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Structure activity relationship of dendrimer microbicides with dual action antiviral activity.

Tyssen D, Henderson SA, Johnson A, Sterjovski J, Moore K, La J, Zanin M, Sonza S, Karellas P, Giannis MP, Krippner G, Wesselingh S, McCarthy T, Gorry PR, Ramsland PA, Cone R, Paull JR, Lewis GR, Tachedjian G - PLoS ONE (2010)

Bottom Line: Their anti-HIV-1 activity did not appreciably increase beyond a second-generation dendrimer while dendrimers larger than two generations were required for potent anti-HSV-2 activity.SPL7013 is formulated as VivaGel(R) and is currently in clinical development to provide protection against HIV and HSV.SPL7013 could also be combined with other microbicides.

View Article: PubMed Central - PubMed

Affiliation: Centres for Virology and Immunology, Burnet Institute, Melbourne, Victoria, Australia.

ABSTRACT

Background: Topical microbicides, used by women to prevent the transmission of HIV and other sexually transmitted infections are urgently required. Dendrimers are highly branched nanoparticles being developed as microbicides. However, the anti-HIV and HSV structure-activity relationship of dendrimers comprising benzyhydryl amide cores and lysine branches, and a comprehensive analysis of their broad-spectrum anti-HIV activity and mechanism of action have not been published.

Methods and findings: Dendrimers with optimized activity against HIV-1 and HSV-2 were identified with respect to the number of lysine branches (generations) and surface groups. Antiviral activity was determined in cell culture assays. Time-of-addition assays were performed to determine dendrimer mechanism of action. In vivo toxicity and HSV-2 inhibitory activity were evaluated in the mouse HSV-2 susceptibility model. Surface groups imparting the most potent inhibitory activity against HIV-1 and HSV-2 were naphthalene disulfonic acid (DNAA) and 3,5-disulfobenzoic acid exhibiting the greatest anionic charge and hydrophobicity of the seven surface groups tested. Their anti-HIV-1 activity did not appreciably increase beyond a second-generation dendrimer while dendrimers larger than two generations were required for potent anti-HSV-2 activity. Second (SPL7115) and fourth generation (SPL7013) DNAA dendrimers demonstrated broad-spectrum anti-HIV activity. However, SPL7013 was more active against HSV and blocking HIV-1 envelope mediated cell-to-cell fusion. SPL7013 and SPL7115 inhibited viral entry with similar potency against CXCR4-(X4) and CCR5-using (R5) HIV-1 strains. SPL7013 was not toxic and provided at least 12 h protection against HSV-2 in the mouse vagina.

Conclusions: Dendrimers can be engineered with optimized potency against HIV and HSV representing a unique platform for the controlled synthesis of chemically defined multivalent agents as viral entry inhibitors. SPL7013 is formulated as VivaGel(R) and is currently in clinical development to provide protection against HIV and HSV. SPL7013 could also be combined with other microbicides.

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Electrostatic surface views of dendrimer and gp120 models.(A) Models of the G2 (SPL7115) and G4 (SPL7013) dendrimers taken from the last frame of a molecular dynamics simulation [31]. Two views are shown (top and bottom) rotated by 180° around the long axis of the dendrimer. (B) Two views (rotated by 180°) of the homology model of the DRNL wild-type gp120. CD4 binding site is denoted by a yellow outline and conserved residues K121, R325, R417, K419 and K430 in the CD4i domain are indicated. (C) Side-view of the DRNL gp120 trimer with the V3 loops pointing towards the target cell membrane. The space between the gp120 monomers would normally be occupied by gp41. (D) End-on view of the DRNL gp120 trimer with the V3 loops facing the viewer. Predicted position of gp41 monomers are marked by an asterisk. In all views, the solvent-accessible surfaces are mapped with regions of negative (red) and positive (blue) electrostatic potential (charge).
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pone-0012309-g005: Electrostatic surface views of dendrimer and gp120 models.(A) Models of the G2 (SPL7115) and G4 (SPL7013) dendrimers taken from the last frame of a molecular dynamics simulation [31]. Two views are shown (top and bottom) rotated by 180° around the long axis of the dendrimer. (B) Two views (rotated by 180°) of the homology model of the DRNL wild-type gp120. CD4 binding site is denoted by a yellow outline and conserved residues K121, R325, R417, K419 and K430 in the CD4i domain are indicated. (C) Side-view of the DRNL gp120 trimer with the V3 loops pointing towards the target cell membrane. The space between the gp120 monomers would normally be occupied by gp41. (D) End-on view of the DRNL gp120 trimer with the V3 loops facing the viewer. Predicted position of gp41 monomers are marked by an asterisk. In all views, the solvent-accessible surfaces are mapped with regions of negative (red) and positive (blue) electrostatic potential (charge).

