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Characterizing the anti-HIV activity of papuamide A.

Andjelic CD, Planelles V, Barrows LR - Mar Drugs (2008)

Bottom Line: This inhibition of viral entry was determined to not be due to papuamide A binding to CD4 or HIV gp120, the two proteins involved in the cell-virus recognition and binding.Together, these results suggest a direct virucidal mechanism of HIV-1 inhibition by papuamide A.We also demonstrate here that the other papuamides (B-D) are able to inhibit viral entry indicating that the free amino moiety of 2,3-diaminobutanoic acid residue is not required for the virucidal activity.

View Article: PubMed Central - PubMed

Affiliation: University of Utah, Department of Pharmacology and Toxicology, 30 S. 2000 E. Rm.201, Salt Lake City, UT 84112, USA.

ABSTRACT
Papuamide A is representative of a class of marine derived cyclic depsipeptides, reported to have cytoprotective activity against HIV-1 in vitro. We show here that papuamide A acts as an entry inhibitor, preventing human immunodeficiency virus infection of host cells and that this inhibition is not specific to R5 or X4 tropic virus. This inhibition of viral entry was determined to not be due to papuamide A binding to CD4 or HIV gp120, the two proteins involved in the cell-virus recognition and binding. Furthermore, papuamide A was able to inhibit HIV pseudotype viruses expressing envelope glycoproteins from vesicular stomatitis virus or amphotropic murine leukemia virus indicating the mechanism of viral entry inhibition is not HIV-1 envelope glycoprotein specific. Time delayed addition studies with the pseudotyped viruses show that papuamide A inhibits viral infection only at the initial stage of the viral life cycle. Additionally, pretreatment studies revealed that the virus, and not the cell, is the target of papuamide A's action. Together, these results suggest a direct virucidal mechanism of HIV-1 inhibition by papuamide A. We also demonstrate here that the other papuamides (B-D) are able to inhibit viral entry indicating that the free amino moiety of 2,3-diaminobutanoic acid residue is not required for the virucidal activity.

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Related in: MedlinePlus

Papuamide A interacts directly with the virus. VSV pseudotype virus was incubated overnight with or without 178 nM papuamide A. Non-preincubated virus, preincubated virus, and non-preincubated virus with papuamide A were used to infect CEM-SS cells. Infection was determined by quantifying the percent of total cells expressing GFP. Data is representative of experiments with similar results repeated at least twice and is graphed as the mean ± standard error, n≥3. Percent infection was significantly different (p < 0.05) between infected cells that were untreated or treated with papuamide A (*).
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f6b-md-06-00528: Papuamide A interacts directly with the virus. VSV pseudotype virus was incubated overnight with or without 178 nM papuamide A. Non-preincubated virus, preincubated virus, and non-preincubated virus with papuamide A were used to infect CEM-SS cells. Infection was determined by quantifying the percent of total cells expressing GFP. Data is representative of experiments with similar results repeated at least twice and is graphed as the mean ± standard error, n≥3. Percent infection was significantly different (p < 0.05) between infected cells that were untreated or treated with papuamide A (*).

Mentions: In the virion fusion assay, cells were incubated with papuamide A for 2 hours prior to infection. Papuamide A containing medium was removed followed by two washes. This pretreatment protocol did not result in inhibition of viral entry demonstrating that papuamide A does not have an irreversible effect on the cell (Fig. 6a). Preincubation of the cells with papuamide A overnight also failed to inhibit viral infection (data not shown). Modification of the fusion assay was performed so that HIV was pretreated with papuamide A for 30 minutes prior to infection. Virus pretreatment, followed by dilution of virus, resulted in a rate of inhibition similar to when papuamide A was added at the same time as virus (Fig. 6a). However, in this experiment papuamide A could only be diluted, not completely removed from the virus and medium. Effective removal of unbound papuamide A after virus incubation requires ultracentrifugation, but ultracentrifugation of HIV enveloped virus greatly decreases virus infectivity [34, 35]. To overcome this problem, VSV-G pseudotype virus was used for pretreatment studies because VSV-G pseudotype virus has been shown to retain infectivity after ultracentrifugation [34]. VSV-G pseudotype virus was treated with papuamide A and incubated overnight. Virus was pelleted, papuamide A containing supernatant removed and pellet suspended in fresh medium. Virus pretreatment with papuamide A resulted in an approximate 50% decreased infectivity of the virus (Fig. 6b). This decreased infectivity was the same as that observed when papuamide A was added to cells at the same time as VSV-G pseudotype virus (control virus underwent overnight incubation with vehicle and ultracentrifugation to control for potential loss of infectivity due to this process). These results indicate that papuamide A either remains stably bound in an inhibitory association with the virions after ultracentrifugation and washing or, alternatively, papuamide A inactivates the virus.


