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Minimal In Vivo Efficacy of Iminosugars in a Lethal Ebola Virus Guinea Pig Model

View Article: PubMed Central - PubMed

ABSTRACT

The antiviral properties of iminosugars have been reported previously in vitro and in small animal models against Ebola virus (EBOV); however, their effects have not been tested in larger animal models such as guinea pigs. We tested the iminosugars N-butyl-deoxynojirimycin (NB-DNJ) and N-(9-methoxynonyl)-1deoxynojirimycin (MON-DNJ) for safety in uninfected animals, and for antiviral efficacy in animals infected with a lethal dose of guinea pig adapted EBOV. 1850 mg/kg/day NB-DNJ and 120 mg/kg/day MON-DNJ administered intravenously, three times daily, caused no adverse effects and were well tolerated. A pilot study treating infected animals three times within an 8 hour period was promising with 1 of 4 infected NB-DNJ treated animals surviving and the remaining three showing improved clinical signs. MON-DNJ showed no protective effects when EBOV-infected guinea pigs were treated. On histopathological examination, animals treated with NB-DNJ had reduced lesion severity in liver and spleen. However, a second study, in which NB-DNJ was administered at equally-spaced 8 hour intervals, could not confirm drug-associated benefits. Neither was any antiviral effect of iminosugars detected in an EBOV glycoprotein pseudotyped virus assay. Overall, this study provides evidence that NB-DNJ and MON-DNJ do not protect guinea pigs from a lethal EBOV-infection at the dose levels and regimens tested. However, the one surviving animal and signs of improvements in three animals of the NB-DNJ treated cohort could indicate that NB-DNJ at these levels may have a marginal beneficial effect. Future work could be focused on the development of more potent iminosugars.

No MeSH data available.


Related in: MedlinePlus

Production of EBOV glycoprotein pseudotyped virus in the presence or absence of iminosugars does not alter infectivity.EBOV glycoprotein pseudotyped lentivirus was produced in the presence of 100μM of NB-DNJ, NN-DNJ, NB-DGJ or NN-DGJ, equivalent DMSO or media alone. The infectivity of these viruses was then assayed in HEK 293T cells in the (A) presence or (B) absence of homologous drug and recorded as luciferase reporter gene expression. The NIBSC international serological standard was included as a positive control for neutralisation. Pseudotyped virus production was undertaken twice, each time infections were performed in duplicate, and data analysed together. Average RLU are shown. For clarity the SD error is shown for only media and DMSO data but these are representative of all data sets. Single one phase exponential curves were fitted to the NB-DNJ, NB-DGJ and media data (solid line) and to NN-DNJ, NN-DGJ and DMSO data (dashed line).
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pone.0167018.g006: Production of EBOV glycoprotein pseudotyped virus in the presence or absence of iminosugars does not alter infectivity.EBOV glycoprotein pseudotyped lentivirus was produced in the presence of 100μM of NB-DNJ, NN-DNJ, NB-DGJ or NN-DGJ, equivalent DMSO or media alone. The infectivity of these viruses was then assayed in HEK 293T cells in the (A) presence or (B) absence of homologous drug and recorded as luciferase reporter gene expression. The NIBSC international serological standard was included as a positive control for neutralisation. Pseudotyped virus production was undertaken twice, each time infections were performed in duplicate, and data analysed together. Average RLU are shown. For clarity the SD error is shown for only media and DMSO data but these are representative of all data sets. Single one phase exponential curves were fitted to the NB-DNJ, NB-DGJ and media data (solid line) and to NN-DNJ, NN-DGJ and DMSO data (dashed line).

Mentions: We examined whether iminosugars could affect infectivity of a lentivirus pseudotyped with EBOV glycoprotein, by producing Ebola pseudotyped virus in the presence of either 100 μM NB-DNJ or NN-DNJ. The levels of infectious virus were then quantified in HEK 293T cells, both in the presence and absence of 100 μM iminosugar. A single one phase exponential curve could be used to describe the treatments in the presence or absence of iminosugars, excluding the negative control of cells alone and positive inhibition control of the NIBSC international serological standard. Iminosugars with an N-butyl head group were compared with media alone control as stocks were dissolved in water (pseudotyped virus produced in the presence of iminosugar: F = 2.491; p = 0.0515; pseudotyped virus produced in the absence of iminosugar: F = 0.4449; p = 0.7757); iminosugars with an N-nonyl head group were dissolved in DMSO hence were compared with equivalent DMSO control (pseudotyped virus produced in the presence of iminosugar: F = 1.521; p = 0.2061; pseudotyped virus produced in the absence of iminosugar: F = 0.5032; p = 0.7335). Fig 6 shows that neither NB-DNJ nor NN-DNJ alter the infectivity of Ebola pseudotyped virus in comparison to virus produced in the presence of media or DMSO alone. The control DGJ analogues also tested do not inhibit α-glucosidases and hence, as expected did not have any effect on pseudotyped virus infectivity. The inclusion of iminosugars during the assay for infectivity did not alter the lack of effect on pseudotyped virus infectivity, thus NB-DNJ and NN-DNJ do not affect pseudotyped virus infectivity.


