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The immunomodulating V and W proteins of Nipah virus determine disease course.

Satterfield BA, Cross RW, Fenton KA, Agans KN, Basler CF, Geisbert TW, Mire CE - Nat Commun (2015)

Bottom Line: Here we use recombinant NiVs (rNiVs) to examine the contributions of the NiV V and W proteins to NiV pathogenesis in a ferret model.Remarkably, rNiV lacking W expression results in a delayed and altered disease course with decreased respiratory disease and increased terminal neurological disease associated with altered in vitro inflammatory cytokine production.This study confirms the V protein as the major determinant of pathogenesis, also being the first in vivo study to show that the W protein modulates the inflammatory host immune response in a manner that determines the disease course.

View Article: PubMed Central - PubMed

Affiliation: 1] Galveston National Laboratory, University of Texas Medical Branch, 301 University Boulevard, Galveston, Texas 77555, USA [2] Department of Microbiology and Immunology, University of Texas Medical Branch, 301 University Boulevard, Galveston, Texas 77555, USA.

ABSTRACT
The viral determinants that contribute to Nipah virus (NiV)-mediated disease are poorly understood compared with other paramyxoviruses. Here we use recombinant NiVs (rNiVs) to examine the contributions of the NiV V and W proteins to NiV pathogenesis in a ferret model. We show that a V-deficient rNiV is susceptible to the innate immune response in vitro and behaves as a replicating non-lethal virus in vivo. Remarkably, rNiV lacking W expression results in a delayed and altered disease course with decreased respiratory disease and increased terminal neurological disease associated with altered in vitro inflammatory cytokine production. This study confirms the V protein as the major determinant of pathogenesis, also being the first in vivo study to show that the W protein modulates the inflammatory host immune response in a manner that determines the disease course.

No MeSH data available.


Related in: MedlinePlus

Model of the immunomodulating roles of the NiV W and V proteins in ferret pathogenesis.rNiVM-wt (a) spreads unhindered in early target lung endothelial cells (Fig. 2d) leading to extensive lung injury (Fig. 5a) followed by spread to the spleen (Fig. 5b) causing germinal centre necrosis (Fig. 6c) leading to a lack of neutralizing antibody response (Fig. 4d); there is also spread to the endothelium of the brain (Fig. 7d) and moderate neurological signs develop before the ferret succumbs to pulmonary disease. rNiVM-Wko (b) allows lung endothelial cells to generate an ‘inflammatory chemokine cloud' (Fig. 3 and Supplementary Table 1) somewhat hindering viral titres (Fig. 2d) and presumably allowing increased leukocyte recruitment to the lungs, limiting lung injury (Fig. 5d) and sequestering most viral spread to the endothelium and distinctive inflammatory nodules (Fig. 7f), thus causing milder respiratory signs; rNiVM-Wko is still able to spread to the spleen (Fig. 5e) causing germinal centre necrosis (Fig. 7g) and leading to a lack of neutralizing antibody response (Fig. 4d); there is also spread to the brain endothelium and, owing to prolonged time to death, eventually neurons as well leading to severe neurological signs and succumbing to neurological disease. rNiVM-Vko (C) in unable to grow efficiently in lung endothelial cells (Fig. 2d) possibly due to the production of an ‘innate cytokine cloud' (Fig. 3 and Supplementary Table 1) and is unable to efficiently spread or cause injury in the lungs (Fig. 5g), spleen (Fig. 5h) or brain (Fig. 7l); the splenic germinal centres remain intact (Fig. 6k) and a potent neutralizing antibody response develops (Fig. 4d) that leads to viral clearance and 100% ferret survival.
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f9: Model of the immunomodulating roles of the NiV W and V proteins in ferret pathogenesis.rNiVM-wt (a) spreads unhindered in early target lung endothelial cells (Fig. 2d) leading to extensive lung injury (Fig. 5a) followed by spread to the spleen (Fig. 5b) causing germinal centre necrosis (Fig. 6c) leading to a lack of neutralizing antibody response (Fig. 4d); there is also spread to the endothelium of the brain (Fig. 7d) and moderate neurological signs develop before the ferret succumbs to pulmonary disease. rNiVM-Wko (b) allows lung endothelial cells to generate an ‘inflammatory chemokine cloud' (Fig. 3 and Supplementary Table 1) somewhat hindering viral titres (Fig. 2d) and presumably allowing increased leukocyte recruitment to the lungs, limiting lung injury (Fig. 5d) and sequestering most viral spread to the endothelium and distinctive inflammatory nodules (Fig. 7f), thus causing milder respiratory signs; rNiVM-Wko is still able to spread to the spleen (Fig. 5e) causing germinal centre necrosis (Fig. 7g) and leading to a lack of neutralizing antibody response (Fig. 4d); there is also spread to the brain endothelium and, owing to prolonged time to death, eventually neurons as well leading to severe neurological signs and succumbing to neurological disease. rNiVM-Vko (C) in unable to grow efficiently in lung endothelial cells (Fig. 2d) possibly due to the production of an ‘innate cytokine cloud' (Fig. 3 and Supplementary Table 1) and is unable to efficiently spread or cause injury in the lungs (Fig. 5g), spleen (Fig. 5h) or brain (Fig. 7l); the splenic germinal centres remain intact (Fig. 6k) and a potent neutralizing antibody response develops (Fig. 4d) that leads to viral clearance and 100% ferret survival.

