (IAV) or titration (RV). Data represent the mean ± SD from triplicate samples and are representative of a minimum of cultures from 3 independent donors. Infectious virus in cell supernatants significantly increased with GCS treatment, * p < 0.05, *** p < 0.001, Student's t-test. (B) At 1 hr following IAV or RV infection, monolayers were stimulated with 250 IU/ml of human IFNα2, IFNβ or IFNλ1 and levels of infectious virus in cell supernatants were determined at the time points indicated. The detection limit of the assay is indicated as a dotted line. Data represent the mean ± SD from triplicate samples and are representative of a minimum of cultures from 3 independent donors. Infectious virus in cell supernatants significantly reduced by addition of IFN in both GCS treated and mock-treated infected cells, * p < 0.05, ** p < 0.01, *** p < 0.001, one-way ANOVA and Tukey's post-test.
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f3: GCS pre-treatment of primary human airway cells enhances viral replication; an effect blunted by IFN.PBEC or PAF were treated with GCS for 24 hrs, washed and then infected with IAV (left panels) or RV (right panels). (A) Levels of infectious virus in cell supernatants were determined by plaque assay (IAV) or titration (RV). Data represent the mean ± SD from triplicate samples and are representative of a minimum of cultures from 3 independent donors. Infectious virus in cell supernatants significantly increased with GCS treatment, * p < 0.05, *** p < 0.001, Student's t-test. (B) At 1 hr following IAV or RV infection, monolayers were stimulated with 250 IU/ml of human IFNα2, IFNβ or IFNλ1 and levels of infectious virus in cell supernatants were determined at the time points indicated. The detection limit of the assay is indicated as a dotted line. Data represent the mean ± SD from triplicate samples and are representative of a minimum of cultures from 3 independent donors. Infectious virus in cell supernatants significantly reduced by addition of IFN in both GCS treated and mock-treated infected cells, * p < 0.05, ** p < 0.01, *** p < 0.001, one-way ANOVA and Tukey's post-test.

Mentions: Treatment of PBEC and PAF with GCS for 24 hrs prior to IAV infection significantly increased the levels of infectious virus in cell supernatants 24, 48 and 72 hrs following infection (Fig. 3A, left panels). In agreement with previous reports1825, GCS pre-treatment of PBEC did not alter RV replication at 24 or 48 hrs following infection but levels of infectious virus in supernatants from PBEC were significantly increased by GCS at 72 hrs. In addition, we did not observe any significant differences in viral titers 24 hrs following RV infection of PAF (Fig. 3A, right panel), as described by Val Ly et al15. We did, however, detect elevated viral replication in GCS pre-treated PAF at 48 and 72 hrs following RV infection. In addition, the GCS-mediated elevation of infectious RV in cell supernatants correlated with significant increases in viral RNA isolated from PBEC and PAF (Supplementary Fig. S1). No substantial virus amplification was detected between 2 and 24 hrs following IAV or RV infection of PAM (data not shown). Immunofluorescent staining for viral proteins indicated that GCS pre-treatment of PBEC, PAF or PAM did not significantly alter the proportion of cells infected at 8 hrs following RV or IAV infection (Supplementary Table S1). This finding indicates that the observed effects on viral titers were due to enhanced virus replication overall rather than being the result of greater numbers of cells primarily infected.


Glucocorticosteroids enhance replication of respiratory viruses: effect of adjuvant interferon
GCS pre-treatment of primary human airway cells enhances viral replication; an effect blunted by IFN.PBEC or PAF were treated with GCS for 24 hrs, washed and then infected with IAV (left panels) or RV (right panels). (A) Levels of infectious virus in cell supernatants were determined by plaque assay (IAV) or titration (RV). Data represent the mean ± SD from triplicate samples and are representative of a minimum of cultures from 3 independent donors. Infectious virus in cell supernatants significantly increased with GCS treatment, * p < 0.05, *** p < 0.001, Student's t-test. (B) At 1 hr following IAV or RV infection, monolayers were stimulated with 250 IU/ml of human IFNα2, IFNβ or IFNλ1 and levels of infectious virus in cell supernatants were determined at the time points indicated. The detection limit of the assay is indicated as a dotted line. Data represent the mean ± SD from triplicate samples and are representative of a minimum of cultures from 3 independent donors. Infectious virus in cell supernatants significantly reduced by addition of IFN in both GCS treated and mock-treated infected cells, * p < 0.05, ** p < 0.01, *** p < 0.001, one-way ANOVA and Tukey's post-test.
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f3: GCS pre-treatment of primary human airway cells enhances viral replication; an effect blunted by IFN.PBEC or PAF were treated with GCS for 24 hrs, washed and then infected with IAV (left panels) or RV (right panels). (A) Levels of infectious virus in cell supernatants were determined by plaque assay (IAV) or titration (RV). Data represent the mean ± SD from triplicate samples and are representative of a minimum of cultures from 3 independent donors. Infectious virus in cell supernatants significantly increased with GCS treatment, * p < 0.05, *** p < 0.001, Student's t-test. (B) At 1 hr following IAV or RV infection, monolayers were stimulated with 250 IU/ml of human IFNα2, IFNβ or IFNλ1 and levels of infectious virus in cell supernatants were determined at the time points indicated. The detection limit of the assay is indicated as a dotted line. Data represent the mean ± SD from triplicate samples and are representative of a minimum of cultures from 3 independent donors. Infectious virus in cell supernatants significantly reduced by addition of IFN in both GCS treated and mock-treated infected cells, * p < 0.05, ** p < 0.01, *** p < 0.001, one-way ANOVA and Tukey's post-test.
Mentions: Treatment of PBEC and PAF with GCS for 24 hrs prior to IAV infection significantly increased the levels of infectious virus in cell supernatants 24, 48 and 72 hrs following infection (Fig. 3A, left panels). In agreement with previous reports1825, GCS pre-treatment of PBEC did not alter RV replication at 24 or 48 hrs following infection but levels of infectious virus in supernatants from PBEC were significantly increased by GCS at 72 hrs. In addition, we did not observe any significant differences in viral titers 24 hrs following RV infection of PAF (Fig. 3A, right panel), as described by Val Ly et al15. We did, however, detect elevated viral replication in GCS pre-treated PAF at 48 and 72 hrs following RV infection. In addition, the GCS-mediated elevation of infectious RV in cell supernatants correlated with significant increases in viral RNA isolated from PBEC and PAF (Supplementary Fig. S1). No substantial virus amplification was detected between 2 and 24 hrs following IAV or RV infection of PAM (data not shown). Immunofluorescent staining for viral proteins indicated that GCS pre-treatment of PBEC, PAF or PAM did not significantly alter the proportion of cells infected at 8 hrs following RV or IAV infection (Supplementary Table S1). This finding indicates that the observed effects on viral titers were due to enhanced virus replication overall rather than being the result of greater numbers of cells primarily infected.

View Article: PubMed Central - PubMed

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.

No MeSH data available.


Related in: MedlinePlus