Characterizing the anti-HIV activity of papuamide A.

Andjelic CD, Planelles V, Barrows LR - Mar Drugs (2008)

Papuamide A interacts directly with the virus. VSV pseudotype virus was incubated overnight with or without 178 nM papuamide A. Non-preincubated virus, preincubated virus, and non-preincubated virus with papuamide A were used to infect CEM-SS cells. Infection was determined by quantifying the percent of total cells expressing GFP. Data is representative of experiments with similar results repeated at least twice and is graphed as the mean ± standard error, n≥3. Percent infection was significantly different (p < 0.05) between infected cells that were untreated or treated with papuamide A (*).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2630844&req=5

f6b-md-06-00528: Papuamide A interacts directly with the virus. VSV pseudotype virus was incubated overnight with or without 178 nM papuamide A. Non-preincubated virus, preincubated virus, and non-preincubated virus with papuamide A were used to infect CEM-SS cells. Infection was determined by quantifying the percent of total cells expressing GFP. Data is representative of experiments with similar results repeated at least twice and is graphed as the mean ± standard error, n≥3. Percent infection was significantly different (p < 0.05) between infected cells that were untreated or treated with papuamide A (*).
Mentions: In the virion fusion assay, cells were incubated with papuamide A for 2 hours prior to infection. Papuamide A containing medium was removed followed by two washes. This pretreatment protocol did not result in inhibition of viral entry demonstrating that papuamide A does not have an irreversible effect on the cell (Fig. 6a). Preincubation of the cells with papuamide A overnight also failed to inhibit viral infection (data not shown). Modification of the fusion assay was performed so that HIV was pretreated with papuamide A for 30 minutes prior to infection. Virus pretreatment, followed by dilution of virus, resulted in a rate of inhibition similar to when papuamide A was added at the same time as virus (Fig. 6a). However, in this experiment papuamide A could only be diluted, not completely removed from the virus and medium. Effective removal of unbound papuamide A after virus incubation requires ultracentrifugation, but ultracentrifugation of HIV enveloped virus greatly decreases virus infectivity [34, 35]. To overcome this problem, VSV-G pseudotype virus was used for pretreatment studies because VSV-G pseudotype virus has been shown to retain infectivity after ultracentrifugation [34]. VSV-G pseudotype virus was treated with papuamide A and incubated overnight. Virus was pelleted, papuamide A containing supernatant removed and pellet suspended in fresh medium. Virus pretreatment with papuamide A resulted in an approximate 50% decreased infectivity of the virus (Fig. 6b). This decreased infectivity was the same as that observed when papuamide A was added to cells at the same time as VSV-G pseudotype virus (control virus underwent overnight incubation with vehicle and ultracentrifugation to control for potential loss of infectivity due to this process). These results indicate that papuamide A either remains stably bound in an inhibitory association with the virions after ultracentrifugation and washing or, alternatively, papuamide A inactivates the virus.

Bottom Line: This inhibition of viral entry was determined to not be due to papuamide A binding to CD4 or HIV gp120, the two proteins involved in the cell-virus recognition and binding.Together, these results suggest a direct virucidal mechanism of HIV-1 inhibition by papuamide A.We also demonstrate here that the other papuamides (B-D) are able to inhibit viral entry indicating that the free amino moiety of 2,3-diaminobutanoic acid residue is not required for the virucidal activity.

View Article: PubMed Central - PubMed

Affiliation: University of Utah, Department of Pharmacology and Toxicology, 30 S. 2000 E. Rm.201, Salt Lake City, UT 84112, USA.

ABSTRACT
Papuamide A is representative of a class of marine derived cyclic depsipeptides, reported to have cytoprotective activity against HIV-1 in vitro. We show here that papuamide A acts as an entry inhibitor, preventing human immunodeficiency virus infection of host cells and that this inhibition is not specific to R5 or X4 tropic virus. This inhibition of viral entry was determined to not be due to papuamide A binding to CD4 or HIV gp120, the two proteins involved in the cell-virus recognition and binding. Furthermore, papuamide A was able to inhibit HIV pseudotype viruses expressing envelope glycoproteins from vesicular stomatitis virus or amphotropic murine leukemia virus indicating the mechanism of viral entry inhibition is not HIV-1 envelope glycoprotein specific. Time delayed addition studies with the pseudotyped viruses show that papuamide A inhibits viral infection only at the initial stage of the viral life cycle. Additionally, pretreatment studies revealed that the virus, and not the cell, is the target of papuamide A's action. Together, these results suggest a direct virucidal mechanism of HIV-1 inhibition by papuamide A. We also demonstrate here that the other papuamides (B-D) are able to inhibit viral entry indicating that the free amino moiety of 2,3-diaminobutanoic acid residue is not required for the virucidal activity.

Show MeSH
Related in: MedlinePlus