RESUMO
The synthesis and in vitro anti-HIV activity of a novel series of pronucleotides are reported. These prodrugs were characterized by a phosphorodithiolate structure, incorporating two O-pivaloyl-2-oxyethyl substituents as biolabile phosphate protections. The compounds were obtained following an original one-pot three-step procedure, involving the formation of a phosphorodithioite intermediate which is in situ oxidized. In vitro, comparative anti-HIV evaluations demonstrate that such original prodrugs are able to allow the efficient intracellular release of the corresponding 5'-mononucleotide. The pronucleotide of 2',3'-dideoxyadenosine (ddA) 3 exhibited a very potent antiretroviral effect with 50% effective concentration (EC50) values in nanomolar concentration range in various cell lines. In primary monocytes/macrophages, this derivative was 500 times more potent in inhibiting HIV replication (EC50 0.23 pM) than ddA and the selectivity index of the prodrug is fifty times higher than the one of the parent nucleoside.
Assuntos
Fármacos Anti-HIV/farmacologia , HIV-1/efeitos dos fármacos , Nucleosídeos/farmacologia , Pró-Fármacos/farmacologia , Compostos de Sulfidrila/farmacologia , Fármacos Anti-HIV/síntese química , Fármacos Anti-HIV/química , Células Cultivadas , Relação Dose-Resposta a Droga , Humanos , Testes de Sensibilidade Microbiana , Estrutura Molecular , Nucleosídeos/síntese química , Nucleosídeos/química , Pró-Fármacos/síntese química , Pró-Fármacos/química , Relação Estrutura-Atividade , Compostos de Sulfidrila/síntese química , Compostos de Sulfidrila/química , Replicação Viral/efeitos dos fármacosRESUMO
Infection of primates by HIV-1 and SIV induces multiple hematological abnormalities of central hematopoietic origin. Although these defects greatly contribute to the pathophysiology of HIV-1 infection, the molecular basis for altered BM function remains unknown. Here we show that when cynomolgus macaques were infected with SIV, the multipotent potential of their hematopoietic progenitor cells was lost, and this correlated with downregulation of STAT5A and STAT5B expression. However, forced expression of STAT5B entirely rescued the multipotent potential of the hematopoietic progenitor cells. In addition, an accessory viral protein required for efficient SIV and HIV replication and pathogenicity, "Negative factor" (Nef), was essential for SIV-mediated impairment of the multipotent potential of hematopoietic progenitors ex vivo and in vivo. This newly uncovered property of Nef was both conserved between HIV-1 and SIV strains and entirely dependent upon the presence of PPARgamma in targeted cells. Further, PPARgamma agonists mimicked Nef activity by inhibiting STAT5A and STAT5B expression and hampering the functionality of hematopoietic progenitors both ex vivo and in vivo. These findings have extended the role of Nef in the pathogenicity of HIV-1 and SIV and reveal a pivotal role for the PPARgamma/STAT5 pathway in the regulation of early hematopoiesis. This study may provide a basis for investigating the potential therapeutic benefits of PPARgamma antagonists in both patients with AIDS and individuals with hematopoietic disorders.
