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. 2010 Sep 15;5(9):e12709.
doi: 10.1371/journal.pone.0012709.

The nonstructural proteins of Nipah virus play a key role in pathogenicity in experimentally infected animals

Misako Yoneda  1 , Vanessa Guillaume, Hiroki Sato, Kentaro Fujita, Marie-Claude Georges-Courbot, Fusako Ikeda, Mio Omi, Yuri Muto-Terao, T Fabian Wild, Chieko Kai
Affiliations

The nonstructural proteins of Nipah virus play a key role in pathogenicity in experimentally infected animals

Misako Yoneda et al. PLoS One. .

Abstract

Nipah virus (NiV) P gene encodes P protein and three accessory proteins (V, C and W). It has been reported that all four P gene products have IFN antagonist activity when the proteins were transiently expressed. However, the role of those accessory proteins in natural infection with NiV remains unknown. We generated recombinant NiVs lacking V, C or W protein, rNiV(V-), rNiV(C-), and rNiV(W-), respectively, to analyze the functions of these proteins in infected cells and the implications in in vivo pathogenicity. All the recombinants grew well in cell culture, although the maximum titers of rNiV(V-) and rNiV(C-) were lower than the other recombinants. The rNiV(V-), rNiV(C-) and rNiV(W-) suppressed the IFN response as well as the parental rNiV, thereby indicating that the lack of each accessory protein does not significantly affect the inhibition of IFN signaling in infected cells. In experimentally infected golden hamsters, rNiV(V-) and rNiV(C-) but not the rNiV(W-) virus showed a significant reduction in virulence. These results suggest that V and C proteins play key roles in NiV pathogenicity, and the roles are independent of their IFN-antagonist activity. This is the first report that identifies the molecular determinants of NiV in pathogenicity in vivo.

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Conflict of interest statement

Competing Interests: The authors have declared that no competing interests exist.

Figures

Figure 1
Figure 1. Nipah P, V, W and C proteins inhibit IFN-signaling.
293 cells were transfected with pISRE-luc, an internal control vector pRL-CMV and the indicated expression constructs (P, V, W or C) or empty vector (ctrl). At 36 h post transfection, the medium was changed to one containing 1 000 IU/ml of IFN-α. Luciferase assay was performed after 8 h incubation. All data were normalized by the expression level of Renilla luciferase, and the relative luciferase activity of the IFN-α treated (right shaded column) and untreated (left open column) cells is shown. The numbers at the top of the columns indicate the fold increase of luciferase activity upon IFN-α treatment. Error bars indicate the means ± the SD of three experiments.
Figure 2
Figure 2. Generation of recombinant NiVs.
(A) A single nucleotide change introduced into P gene ORF to produce recombinant NiVs lacking V, W or C protein. (B) Immunoblot analysis of the V, W and C proteins expressed in Vero cells infected with the parental rNiV, rNiV(V−), rNiV(W−) and rNiV(C−) (WT, V−, W−, and C−, respectively). Uninfected Vero cells (mock:M) were used as controls. Arrows indicate V (left panel), W (middle panel) or C (right panel) protein.
Figure 3
Figure 3. Comparison of the replication of the parent wild type (rNiV) and of the recombinant viruses, rNiV(V−), rNiV(W−) and rNiV(C−).
Vero and 293 cells were infected with each virus at a moi of 0.01 pfu/cell for 1 h. Cell supernatants were collected at the indicated time points for the determination of virus titer. Error bars indicate means ± SD from three experiments.
Figure 4
Figure 4. NiV inhibits the induction of luciferase expression from IFN responsive promoter.
Vero cells were transfected with luciferase reporter plasmids under the control of the IFN-α promoter (pISRE-luc) and after 48 h, the cells were infected with rNiV, rNiV(V−), rNiV(W−) or rNiV(C−). At 24 h post infection, cells were treated with 1000 U of IFN-α for 24 h, lysed, and the luciferase activities were measured. Error bars indicate means ± SD of the three experiments.
Figure 5
Figure 5. Survival curves of the hamsters infected with different quantities of the recombinant viruses.
Hamsters (6 groups) were inoculated intraperitoneally with 10-fold serial dilutions of either NiV or rNiVs and survival rate of each group was observed for 30 days. (A) shows survival curves of hamsters infected with rNiV(W−) and (B) shows that of hamsters infected with rNiV(V−) and rNiV(C−).
Figure 6
Figure 6. Histopathology in lungs.
The thin sections of kidney samples obtained from hamsters infected with rNiV, rNiV(V−), rNiV(C−) and rNiV(W−), were stained with hematoxylin and eosin. Severe inflammation lesions were observed in lung from rNiV or rNiV(W−) infected hamsters. In lung of rNiV(C−) infected hamsters, mild infiltration and inflammation were observed. The lung from rNiV(V−) was normal.
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References

    1. Chua KB, Bellini WJ, Rota PA, Harcourt BH, Tamin A, et al. Nipah virus: a recently emergent deadly paramyxovirus. Science. 2000;288:1432–1435. - PubMed
    1. Epstein JH, Abdul Rahman S, Zambriski JA, Halpin K, Meehan G, et al. Feral cats and risk for Nipah virus transmission. Emerg Infect Dis. 2006;12:1178–1179. - PMC - PubMed
    1. Butler D. Fatal fruit bat virus sparks epidemics in southern Asia. Nature. 2004;429:7. - PMC - PubMed
    1. Chadha MS, Comer JA, Lowe L, Rota PA, Rollin PE, et al. Nipah virus-associated encephalitis outbreak, Siliguri, India. Emerg Infect Dis. 2006;12:235–240. - PMC - PubMed
    1. Enserink M. Emerging infectious diseases. Nipah virus (or a cousin) strikes again. Science. 2004;303:1121. - PubMed

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