Mentions: Our studies demonstrate that SPL7013 and SPL7115 block HIV-1 entry indicating that they bind to HIV-1 surface proteins and/or host cell receptors required for entry. In this regard, previous studies have demonstrated that the anionic polymer, PRO 2000, harboring naphthalene monosulfonic acid residues, binds to HIV gp120 in addition to CD4 and the CXCR4 chemokine receptor [28], [29]. Moreover, multiple mutations in HIV-1 gp120 are required to develop resistance to dendrimers as observed for the related DNAA dendrimer SPL2923 [11], [30]. Taken together, these studies indicate that HIV-1 gp120 is one of the targets of DNAA based dendrimers. To understand how SPL7115 and SPL7013 bind to gp120 we generated electrostatic surface views of the dendrimer and the gp120 target as either a monomer or a trimer (Figure 5). As previously described [31], L-lysine dendrimers with DNAA caps are predicted to transition from an elongated structure (G2, SPL7115) to a more compact or globular structure in later generations (G4, SPL7013). The DNAA moieties on the dendrimers are predicted to cluster, especially in earlier generations, resulting in a high density of negative charge on one face of the G2 and G4 molecules (Figure 5A).


Structure activity relationship of dendrimer microbicides with dual action antiviral activity.

Tyssen D, Henderson SA, Johnson A, Sterjovski J, Moore K, La J, Zanin M, Sonza S, Karellas P, Giannis MP, Krippner G, Wesselingh S, McCarthy T, Gorry PR, Ramsland PA, Cone R, Paull JR, Lewis GR, Tachedjian G - PLoS ONE (2010)

Electrostatic surface views of dendrimer and gp120 models.(A) Models of the G2 (SPL7115) and G4 (SPL7013) dendrimers taken from the last frame of a molecular dynamics simulation [31]. Two views are shown (top and bottom) rotated by 180° around the long axis of the dendrimer. (B) Two views (rotated by 180°) of the homology model of the DRNL wild-type gp120. CD4 binding site is denoted by a yellow outline and conserved residues K121, R325, R417, K419 and K430 in the CD4i domain are indicated. (C) Side-view of the DRNL gp120 trimer with the V3 loops pointing towards the target cell membrane. The space between the gp120 monomers would normally be occupied by gp41. (D) End-on view of the DRNL gp120 trimer with the V3 loops facing the viewer. Predicted position of gp41 monomers are marked by an asterisk. In all views, the solvent-accessible surfaces are mapped with regions of negative (red) and positive (blue) electrostatic potential (charge).
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC2925893&req=5