Assuntos
Produtos do Gene nef/metabolismo , HIV-1/metabolismo , Hematopoese/fisiologia , PPAR gama/metabolismo , Fator de Transcrição STAT5/metabolismo , Transdução de Sinais/fisiologia , Vírus da Imunodeficiência Símia/metabolismo , Sequência de Aminoácidos , Animais , Feminino , Produtos do Gene nef/genética , HIV-1/genética , Doenças Hematológicas/metabolismo , Doenças Hematológicas/fisiopatologia , Células-Tronco Hematopoéticas/citologia , Células-Tronco Hematopoéticas/fisiologia , Humanos , Células K562 , Macaca fascicularis , Masculino , Dados de Sequência Molecular , PPAR gama/genética , Fator de Transcrição STAT5/genética , Vírus da Imunodeficiência Símia/genéticaRESUMO
Sexual transmission is the major route of HIV-1 infection worldwide. Dendritic cells (DCs) from the mucosal layers are considered to be the initial targets of HIV-1 and probably play a crucial role in HIV-1 transmission. We investigated the role of cell-to-cell contact between HIV-1-exposed immature DCs and various lymphocyte subsets in the stimulation of HIV-1 replication. We found that HIV-1 replication and production in DCs were substantially enhanced by the coculture of DCs with primary CD4 T or nonpermissive B lymphocytes but not with primary activated CD8 T lymphocytes or human transformed CD4 T lymphocytes. Most of the new virions released by cocultures of HIV-1-exposed immature DCs and primary B lymphocytes expressed the DC-specific marker CD1a and were infectious for both immature DCs and peripheral blood mononuclear cells (PBMCs). Cocultured DCs thus produced large numbers of infectious viral particles under these experimental conditions. The soluble factors present in the supernatants of the cocultures were not sufficient to enhance HIV-1 replication in DCs, for which cell-to-cell contact was required. The neutralizing monoclonal antibody IgG1b12 and polyclonal anti-HIV-1 sera efficiently blocked HIV-1 transfer to CD4 T lymphocytes but did not prevent the increase in viral replication in DCs. Neutralizing antibodies thus proved to be more efficient at blocking HIV-1 transfer than previously thought. Our findings show that HIV-1 exploits DC-lymphocyte cross talk to upregulate replication within the DC reservoir. We provide evidence for a novel mechanism that may facilitate HIV-1 replication and transmission. This mechanism may favor HIV-1 pathogenesis, immune evasion, and persistence.
Assuntos
Linfócitos B/imunologia , Linfócitos T CD4-Positivos/imunologia , Células Dendríticas/virologia , HIV-1/fisiologia , Liberação de Vírus , Replicação Viral , Células Cultivadas , Técnicas de Cocultura , Células Dendríticas/imunologia , HIV-1/crescimento & desenvolvimento , HumanosRESUMO
The synthesis and in vitro anti-HIV activity of a novel series of phosphoramidate pronucleotides including a S-pivaloyl-2-thioethyl (tBuSATE) group as biolabile phosphate protecting group are reported. Such constructs, obtained through different phosphorus chemistries, are characterized by the association of two different anti-HIV nucleoside analogues linked to the phosphorus atom respectively by the sugar residue and the exocyclic amino function of the nucleobase. In vitro, comparative anti-HIV evaluation demonstrates that such original prodrugs are able to allow the efficient intracellular combination release of a 5'-mononucleotide as well as another nucleoside analogue. In human T4-lymphoblastoid cells, the pronucleotide 1 shows remarkable antiviral activity with an EC50 in the nanomolar range (0.6 ηM) and without additional cytotoxicity. In addition, these two pronucleotide models exhibit higher selectivity index than the equimolar mixture of their constitutive nucleoside analogues opening the way to further studies with regard to the current use of drug combinations.
Assuntos
Nucleotídeos/química , Fármacos Anti-HIV/química , Fármacos Anti-HIV/metabolismo , Fármacos Anti-HIV/farmacologia , Antivirais/química , Antivirais/metabolismo , Antivirais/farmacologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Portadores de Fármacos/química , HIV-1/efeitos dos fármacos , Humanos , Nucleotídeos/metabolismo , Nucleotídeos/farmacologia , Pró-Fármacos/química , Pró-Fármacos/metabolismo , Pró-Fármacos/farmacologiaRESUMO
Nine anionic water-soluble calix[4]arene species, incorporating sulfonate, carboxylate or phosphonate groups, six of them incorporating two 2,2'-bithiazole subunits in alternate position at the lower rim, have been synthesised and evaluated as anti-HIV agents on various HIV strains and cells of the lymphocytic lineage (HIV-1 III B/MT4, HIV-1 LAI/CEM-SS, HIV-1 Bal/PBMC), using AZT as reference compound. A toxicity was detected for a minority of compounds on PBMC whereas for the others no cellular toxicity was measured at concentrations up to 100 microM. Most of the compounds have an antiviral activity in a 10-50 microM range, and one of them, sulfonylated, displays its activity, whatever the tropism of the virus, at a micromolar concentration.