Mentions: While differences in circulating neutralizing antibodies did not appear to be responsible for differences between the rNiVM-wt and rNiVM-Wko cohorts, we attempted to understand why the rNiVM-Wko cohort exhibited less lung pathology than the rNiVM-wt cohort by examining the chemokine/cytokine profiles of infected HPMECs, the presumed early target cells in NiV infections. It was notable that many of the pro-inflammatory and leukocyte-attracting cytokines were at higher levels in supernatants from HPMECs infected with rNiVM-Wko than in HPMECs infected with either rNiVM-wt or rNiVM-Vko (Fig. 3 and Supplementary Table 1). Because the HPMECs were infected with a low MOI of 0.01 and presumably rNiVM-Vko was unable to spread effectively to other cells (Fig. 2d, green bars), the lower cytokine levels found in many of these supernatants is likely due to only a small proportion of the cells that were being infected and stimulated to produce the cytokines limiting the peak levels. However, both rNiVM-wt and rNiVM-Wko were presumably able to infect most or all of the cells in the well (Fig. 2d, blue and red bars, respectively) with rNiVM-Wko at slightly lower levels. Therefore, the higher levels of chemokines/cytokines produced by the rNiVM-Wko-infected HPMECs is likely due to the ability of the W protein to suppress and control chemokine/cytokine response in rNiVM-wt-infected HPMECs. These data suggest that the rNiVM-Wko-infected ferret cohort had an increased pulmonary chemokine/cytokine response, allowing for greater leukocyte recruitment to the lungs early in infection diminishing the severe insult to the lungs. In addition, this may explain the increased number and larger inflammatory nodules seen on histopathological examination for the rNiVM-Wko cohort (Fig. 7e,f) compared with the rNiVM-wt cohort (Fig. 7a,b) and why viral antigen was much more localized to only the endothelium and these inflammatory nodules in the rNiVM-Wko cohort. This may have some similarities to what was described with Cko rNiV-infected hamsters51, although this leads to some hamsters surviving instead of developing more severe neurological disease as was observed with our rNiVM-Wko ferret cohort. We have captured our overall interpretation of these data in Fig. 9.


The immunomodulating V and W proteins of Nipah virus determine disease course.

Satterfield BA, Cross RW, Fenton KA, Agans KN, Basler CF, Geisbert TW, Mire CE - Nat Commun (2015)

Model of the immunomodulating roles of the NiV W and V proteins in ferret pathogenesis.rNiVM-wt (a) spreads unhindered in early target lung endothelial cells (Fig. 2d) leading to extensive lung injury (Fig. 5a) followed by spread to the spleen (Fig. 5b) causing germinal centre necrosis (Fig. 6c) leading to a lack of neutralizing antibody response (Fig. 4d); there is also spread to the endothelium of the brain (Fig. 7d) and moderate neurological signs develop before the ferret succumbs to pulmonary disease. rNiVM-Wko (b) allows lung endothelial cells to generate an ‘inflammatory chemokine cloud' (Fig. 3 and Supplementary Table 1) somewhat hindering viral titres (Fig. 2d) and presumably allowing increased leukocyte recruitment to the lungs, limiting lung injury (Fig. 5d) and sequestering most viral spread to the endothelium and distinctive inflammatory nodules (Fig. 7f), thus causing milder respiratory signs; rNiVM-Wko is still able to spread to the spleen (Fig. 5e) causing germinal centre necrosis (Fig. 7g) and leading to a lack of neutralizing antibody response (Fig. 4d); there is also spread to the brain endothelium and, owing to prolonged time to death, eventually neurons as well leading to severe neurological signs and succumbing to neurological disease. rNiVM-Vko (C) in unable to grow efficiently in lung endothelial cells (Fig. 2d) possibly due to the production of an ‘innate cytokine cloud' (Fig. 3 and Supplementary Table 1) and is unable to efficiently spread or cause injury in the lungs (Fig. 5g), spleen (Fig. 5h) or brain (Fig. 7l); the splenic germinal centres remain intact (Fig. 6k) and a potent neutralizing antibody response develops (Fig. 4d) that leads to viral clearance and 100% ferret survival.
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Related In: Results  -  Collection

