Tiotropium bromide attenuates respiratory syncytial virus replication in epithelial cells.
BACKGROUND
Respiratory syncytial virus (RSV) infection could be related to airway inflammation as well as exacerbation of chronic obstructive pulmonary disease (COPD). Tiotropium bromide decreases the frequency of exacerbation in patients with COPD; however, the mechanisms of tiotropium bromide to reduce the chances of exacerbation have not been defined. One potential mechanism could be that tiotropium bromide protects against RSV infection in epithelial cells.


OBJECTIVE
To examine whether tiotropium bromide affects RSV replication in HEp-2 cells.


METHODS
The supernatant titer of RSV was calculated by methylcellulose plaque assay after RSV innoculation. Intracellular RSV and ICAM-1 mRNA were measured by PCR. Syncytium formation was observed by light microscopy. Intracellular RSV fusion protein and RhoA protein were detected by Western blot analysis. Furthermore, RhoA activity, ICAM-1 expression and inflammatory cytokines in cultured supernatant were measured by binding assay, immunofluorescence staining and ELISA, respectively.


RESULTS
Tiotropium bromide decreased the supernatant titer of RSV, and it inhibited syncytium formation, RhoA activation and ICAM-1 expression. Moreover, it suppressed the production of IL-6 and IL-8 after RSV infection.


CONCLUSIONS
The antiviral effects of tiotropium bromide regarding RSV replication are partly due to inhibition of RhoA activity and ICAM-1 expression. Tiotropium bromide decreases RSV replication and may modulate airway inflammation by reducing the production of inflammatory cytokines.
Iesato
Ken
K
Department of Respirology, Graduate School of Medicine, Chiba University, Chiba, Japan.
Tatsumi
Koichiro
K
Saito
Kengo
K
Ogasawara
Takashi
T
Sakao
Seiichiro
S
Tada
Yuji
Y
Kasahara
Yasunori
Y
Kurosu
Katsushi
K
Tanabe
Nobuhiro
N
Takiguchi
Yuichi
Y
Kuriyama
Takayuki
T
Shirasawa
Hiroshi
H
D000998:Antiviral Agents / Q000494:pharmacology; D045744:Cell Line, Tumor; D018680:Cholinergic Antagonists / Q000494:pharmacology*; D004847:Epithelial Cells / Q000378:metabolism / Q000821:virology; D015726:Giant Cells / Q000187:drug effects; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism; D016209:Interleukin-8 / Q000378:metabolism; D012367:RNA, Viral / Q000032:analysis; D012136:Respiratory Syncytial Viruses / Q000187:drug effects* / Q000502:physiology; D012602:Scopolamine Derivatives / Q000494:pharmacology*; D000069447:Tiotropium Bromide; D014760:Viral Fusion Proteins / Q000032:analysis; D014779:Virus Replication / Q000187:drug effects*; D020742:rhoA GTP-Binding Protein / Q000037:antagonists & inhibitors
D000998:Antiviral Agents; D018680:Cholinergic Antagonists; D015850:Interleukin-6; D016209:Interleukin-8; D012367:RNA, Viral; D012602:Scopolamine Derivatives; D014760:Viral Fusion Proteins; D018799:Intercellular Adhesion Molecule-1; D020742:rhoA GTP-Binding Protein; D000069447:Tiotropium Bromide