Rhinovirus infects primary human airway fibroblasts and induces a neutrophil chemokine and a permeability factor

Abstract

The events linking rhinovirus (RV) infection to airway symptoms are poorly understood. The virus initially infects airway epithelium followed by a vigorous inflammatory response that may entail spread of RV from epithelium to other cells in the airway wall. However, RV has fastidious growth characteristics and to date reproductive infection of primary cells other than human airway epithelium has not been confirmed. Airway fibroblasts are adjacent to and in contact with epithelial cells, play a key role in innate immune responses, and may participate in the evolution of inflammation. To investigate fibroblast actions, we first determined whether RV could infect and replicate in primary culture human lung fibroblasts. RV serotype 16 (RV16) was used to infect fibroblasts grown from lung tissue, and virus infection with replication was demonstrated by a combination of techniques. RT-PCR was used to show an increase in RV transcription; confocal microscopy demonstrated colocalization of the replicative form of RV genome (double-stranded RNA) and RV16 proteins; infectious virus was also recovered from the culture supernatant of infected fibroblasts. Functional consequences of RV infection were next examined. RV infection of fibroblasts was followed by an increase in epithelial neutrophil-activating peptide-78 (ENA-78) mRNA and protein. The permeability factor vascular endothelial growth factor (VEGF) was also induced over a similar time course. These data suggest that interactions between RV and human fibroblasts are feasible, may coordinate neutrophil chemoattraction with enhanced vascular permeability and that fibroblasts may contribute to inflammatory responses following RV infections.

Contribution of Bronchial Fibroblasts to the Antiviral Response in Asthma

“…Our findings are consistent with the fact that diploid fibroblast cell lines are used for propagation of HRV and are more efficient than HeLa cells for recovery of HRVs from clinical isolates (18), further underlining their permissiveness for RV replication. However, our results contrast with a previous study in which lung fibroblasts were infected with RV at an MOI of 10, yet infection of only 5-15% of cells was observed (10). In a small study comparing fibroblasts from two normal and two asthmatic donors, we also observed that higher doses of RV16 were required for infection.…”

“…Although epithelial cells are the main target for HRV infection, several studies have indicated that HRV may be detected in the subepithelial layer by in situ hybridization (8,9) and that human lung fibroblasts are susceptible to HRV infection (10). Bronchial fibroblasts are part of the mesenchymal layer in the airway tissue and have the versatility to differentiate into other connective tissue families such as smooth muscle cells and myofibroblasts (11).…”

Chemokine (C-C Motif) Receptor 1 Is Required for Efficient Recruitment of Neutrophils during Respiratory Infection with Modified Vaccinia Virus Ankara

“…Macrophages and fibroblasts are potential targets for viral infection in the lung that may contribute to the development of local immune responses by production of inflammatory mediators (31)(32)(33), making them potentially important sentinel cells. To assess the infectivity of these cell types, monolayers of MLFs and BMDM were infected with a recombinant MVA-GFP at different MOIs and measured after 16 h by flow cytometry.…”

Rhinovirus 16 2A Protease Affects Nuclear Localization of 3CD during Infection

“…At 18 h posttransfection (see above), cells were either lysed in RIPA buffer and subjected to Western blot analysis to confirm protein expression or fixed with 4% formaldehyde in PBS (17). Cells were incubated with Hoechst 33342 (ThermoFisher Scientific) diluted in PBS for 10 min, washed twice in PBS, and mounted using Fluorescence mounting medium (Dako).…”