Minimal In Vivo Efficacy of Iminosugars in a Lethal Ebola Virus Guinea Pig Model
Production of EBOV glycoprotein pseudotyped virus in the presence or absence of iminosugars does not alter infectivity.EBOV glycoprotein pseudotyped lentivirus was produced in the presence of 100μM of NB-DNJ, NN-DNJ, NB-DGJ or NN-DGJ, equivalent DMSO or media alone. The infectivity of these viruses was then assayed in HEK 293T cells in the (A) presence or (B) absence of homologous drug and recorded as luciferase reporter gene expression. The NIBSC international serological standard was included as a positive control for neutralisation. Pseudotyped virus production was undertaken twice, each time infections were performed in duplicate, and data analysed together. Average RLU are shown. For clarity the SD error is shown for only media and DMSO data but these are representative of all data sets. Single one phase exponential curves were fitted to the NB-DNJ, NB-DGJ and media data (solid line) and to NN-DNJ, NN-DGJ and DMSO data (dashed line).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5120828&req=5

pone.0167018.g006: Production of EBOV glycoprotein pseudotyped virus in the presence or absence of iminosugars does not alter infectivity.EBOV glycoprotein pseudotyped lentivirus was produced in the presence of 100μM of NB-DNJ, NN-DNJ, NB-DGJ or NN-DGJ, equivalent DMSO or media alone. The infectivity of these viruses was then assayed in HEK 293T cells in the (A) presence or (B) absence of homologous drug and recorded as luciferase reporter gene expression. The NIBSC international serological standard was included as a positive control for neutralisation. Pseudotyped virus production was undertaken twice, each time infections were performed in duplicate, and data analysed together. Average RLU are shown. For clarity the SD error is shown for only media and DMSO data but these are representative of all data sets. Single one phase exponential curves were fitted to the NB-DNJ, NB-DGJ and media data (solid line) and to NN-DNJ, NN-DGJ and DMSO data (dashed line).
Mentions: We examined whether iminosugars could affect infectivity of a lentivirus pseudotyped with EBOV glycoprotein, by producing Ebola pseudotyped virus in the presence of either 100 μM NB-DNJ or NN-DNJ. The levels of infectious virus were then quantified in HEK 293T cells, both in the presence and absence of 100 μM iminosugar. A single one phase exponential curve could be used to describe the treatments in the presence or absence of iminosugars, excluding the negative control of cells alone and positive inhibition control of the NIBSC international serological standard. Iminosugars with an N-butyl head group were compared with media alone control as stocks were dissolved in water (pseudotyped virus produced in the presence of iminosugar: F = 2.491; p = 0.0515; pseudotyped virus produced in the absence of iminosugar: F = 0.4449; p = 0.7757); iminosugars with an N-nonyl head group were dissolved in DMSO hence were compared with equivalent DMSO control (pseudotyped virus produced in the presence of iminosugar: F = 1.521; p = 0.2061; pseudotyped virus produced in the absence of iminosugar: F = 0.5032; p = 0.7335). Fig 6 shows that neither NB-DNJ nor NN-DNJ alter the infectivity of Ebola pseudotyped virus in comparison to virus produced in the presence of media or DMSO alone. The control DGJ analogues also tested do not inhibit α-glucosidases and hence, as expected did not have any effect on pseudotyped virus infectivity. The inclusion of iminosugars during the assay for infectivity did not alter the lack of effect on pseudotyped virus infectivity, thus NB-DNJ and NN-DNJ do not affect pseudotyped virus infectivity.

View Article: PubMed Central - PubMed

ABSTRACT

The antiviral properties of iminosugars have been reported previously in vitro and in small animal models against Ebola virus (EBOV); however, their effects have not been tested in larger animal models such as guinea pigs. We tested the iminosugars N-butyl-deoxynojirimycin (NB-DNJ) and N-(9-methoxynonyl)-1deoxynojirimycin (MON-DNJ) for safety in uninfected animals, and for antiviral efficacy in animals infected with a lethal dose of guinea pig adapted EBOV. 1850 mg/kg/day NB-DNJ and 120 mg/kg/day MON-DNJ administered intravenously, three times daily, caused no adverse effects and were well tolerated. A pilot study treating infected animals three times within an 8 hour period was promising with 1 of 4 infected NB-DNJ treated animals surviving and the remaining three showing improved clinical signs. MON-DNJ showed no protective effects when EBOV-infected guinea pigs were treated. On histopathological examination, animals treated with NB-DNJ had reduced lesion severity in liver and spleen. However, a second study, in which NB-DNJ was administered at equally-spaced 8 hour intervals, could not confirm drug-associated benefits. Neither was any antiviral effect of iminosugars detected in an EBOV glycoprotein pseudotyped virus assay. Overall, this study provides evidence that NB-DNJ and MON-DNJ do not protect guinea pigs from a lethal EBOV-infection at the dose levels and regimens tested. However, the one surviving animal and signs of improvements in three animals of the NB-DNJ treated cohort could indicate that NB-DNJ at these levels may have a marginal beneficial effect. Future work could be focused on the development of more potent iminosugars.

No MeSH data available.


Related in: MedlinePlus