Assuntos
Fármacos Anti-HIV/farmacologia , Calixarenos/farmacologia , Infecções por HIV/tratamento farmacológico , HIV-1/efeitos dos fármacos , Tiazóis/farmacologia , Fármacos Anti-HIV/síntese química , Fármacos Anti-HIV/química , Calixarenos/síntese química , Calixarenos/química , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Humanos , Leucócitos Mononucleares/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Estrutura Molecular , Tiazóis/síntese química , Tiazóis/química , Água/químicaRESUMO
Poly(L-lysine citramide) is a degradable bioresorbable polyanion whose polyamide chains are composed of citric acid and L-lysine building blocks. Its chemical and physicochemical properties were extensively investigated in the past for its interest as polymeric drug carrier. In this work, 4(S)-amino-3-(S)-hydroxy-5-phenylpentanoyl-isoleucyl-phenylalanine methyl ester, a pseudopeptide active against the HIV protease in vitro, was linked to poly(L-lysine citramide) in attempts to promote solubility and cell penetration. Conjugates were characterized by FTIR, NMR, SEC, DLS, amino-acid analyses, and toxicity in mice. They degraded slowly at pH 7.4 and more rapidly at pH 4.5, two pH values selected to mimic extra-cellular fluids and intralysosome medium, respectively. According to capillary zone electrophoresis, degradation did not release the peptide. The phenylalanyl-isoleucyl-phenylalanine methyl ester peptide, inactive against the protease in vitro, was used as negative control. The anti-HIV activities of the carrier, of the conjugates and of model molecules, including a fluorescence-labeled pseudopeptide conjugate, were evaluated comparatively in vitro using two cell lines, namely, CEM-SS and MT-4 cells, infected with HIV-1 LAI and IIIB isolates, respectively. Unexpectedly, all the conjugates showed in vitro antiviral activity independent of peptide release and of inhibition of the HIV protease. According to FACS analysis, the antiviral activity was related to the presence of peptide moieties along the polymer chains and depended on the order by which cells, viruses, and conjugates were presented to each other. Although it was not possible to determine whether the antiviral activity resulted from interactions between conjugates and cells or conjugates and virus or both, the conjugates appeared able to inhibit the binding of the virus to cells in vitro when introduced before cell infection. None of the conjugates exhibited acute toxicity in mice.
Assuntos
Fármacos Anti-HIV/farmacologia , Infecções por HIV/tratamento farmacológico , HIV-1/efeitos dos fármacos , Linfócitos/efeitos dos fármacos , Fragmentos de Peptídeos/farmacologia , Polilisina/análogos & derivados , Animais , Fármacos Anti-HIV/química , Peso Corporal/efeitos dos fármacos , Linhagem Celular , Cromatografia em Camada Fina , Ensaio de Imunoadsorção Enzimática , Feminino , Citometria de Fluxo , Inibidores da Protease de HIV/química , Inibidores da Protease de HIV/farmacologia , HIV-1/metabolismo , Humanos , Concentração Inibidora 50 , Linfócitos/citologia , Linfócitos/metabolismo , Lisina/química , Espectroscopia de Ressonância Magnética , Camundongos , Fragmentos de Peptídeos/química , Polilisina/química , Polilisina/farmacologia , Polímeros , Espectroscopia de Infravermelho com Transformada de FourierRESUMO
A new anti-HIV cyclodepsipeptide, homophymine A, was isolated from a New Caledonian collection of the marine sponge Homophymia sp. The structure of homophymine A was determined by interpretation of spectroscopic data, acid hydrolysis, and LC-MS analysis. Homophymine A contains 11 amino acid residues and an amide-linked 3-hydroxy-2,4,6-trimethyloctanoic acid moiety. Along with four D-, two L-, and one N-methyl amino acids, it also contains four unusual amino acid residues: (2S,3S,4R)-3,4-diMe-Gln, (2R,3R,4S)-4-amino-2,3-dihydroxy-1,7-heptandioic acid, L-ThrOMe, and (2R,3R,4R)-2-amino-3-hydroxy-4,5-dimethylhexanoic acid. In a cell-based XTT assay, homophymine A exhibited cytoprotective activity against HIV-1 infection with a IC50 of 75 nM.
