Limits...
Phylogenetically distinct equine influenza viruses show different tropism for the swine respiratory tract.

Patrono LV, Bonfante F, Zanardello C, Terregino C, Capua I, Murcia PR - J. Gen. Virol. (2015)

Bottom Line: Previous work suggests that mutations acquired during EIV evolution might have played a role in CIV emergence.We show that phylogenetically distinct EIVs display different infection phenotypes along the pig respiratory tract, but not in cell lines.Our results suggest that EIV displays a dynamic host range along its evolutionary history, supporting the view that evolutionary processes play important roles in host range and tropism and also underscoring the utility of using explant cultures to study influenza pathogenesis.

View Article: PubMed Central - PubMed

Affiliation: Department of Animal Medicine, Production and Health, Doctoral School of Veterinary Sciences, University of Padova, Padova, Italy Division of Comparative Biomedical Sciences, Istituto Zooprofilattico Sperimentale delle Venezie, Legnaro, Padova, Italy.

Show MeSH

Related in: MedlinePlus

Infection of explants derived from swine nasal mucosa and trachea with evolutionary distinct H3N8 EIVs. (a) Histological features of swine nasal mucosa explants infected with H3N2 SIV (positive control) and various H3N8 EIVs (Uruguay/63, Fontainebleau/79, Argentina/95 and South Africa/2003). Lesions are shown in sections stained with haematoxylin and eosin (H&E). Infected cells were detected by immunohistochemical (IHC) staining of the NP viral protein. Positive cells are stained in brown. Black horizontal bars represent 50 µm. (b) Growth kinetics of the viruses described in (a) in swine tracheal explants. Dots represent values of individual replicates, * P<0.05. (c) Graphical representation of bead clearance assays in infected and control swine tracheal explants. Lines represent the average time to clear the beads in three independent experiments. Error bars represent SEM. (d) Histological features of swine tracheal explants infected with the viruses described in (a). Lesions and infected cells are described as in (a). Bars, 50 µm. Panels (a) and (c) show explants at day two p.i.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4631061&req=5

f2: Infection of explants derived from swine nasal mucosa and trachea with evolutionary distinct H3N8 EIVs. (a) Histological features of swine nasal mucosa explants infected with H3N2 SIV (positive control) and various H3N8 EIVs (Uruguay/63, Fontainebleau/79, Argentina/95 and South Africa/2003). Lesions are shown in sections stained with haematoxylin and eosin (H&E). Infected cells were detected by immunohistochemical (IHC) staining of the NP viral protein. Positive cells are stained in brown. Black horizontal bars represent 50 µm. (b) Growth kinetics of the viruses described in (a) in swine tracheal explants. Dots represent values of individual replicates, * P<0.05. (c) Graphical representation of bead clearance assays in infected and control swine tracheal explants. Lines represent the average time to clear the beads in three independent experiments. Error bars represent SEM. (d) Histological features of swine tracheal explants infected with the viruses described in (a). Lesions and infected cells are described as in (a). Bars, 50 µm. Panels (a) and (c) show explants at day two p.i.

Mentions: As expected, SIV consistently exhibited high replication efficiency in tracheas (Fig. 2b), lungs (Fig. 3b) and nasal mucosa (not shown). Histological damage was evident in the nasal mucosa displaying lesions such as epithelial disruption and vacuolization (Fig. 2a). Infected tracheas exhibited loss of cilia, reduction in epithelial thickness (Fig. 2d) and decreased ciliary function (Fig. 2c). SIV H3N2 antigen was also readily detected in all infected explants regardless of the anatomical location (Figs 2a, d and 3a).


Phylogenetically distinct equine influenza viruses show different tropism for the swine respiratory tract.

Patrono LV, Bonfante F, Zanardello C, Terregino C, Capua I, Murcia PR - J. Gen. Virol. (2015)

Infection of explants derived from swine nasal mucosa and trachea with evolutionary distinct H3N8 EIVs. (a) Histological features of swine nasal mucosa explants infected with H3N2 SIV (positive control) and various H3N8 EIVs (Uruguay/63, Fontainebleau/79, Argentina/95 and South Africa/2003). Lesions are shown in sections stained with haematoxylin and eosin (H&E). Infected cells were detected by immunohistochemical (IHC) staining of the NP viral protein. Positive cells are stained in brown. Black horizontal bars represent 50 µm. (b) Growth kinetics of the viruses described in (a) in swine tracheal explants. Dots represent values of individual replicates, * P<0.05. (c) Graphical representation of bead clearance assays in infected and control swine tracheal explants. Lines represent the average time to clear the beads in three independent experiments. Error bars represent SEM. (d) Histological features of swine tracheal explants infected with the viruses described in (a). Lesions and infected cells are described as in (a). Bars, 50 µm. Panels (a) and (c) show explants at day two p.i.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4631061&req=5

f2: Infection of explants derived from swine nasal mucosa and trachea with evolutionary distinct H3N8 EIVs. (a) Histological features of swine nasal mucosa explants infected with H3N2 SIV (positive control) and various H3N8 EIVs (Uruguay/63, Fontainebleau/79, Argentina/95 and South Africa/2003). Lesions are shown in sections stained with haematoxylin and eosin (H&E). Infected cells were detected by immunohistochemical (IHC) staining of the NP viral protein. Positive cells are stained in brown. Black horizontal bars represent 50 µm. (b) Growth kinetics of the viruses described in (a) in swine tracheal explants. Dots represent values of individual replicates, * P<0.05. (c) Graphical representation of bead clearance assays in infected and control swine tracheal explants. Lines represent the average time to clear the beads in three independent experiments. Error bars represent SEM. (d) Histological features of swine tracheal explants infected with the viruses described in (a). Lesions and infected cells are described as in (a). Bars, 50 µm. Panels (a) and (c) show explants at day two p.i.
Mentions: As expected, SIV consistently exhibited high replication efficiency in tracheas (Fig. 2b), lungs (Fig. 3b) and nasal mucosa (not shown). Histological damage was evident in the nasal mucosa displaying lesions such as epithelial disruption and vacuolization (Fig. 2a). Infected tracheas exhibited loss of cilia, reduction in epithelial thickness (Fig. 2d) and decreased ciliary function (Fig. 2c). SIV H3N2 antigen was also readily detected in all infected explants regardless of the anatomical location (Figs 2a, d and 3a).

Bottom Line: Previous work suggests that mutations acquired during EIV evolution might have played a role in CIV emergence.We show that phylogenetically distinct EIVs display different infection phenotypes along the pig respiratory tract, but not in cell lines.Our results suggest that EIV displays a dynamic host range along its evolutionary history, supporting the view that evolutionary processes play important roles in host range and tropism and also underscoring the utility of using explant cultures to study influenza pathogenesis.

View Article: PubMed Central - PubMed

Affiliation: Department of Animal Medicine, Production and Health, Doctoral School of Veterinary Sciences, University of Padova, Padova, Italy Division of Comparative Biomedical Sciences, Istituto Zooprofilattico Sperimentale delle Venezie, Legnaro, Padova, Italy.

Show MeSH
Related in: MedlinePlus