The influence of porcine recombinant interferon- 1 on pseudorabies virus infection of porcine nasal mucosa in vitro

Abstract

To determine the effect of interferon (IFN) on the pathogenesis of pseudorabies virus (PRV), porcine nasal mucosal explants were first treated with recombinant porcine methionyl-IFN-atl and then infected with one of three strains of PRV. The stroma of treated mucosal explants were protected against infection with virulent PRV or PRV of intermediate virulence because the infection was restricted to the epithelial cells. In contrast, untreated mucosal explants were readily infected by virulent PRV or PRV of intermediate virulence; the infection spread from epithelial cells to stromal fibroblasts. Avirulent PRV infection was restricted to the epithelial cells of treated and untreated mucosal explants. IFN treatment limited the extent of all three PRV infections in the epithelial cells. Cultured porcine fibroblasts and porcine kidney cells were also treated with IFN and subsequently infected with PRV; infection was prevented in most porcine fibroblasts and the virus yield from porcine kidney cells was reduced. Budding of virulent PRV nucleocapsids through the inner nuclear membrane was observed more frequently in treated than in untreated mucosal explants and enveloped virus particles accumulated between the inner and outer nuclear membranes, indicating that the membrane-associated events of PRV replication had been affected. We conclude that IFN-at protects stromal fibroblasts against PRV infection and reduces virus replication in epithelial cells.

Pathological, ultrastructural, and immunohistochemical changes caused by Lelystad virus in experimentally induced infections of mystery swine disease (synonym: Porcine epidemic abortion and respiratory syndrome (PEARS))

“…Tissue specimens of nasal mucosa, lung, trachea, tonsils, thymus, heart, liver, spleen, kidney, adrenal gland, stomach, duodenum, mesenteric lymph nodes, pancreas, thyroid, and brain were fixed in 10% neutral-buffered formalin and processed as described elsewhere (9).…”

Characterization of the porcine alpha interferon multigene family

“…The antiviral activity of PoIFN-α was tested on WISH cells/ Vesicular Stomatitis Virus (VSV) system (LaFleur et al, 2001) and PK 15 cells/Pseudorabies Virus (PRV) system (Pol et al, 1991) respectively. Briefly, the cells were seeded in flat-bottom 96-well plates and grown to 95% confluence, and serial dilutions of PoIFN-α were added to the wells.…”

Cell biological and molecular characteristics of pseudorabies virus infections in cell cultures and in pigs with emphasis on the respiratory tract

“…The latter shows the importance of interferon-alpha in the control of virus replication in the nose and pharynx. Using nasal mucosal explants, Pol et al [52] demonstrated that interferon-alpha is diminishing the spread of PrV in the connective tissue but not in the epithelial cells. The reason why epithelial cells are not protected is not understood and should be further analyzed.…”