Assuntos
Fármacos Anti-HIV/química , Depsipeptídeos/química , Poríferos/química , Animais , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Estrutura Molecular , Espectrometria de Massas por Ionização por ElectrosprayRESUMO
Synthesis, in vitro anti-HIV activity, stability studies as well as potential for oral absorption of some novel phenyl S-acyl-2-thioethyl (SATE) phosphotriester derivatives of AZT (zidovudine; 3'-azido-2',3'-dideoxythymidine) are described herein. These pronucleotides are characterized by the presence of polar functions on the SATE biolabile phosphate protections. Whereas derivatives incorporating an amino residue in the vicinity of the thioester functionality display low chemical stability, the introduction of one or two hydroxyl groups on the SATE moieties confers high resistance of the resulting prodrugs towards esterase hydrolysis. Thus, one of these pronucleotides, the monohydroxylated SATE derivative of AZT 2, is able to cross a Caco-2 cell monolayer mainly in intact form, probing that further development is warranted as a possible HIV-pronucleotide candidate.
Assuntos
Fármacos Anti-HIV/química , Fármacos Anti-HIV/farmacologia , Zidovudina/química , Zidovudina/farmacologia , Células CACO-2 , Humanos , Estrutura Molecular , Relação Estrutura-AtividadeRESUMO
In an approach to improve the pharmacological properties and pharmacokinetic profiles of the current protease inhibitors (PIs) used in clinics, and consequently, their therapeutic potential, we performed the synthesis of PI-spacer-valine prodrugs (PI=saquinavir, nelfinavir and indinavir; spacer=-C(O)(CH(2))(5)NH-), and evaluated their in vitro stability with respect to hydrolysis, anti-HIV activity, cytotoxicity, and permeation through a monolayer of Caco-2 cells (used as a model of the intestinal barrier), as compared with their parent PI and first generation of valine-PIs (wherein valine was directly connected through its carboxyl to the PIs). The PI-spacer-valine conjugates were prepared in two steps, in good yields, by condensing an acid derivative of the appropriate protected valine-spacer moiety with the PI, followed by deprotection of the valine protecting group. With respect to hydrolysis, we found that the PI-spacer-valine prodrugs were chemically more stable than the first generation of PI-Val prodrugs. Their stabilities correlated with the low to very low in vitro anti-HIV activity measured for those prodrugs wherein the coupling of valine-spacer residue to the PIs was performed onto the peptidomimetic PI's hydroxyl. Prodrugs wherein the coupling of the valine-spacer residue was performed onto the non-peptidomimetic PI hydroxyl displayed a higher antiviral activity, indicating that these prodrugs are also to some extent anti-HIV drugs by themselves. While the direct conjugation of L-valine to the PIs constituted a most appealing alternative, which improved their absorptive diffusion across Caco-2 cell monolayers and reduced their recognition by efflux carriers, its conjugation to the PIs through the -C(O)(CH(2))(5)NH- spacer was found to inhibit their absorptive and secretory transepithelial transport. This was attributable to a drastic reduction of their passive permeation and/or active transport, indicating that the PI-spacer-valine conjugates are poor substrates of the aminoacid carrier system located at the brush border side of the Caco-2 cell monolayer.
