Anne Marie Aubertin

Intracellular delivery of nucleoside monophosphates through a reductase-mediated activation process

On the basis of three different models (namely: ddU, AZT and PMEA), mononucleotide phosphotriester derivatives were designed to be able to liberate the corresponding monophosphate (or phosphonate) inside the cell through a reductase-mediated activation process. It was demonstrated that the use of bis[S-(2-hydroxyethylsulfidyl)-2-thioethyl] esters of ddUMP (11), AZTMP (12) and PMEA (17) resulted in intracellular delivery of the parent monophosphate (or phosphonate). This point was corroborated by observation of an anti-HIV effect of, 11 in various cell lines, for 12 in CEM TK- cells and by the enhanced activity observed for 17. Furthermore, the reported decomposition data in cell extracts fully confirm the validity of this approach and show unambiguously the potential for intracellular reductase-mediated activation of the starting drug.

Equal inhibition of the replication of human immunodeficiency virus in human T-cell culture by ddA BIS(SATE)phosphotriester and 3′-azido-2′,3′-dideoxythymidine

It is shown that ddA bis(SATE)phosphotriester is one of the most potent anti-HIV agents in cell culture. Compared with the parent nucleoside, ddA, an increase of 3 orders of magnitude was observed in the EC50, which makes this compound as active as AZT. This can be tentatively explained if one considers that direct ddAMP intracellular delivery shunts the well established ddA/ddI metabolism pathway.

Susceptibility of recombinant porcine endogenous retrovirus reverse transcriptase to nucleoside and non-nucleoside inhibitors

Abstract. Transplantation of organs, tissues or cells from pigs to humans could be a potential solution to the shortage of human organs for transplantation. Porcine endogenous retroviruses (PERVs) remain a major safety concern for porcine xenotransplantation. Thus, finding drugs that could be used as virological prophylaxis (or therapy) against PERV replication would be desirable. One of the most effective ways to block retroviral multiplication is to inhibit the enzyme reverse transcriptase (RT) which catalyzes the reverse transcription of viral RNA to proviral double-stranded DNA. We report here the cloning and expression of PERV RT and its susceptibility to several inhibitors. Our data demonstrate PERV susceptibility in vitro to the triphosphorylated nucleoside analog of zidovudine (AZT) and to ddGTP and to a lesser extent to ddTTP but almost no susceptibility to the non-nucleoside RT inhibitors tested.

One‐round determination of seven leukocyte subsets in Rhesus macaque blood by flow cytometry

BACKGROUNDnRhesus macaques are frequently used in biomedical research as experimental models for studying infectious diseases and for preclinical vaccination trials. The infection of these monkeys with simian immunodeficiency viruses (SIV) or simian-human immunodeficiency viruses (SHIV) reproduces the clinical and immunological characteristics of human infection by human immunodeficiency virus (HIV). Evolution of the immune response in the infected animals is generally analyzed by determining the lymphocyte subsets on blood samples using flow cytometry but requiring multiple, blood consuming, determinations.nnnMETHODSnCell subsets present in whole-blood samples were labeled with a combination of anti-human monoclonal antibodies to CD2, CD20, CD4, CD8, and CD14 coupled to FITC or PE and analyzed by flow cytometry.nnnRESULTSnIn one round, we obtained the precise determination of macaque blood cell composition by flow cytometry. Monocytes, granulocytes, eosinophils, B lymphocytes, helper, and cytotoxic T lymphocytes were distinguished. Results obtained correlated strongly with those obtained with conventional blood cell differential systems and with separate staining of lymphocytes. The analysis of blood from healthy rhesus macaques and SHIV-infected animals demonstrated the accuracy of the determination even in very pathological situations such as macaques with simian AIDS.nnnCONCLUSIONSnOur method allows fast determination of the blood cell composition and will be particularly useful to evaluate the cell subset evolution of macaques involved in large-scale experimental trials.

Total synthesis of a Pepstatin analogue incorporating two trifluoromethyl hydroxymethylene isosteres

Abstract The total synthesis of a trifluoromethyl (Tfm) analogue of the aspartate protease inhibitor Pepstatin has been accomplished via incorporation of two α-Tfm-amino β-hydroxy peptide isosteres instead of the natural statine units. The title compound as well as several Tfm-substituted precursors did not show anti-HIV activity.

Synthesis and Antiviral Evaluation of Pyrazinones Substituted with Acyclic Chains.

The synthesis of a series of pyrazine analogues of the anti-herpes compound, acyclovir is described. These syntheses were accomplished by various methods: in the presence of a Lewis acid or NaH for hydroxyethoxymethyl and hydroxybutyl groups or by sequential oxidation/reduction of 1-(beta-D-ribofuranosyl)-2-pyrazinones for 2,3-acyclonucleosides. Antiviral (HSV-1, CMV, Cox B4, HIV-1) properties of these compounds were determined.

Increase of the adenallene anti-HIV activity in cell culture using its bis(tBuSATE) phosphotriester derivative

The bis(S-pivaloyl-2-thioethyl) phosphotriester derivative of 9-(4-hydroxy-1,2-butadienyl)adenine (adenallene) was synthesized. This mononucleotide prodrug proved to be more effective than the parent nucleoside in inhibiting HIV-1 replication in several human T4 lymphoblastoid cell lines.

bis(S-Acyl-2-thioethyl)esters of 2′,3′-Dideoxyadenosine 5′-Monophosphate Are Potent Anti-HIV Agents in Cell Culture

Abstract It is shown that ddA bis(SATE)phosphotriesters have potent anti-HIV activity in cell culture. Thus, compared with the parent nucleoside, a decrease of 3 or 4 orders of magnitude was observed in the EC50 values for the bis(S-acetyl-2-thioethyl)phosphotriester derivative, which makes this compound as active as AZT.

Potential Antiviral Agents. Part II. Synthesis and Antiviral Evaluation of Pyrazinones Substituted With Acyclic Chains

The synthesis of a series of 4-substituted hydroxybutyl pyrazine analogues of the anti-herpes compound, acyclovir, is described. The compounds were characterized with 1H and 13C nmr, mass and IR spectroscopy. Antiviral (HSV-1, CMV, Cox B4, HIV-1) properties of these compounds were examined. None of these compounds were active against these viruses.

New Acyclonucleosides: Synthesis and Anti-HIV Activity

The synthesis of new acyclic nucleosides is described. These syntheses were accomplished by various methods: glycosylation, selective or total deprotection, oxidation/reduction, chlorination or azidation of hydroxyl groups. The compounds were characterized with NMR, mass and IR spectroscopy. Antiviral properties of these compounds were evaluated on HIV-1 infected cell lines.