pone-0012309-g005: Electrostatic surface views of dendrimer and gp120 models.(A) Models of the G2 (SPL7115) and G4 (SPL7013) dendrimers taken from the last frame of a molecular dynamics simulation [31]. Two views are shown (top and bottom) rotated by 180° around the long axis of the dendrimer. (B) Two views (rotated by 180°) of the homology model of the DRNL wild-type gp120. CD4 binding site is denoted by a yellow outline and conserved residues K121, R325, R417, K419 and K430 in the CD4i domain are indicated. (C) Side-view of the DRNL gp120 trimer with the V3 loops pointing towards the target cell membrane. The space between the gp120 monomers would normally be occupied by gp41. (D) End-on view of the DRNL gp120 trimer with the V3 loops facing the viewer. Predicted position of gp41 monomers are marked by an asterisk. In all views, the solvent-accessible surfaces are mapped with regions of negative (red) and positive (blue) electrostatic potential (charge).
Mentions: Our studies demonstrate that SPL7013 and SPL7115 block HIV-1 entry indicating that they bind to HIV-1 surface proteins and/or host cell receptors required for entry. In this regard, previous studies have demonstrated that the anionic polymer, PRO 2000, harboring naphthalene monosulfonic acid residues, binds to HIV gp120 in addition to CD4 and the CXCR4 chemokine receptor [28], [29]. Moreover, multiple mutations in HIV-1 gp120 are required to develop resistance to dendrimers as observed for the related DNAA dendrimer SPL2923 [11], [30]. Taken together, these studies indicate that HIV-1 gp120 is one of the targets of DNAA based dendrimers. To understand how SPL7115 and SPL7013 bind to gp120 we generated electrostatic surface views of the dendrimer and the gp120 target as either a monomer or a trimer (Figure 5). As previously described [31], L-lysine dendrimers with DNAA caps are predicted to transition from an elongated structure (G2, SPL7115) to a more compact or globular structure in later generations (G4, SPL7013). The DNAA moieties on the dendrimers are predicted to cluster, especially in earlier generations, resulting in a high density of negative charge on one face of the G2 and G4 molecules (Figure 5A).

Bottom Line: Their anti-HIV-1 activity did not appreciably increase beyond a second-generation dendrimer while dendrimers larger than two generations were required for potent anti-HSV-2 activity.SPL7013 is formulated as VivaGel(R) and is currently in clinical development to provide protection against HIV and HSV.SPL7013 could also be combined with other microbicides.

View Article: PubMed Central - PubMed

Affiliation: Centres for Virology and Immunology, Burnet Institute, Melbourne, Victoria, Australia.

ABSTRACT

Background: Topical microbicides, used by women to prevent the transmission of HIV and other sexually transmitted infections are urgently required. Dendrimers are highly branched nanoparticles being developed as microbicides. However, the anti-HIV and HSV structure-activity relationship of dendrimers comprising benzyhydryl amide cores and lysine branches, and a comprehensive analysis of their broad-spectrum anti-HIV activity and mechanism of action have not been published.

Methods and findings: Dendrimers with optimized activity against HIV-1 and HSV-2 were identified with respect to the number of lysine branches (generations) and surface groups. Antiviral activity was determined in cell culture assays. Time-of-addition assays were performed to determine dendrimer mechanism of action. In vivo toxicity and HSV-2 inhibitory activity were evaluated in the mouse HSV-2 susceptibility model. Surface groups imparting the most potent inhibitory activity against HIV-1 and HSV-2 were naphthalene disulfonic acid (DNAA) and 3,5-disulfobenzoic acid exhibiting the greatest anionic charge and hydrophobicity of the seven surface groups tested. Their anti-HIV-1 activity did not appreciably increase beyond a second-generation dendrimer while dendrimers larger than two generations were required for potent anti-HSV-2 activity. Second (SPL7115) and fourth generation (SPL7013) DNAA dendrimers demonstrated broad-spectrum anti-HIV activity. However, SPL7013 was more active against HSV and blocking HIV-1 envelope mediated cell-to-cell fusion. SPL7013 and SPL7115 inhibited viral entry with similar potency against CXCR4-(X4) and CCR5-using (R5) HIV-1 strains. SPL7013 was not toxic and provided at least 12 h protection against HSV-2 in the mouse vagina.

Conclusions: Dendrimers can be engineered with optimized potency against HIV and HSV representing a unique platform for the controlled synthesis of chemically defined multivalent agents as viral entry inhibitors. SPL7013 is formulated as VivaGel(R) and is currently in clinical development to provide protection against HIV and HSV. SPL7013 could also be combined with other microbicides.

Show MeSH
Related in: MedlinePlus