Assuntos
Inibidores da Protease de HIV/síntese química , Inibidores da Protease de HIV/farmacologia , Pró-Fármacos/síntese química , Pró-Fármacos/farmacologia , Valina/química , Cromatografia Líquida de Alta Pressão , Avaliação Pré-Clínica de Medicamentos , Estabilidade de Medicamentos , Técnicas In Vitro , Espectroscopia de Ressonância Magnética , Pró-Fármacos/químicaRESUMO
The kissing-loop complex that initiates dimerization of genomic RNA is crucial for Human Immunodeficiency Virus Type 1 (HIV-1) replication. We showed that owing to its strong similitude with the bacterial ribosomal A site it can be targeted by aminoglycosides. Here, we present its crystal structure in complex with neamine, ribostamycin, neomycin and lividomycin. These structures explain the specificity for 4,5-disubstituted 2-deoxystreptamine (DOS) derivatives and for subtype A and subtype F kissing-loop complexes, and provide a strong basis for rational drug design. As a consequence of the different topologies of the kissing-loop complex and the A site, these aminoglycosides establish more contacts with HIV-1 RNA than with 16S RNA. Together with biochemical experiments, they showed that while rings I, II and III confer binding specificity, rings IV and V are important for affinity. Binding of neomycin, paromomycin and lividomycin strongly stabilized the kissing-loop complex by bridging the two HIV-1 RNA molecules. Furthermore, in situ footprinting showed that the dimerization initiation site (DIS) of HIV-1 genomic RNA could be targeted by these aminoglycosides in infected cells and virions, demonstrating its accessibility.
Assuntos
Aminoglicosídeos/química , Fármacos Anti-HIV/química , HIV-1/genética , RNA Viral/química , Sítios de Ligação , Linhagem Celular , Cristalografia por Raios X , Dimerização , Sistemas de Liberação de Medicamentos , Humanos , Modelos Moleculares , Vírion/químicaRESUMO
Active site of reverse transcriptase contains carboxylate groups involved in the magnesium binding. We prepared some nucleoside analogs which could bind to these carboxylates preventing the binding of nucleotides. To the 3'-amino-3'-deoxy-thymidine, different N-protected omega-amino-acids were bound, the protection removed to give the 3'-(omega-amino-acyl-) amino-3'-deoxy-thymidines in good yield. Some showed moderate to low activity in HIV 1 replication test.
Assuntos
Transcriptase Reversa do HIV/antagonistas & inibidores , Transcriptase Reversa do HIV/química , Timidina/análogos & derivados , Antineoplásicos/síntese química , Antineoplásicos/química , Antineoplásicos/farmacologia , Domínio Catalítico , Linhagem Celular Tumoral , Desenho de Fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Transcriptase Reversa do HIV/metabolismo , HIV-1/efeitos dos fármacos , HIV-1/fisiologia , Humanos , Magnésio/metabolismo , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacologia , Timidina/síntese química , Timidina/farmacologia , Replicação Viral/efeitos dos fármacosRESUMO
The overcoming of antiviral drug resistance is an important challenge in the treatment of HIV-1 infection. According to the theory of viral error catastrophe, slightly increasing the mutation rate could exceed the error threshold for viability of a viral population and kill it. Investigation of this mechanism could lead to the discovery of new antiviral agents capable of bypassing viral resistance. To this aim, we designed several modified nucleosides. We describe here the synthesis and partial evaluation of 8-amido-2'-deoxyadenosine. The supplementary amide group on the base should allow base-pairing with several natural nucleosides, thus creating supplementary mutations that would kill the virus.