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f9: Model of the immunomodulating roles of the NiV W and V proteins in ferret pathogenesis.rNiVM-wt (a) spreads unhindered in early target lung endothelial cells (Fig. 2d) leading to extensive lung injury (Fig. 5a) followed by spread to the spleen (Fig. 5b) causing germinal centre necrosis (Fig. 6c) leading to a lack of neutralizing antibody response (Fig. 4d); there is also spread to the endothelium of the brain (Fig. 7d) and moderate neurological signs develop before the ferret succumbs to pulmonary disease. rNiVM-Wko (b) allows lung endothelial cells to generate an ‘inflammatory chemokine cloud' (Fig. 3 and Supplementary Table 1) somewhat hindering viral titres (Fig. 2d) and presumably allowing increased leukocyte recruitment to the lungs, limiting lung injury (Fig. 5d) and sequestering most viral spread to the endothelium and distinctive inflammatory nodules (Fig. 7f), thus causing milder respiratory signs; rNiVM-Wko is still able to spread to the spleen (Fig. 5e) causing germinal centre necrosis (Fig. 7g) and leading to a lack of neutralizing antibody response (Fig. 4d); there is also spread to the brain endothelium and, owing to prolonged time to death, eventually neurons as well leading to severe neurological signs and succumbing to neurological disease. rNiVM-Vko (C) in unable to grow efficiently in lung endothelial cells (Fig. 2d) possibly due to the production of an ‘innate cytokine cloud' (Fig. 3 and Supplementary Table 1) and is unable to efficiently spread or cause injury in the lungs (Fig. 5g), spleen (Fig. 5h) or brain (Fig. 7l); the splenic germinal centres remain intact (Fig. 6k) and a potent neutralizing antibody response develops (Fig. 4d) that leads to viral clearance and 100% ferret survival.
Mentions: While differences in circulating neutralizing antibodies did not appear to be responsible for differences between the rNiVM-wt and rNiVM-Wko cohorts, we attempted to understand why the rNiVM-Wko cohort exhibited less lung pathology than the rNiVM-wt cohort by examining the chemokine/cytokine profiles of infected HPMECs, the presumed early target cells in NiV infections. It was notable that many of the pro-inflammatory and leukocyte-attracting cytokines were at higher levels in supernatants from HPMECs infected with rNiVM-Wko than in HPMECs infected with either rNiVM-wt or rNiVM-Vko (Fig. 3 and Supplementary Table 1). Because the HPMECs were infected with a low MOI of 0.01 and presumably rNiVM-Vko was unable to spread effectively to other cells (Fig. 2d, green bars), the lower cytokine levels found in many of these supernatants is likely due to only a small proportion of the cells that were being infected and stimulated to produce the cytokines limiting the peak levels. However, both rNiVM-wt and rNiVM-Wko were presumably able to infect most or all of the cells in the well (Fig. 2d, blue and red bars, respectively) with rNiVM-Wko at slightly lower levels. Therefore, the higher levels of chemokines/cytokines produced by the rNiVM-Wko-infected HPMECs is likely due to the ability of the W protein to suppress and control chemokine/cytokine response in rNiVM-wt-infected HPMECs. These data suggest that the rNiVM-Wko-infected ferret cohort had an increased pulmonary chemokine/cytokine response, allowing for greater leukocyte recruitment to the lungs early in infection diminishing the severe insult to the lungs. In addition, this may explain the increased number and larger inflammatory nodules seen on histopathological examination for the rNiVM-Wko cohort (Fig. 7e,f) compared with the rNiVM-wt cohort (Fig. 7a,b) and why viral antigen was much more localized to only the endothelium and these inflammatory nodules in the rNiVM-Wko cohort. This may have some similarities to what was described with Cko rNiV-infected hamsters51, although this leads to some hamsters surviving instead of developing more severe neurological disease as was observed with our rNiVM-Wko ferret cohort. We have captured our overall interpretation of these data in Fig. 9.

Bottom Line: Here we use recombinant NiVs (rNiVs) to examine the contributions of the NiV V and W proteins to NiV pathogenesis in a ferret model.Remarkably, rNiV lacking W expression results in a delayed and altered disease course with decreased respiratory disease and increased terminal neurological disease associated with altered in vitro inflammatory cytokine production.This study confirms the V protein as the major determinant of pathogenesis, also being the first in vivo study to show that the W protein modulates the inflammatory host immune response in a manner that determines the disease course.

View Article: PubMed Central - PubMed

Affiliation: 1] Galveston National Laboratory, University of Texas Medical Branch, 301 University Boulevard, Galveston, Texas 77555, USA [2] Department of Microbiology and Immunology, University of Texas Medical Branch, 301 University Boulevard, Galveston, Texas 77555, USA.

ABSTRACT
The viral determinants that contribute to Nipah virus (NiV)-mediated disease are poorly understood compared with other paramyxoviruses. Here we use recombinant NiVs (rNiVs) to examine the contributions of the NiV V and W proteins to NiV pathogenesis in a ferret model. We show that a V-deficient rNiV is susceptible to the innate immune response in vitro and behaves as a replicating non-lethal virus in vivo. Remarkably, rNiV lacking W expression results in a delayed and altered disease course with decreased respiratory disease and increased terminal neurological disease associated with altered in vitro inflammatory cytokine production. This study confirms the V protein as the major determinant of pathogenesis, also being the first in vivo study to show that the W protein modulates the inflammatory host immune response in a manner that determines the disease course.

No MeSH data available.


Related in: MedlinePlus