scholarly journals Synthesis and Evaluation of Some Masked Phosphate Esters of the Anti-Herpesvirus Drug 882C (Netivudine) as Potential Antiviral Agents

1998 ◽  
Vol 9 (3) ◽  
pp. 233-243 ◽  
Author(s):  
C McGuigan ◽  
A Perry ◽  
CJ Yarnold ◽  
PW Sutton ◽  
D Lowe ◽  
...  
Keyword(s):  
Influenza A Virus ◽  
Virus Type ◽  
Influenza A ◽  
Relative Rate ◽  
Antiviral Agents ◽  
Phosphate Esters ◽  
Lead Target ◽  
Immunodeficiency Virus ◽  
Simplex Virus

A number of symmetric and asymmetric 5′-phosphate esters of the potent anti-varicellazoster virus (VZV) agent 1–(β-d-arabinofuranosyl)-5-prop-1-ynyluracil (882C; netivudine) were prepared as potential lipophilic, membrane-soluble prodrugs of the bioactive phosphate forms. The compounds were prepared by the base-catalysed coupling of various phosphorochloridates with the free nucleoside analogue. Compounds were fully characterized by a range of spectroscopic and analytical methods and were studied for their inhibition of several viruses in tissue culture. All of the phosphate esters were inactive against human cytomegalovirus, herpes simplex virus type 2, VZV, human immunodeficiency virus type 1 and influenza A virus (EC50 >100 μM) except the 5′-(4–nitrophenyl phenyl) phosphate, which inhibited influenza A virus. The relative rate of esterase-mediated hydrolysis of one of the lead target structures was measured in order to rationalize the poor antiviral action, and data were collected on possible metabolites in support of this analysis. Cell-specific esterases are implicated as key determinants of the antiviral potency of prodrugs of this type.

scholarly journals Inhibition of Human Immunodeficiency Virus Type 1 Replication prior to Reverse Transcription by Influenza Virus Stimulation

2000 ◽  
Vol 74 (10) ◽  
pp. 4505-4511 ◽  
Author(s):  
Ligia A. Pinto ◽  
Vesna Blazevic ◽  
Bruce K. Patterson ◽  
C. Mac Trubey ◽  
Matthew J. Dolan ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Influenza A Virus ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Reverse Transcription ◽  
Influenza A ◽  
Immunodeficiency Virus ◽  
Anti Hiv ◽  
Hiv 1

ABSTRACT It is now recognized that, in addition to drug-mediated therapies against human immunodeficiency virus type 1 (HIV-1), the immune system can exert antiviral effects via CD8+ T-cell-generated anti-HIV factors. This study demonstrates that (i) supernatants from peripheral blood mononuclear cells (PBMC) stimulated with influenza A virus inhibit replication of CCR5- and CXCR4-tropic HIV-1 isolates prior to reverse transcription; (ii) the HIV-suppressive supernatants can be generated by CD4- or CD8-depleted PBMC; (iii) this anti-HIV activity is partially due to alpha interferon (IFN-α), but not to IFN-γ, IFN-β, the β-chemokines MIP-1α, MIP-1β, and RANTES, or interleukin-16; (iv) the anti-HIV activity is generated equally well by PBMC cultured with either infectious or UV-inactivated influenza A virus; and (v) the antiviral activity can be generated by influenza A-stimulated PBMC from HIV-infected individuals. These findings represent a novel mechanism for inhibition of HIV-1 replication that differs from the previously described CD8 anti-HIV factors (MIP-1α, MIP-1β, RANTES, and CD8 antiviral factor).

scholarly journals Stoichiometry of Envelope Glycoprotein Trimers in the Entry of Human Immunodeficiency Virus Type 1

2005 ◽  
Vol 79 (19) ◽  
pp. 12132-12147 ◽  
Author(s):  
Xinzhen Yang ◽  
Svetla Kurteva ◽  
Xinping Ren ◽  
Sandra Lee ◽  
Joseph Sodroski
Keyword(s):  
Human Immunodeficiency Virus ◽  
Membrane Fusion ◽  
Influenza A Virus ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Influenza A ◽  
Virus Entry ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT The human immunodeficiency virus type 1 (HIV-1) envelope glycoproteins (Envs) function as a trimer, mediating virus entry by promoting the fusion of the viral and target cell membranes. HIV-1 Env trimers induce membrane fusion through a pH-independent pathway driven by the interaction between an Env trimer and its cellular receptors, CD4 and CCR5/CXCR4. We studied viruses with mixed heterotrimers of wild-type and dominant-negative Envs to determine the number (T) of Env trimers required for HIV-1 entry. To our surprise, we found that a single Env trimer is capable of supporting HIV-1 entry; i.e., T = 1. A similar approach was applied to investigate the entry stoichiometry of envelope glycoproteins from amphotropic murine leukemia virus (A-MLV), avian sarcoma/leukosis virus type A (ASLV-A), and influenza A virus. When pseudotyped on HIV-1 virions, the A-MLV and ASLV-A Envs also exhibit a T = 1 entry stoichiometry. In contrast, eight to nine influenza A virus hemagglutinin trimers function cooperatively to achieve membrane fusion and virus entry, using a pH-dependent pathway. The different entry requirements for cooperativity among Env trimers for retroviruses and influenza A virus may influence viral strategies for replication and evasion of the immune system.

scholarly journals Baseline Resistance of Primary Human Immunodeficiency Virus Type 1 Strains to the CXCR4 Inhibitor AMD3100

2008 ◽  
Vol 82 (23) ◽  
pp. 11695-11704 ◽  
Author(s):  
Jessamina E. Harrison ◽  
Jonathan B. Lynch ◽  
Luz-Jeannette Sierra ◽  
Leslie A. Blackburn ◽  
Neelanjana Ray ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Antiviral Agents ◽  
Viral Envelope ◽  
Cxcr4 Antagonist ◽  
Immunodeficiency Virus ◽  
Env Protein ◽  
Hiv 1

ABSTRACT We screened a panel of R5X4 and X4 human immunodeficiency virus type 1 (HIV-1) strains for their sensitivities to AMD3100, a small-molecule CXCR4 antagonist that blocks HIV-1 infection via this coreceptor. While no longer under clinical development, AMD3100 is a useful tool with which to probe interactions between the viral envelope (Env) protein and CXCR4 and to identify pathways by which HIV-1 may become resistant to this class of antiviral agents. While infection by most virus strains was completely blocked by AMD3100, we identified several R5X4 and X4 isolates that exhibited plateau effects: as the AMD3100 concentration was increased, virus infection and membrane fusion diminished to variable degrees. Once saturating concentrations of AMD3100 were achieved, further inhibition was not observed, indicating a noncompetitive mode of viral resistance to the drug. The magnitude of the plateau varied depending on the virus isolate, as well as the cell type used, with considerable variation observed when primary human T cells from different human donors were used. Structure-function studies indicated that the V1/V2 region of the R5X4 HIV-1 isolate DH12 was necessary for AMD3100 resistance and could confer this property on two heterologous Env proteins. We conclude that some R5X4 and X4 HIV-1 isolates can utilize the AMD3100-bound conformation of CXCR4, with the efficiency being influenced by both viral and host factors. Baseline resistance to this CXCR4 antagonist could influence the clinical use of such compounds.

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