Assuntos
Fármacos Anti-HIV/síntese química , Fármacos Anti-HIV/farmacologia , HIV-1/efeitos dos fármacos , Fármacos Anti-HIV/química , Desoxiadenosinas/síntese química , Desoxiadenosinas/química , Desoxiadenosinas/farmacologia , Desenho de Fármacos , Farmacorresistência Viral/genética , HIV-1/genética , HIV-1/fisiologia , Humanos , Testes de Sensibilidade Microbiana , Replicação Viral/efeitos dos fármacosRESUMO
This article describes the synthesis of a series of AZT analogues bearing an acyclic chain between the sugar and the base moieties is described. These new compounds were readily obtained using microwave irradiation. The compounds were characterized by (1)H NMR and IR spectroscopy. Antiviral (HIV-1) properties of these compounds were examined.
Assuntos
Antivirais/química , Nucleosídeos/química , Zidovudina/química , Antivirais/síntese química , Antivirais/farmacologia , Linhagem Celular Transformada , Sobrevivência Celular/efeitos dos fármacos , HIV-1/efeitos dos fármacos , Humanos , Modelos Químicos , Estrutura Molecular , Zidovudina/síntese química , Zidovudina/farmacologiaRESUMO
The aim of this study was to characterize the potent nonimmunoglobulin (Ig) inhibitory activity defected in plasma from some HIV-infected, efavirenz (EFV)-treated patients. Concentration of EFV in plasma was measured by HPLC and correlation with reverse transcriptase (RT) inhibition or decrease in virus replication in cellular assays was searched. After plasma protein elimination by ethanol extraction, an inhibitory activity is measurable on RT in vitro that correlates with EFV concentration determined by HPLC. However, total plasma-containing EFV does not inhibit RT activity in cell-free assay, but it does efficiently inhibit virus replication in cell culture assays. Thus, despite being bound to plasma proteins (retention of EFV after extensive dialysis), EFV in plasma conserves its antiviral activity on infected cells. This observation precludes the use of crude sera and plasmas from EFV-treated patients for the study of antibody-mediated neutralizing activity.
Assuntos
HIV/efeitos dos fármacos , Oxazinas/farmacologia , DNA Polimerase Dirigida por RNA/efeitos dos fármacos , Inibidores da Transcriptase Reversa/farmacologia , Replicação Viral/efeitos dos fármacos , Alcinos , Benzoxazinas , Proteínas Sanguíneas/química , Proteínas Sanguíneas/metabolismo , Técnicas de Cultura de Células , Ciclopropanos , Humanos , Imunoglobulina G/sangue , Leucócitos Mononucleares/virologia , Oxazinas/sangue , Oxazinas/metabolismo , Ligação Proteica , DNA Polimerase Dirigida por RNA/metabolismo , Inibidores da Transcriptase Reversa/sangueRESUMO
With the view to deliver anti-HIV nucleoside and nucleoside-monophosphate (MP) analogues specifically into HIV-infected cells, we synthesized a series of ester and phosphoramidate peptide conjugates of zidovudine (AZT) and of AZT-MP, respectively, wherein the peptide sequences derive from a HIV-protease (PR) hydrolysable substrate. Their in vitro stability with respect to hydrolysis, anti-HIV activity and cytotoxicity, and ability to inhibit the HIV-PR activity were investigated. Concerning the ester AZT-peptide conjugates, their antiviral activity level in thymidine kinase-expressing (TK+) CEM-SS and MT-4 cells was in most cases closely correlated to their hydrolysis rate: the faster the hydrolysis, the closer the anti-HIV activity to that of AZT. None of them was a HIV-PR substrate, indicating that their antiviral activity was not related to their intracellular hydrolysis by this enzyme. None of them inhibited HIV in TK-deficient (TK-) CEM cells, demonstrating that they probably act as prodrugs of AZT. Most of the phosphoramidate peptide conjugates of AZT-MP were rapidly degraded in a physiological buffer into several metabolites including AZT. Their anti-HIV activity in TK+ CEM-SS and MT-4 cells was much lower than that of AZT, indicating that only low amounts of AZT or AZT-MP were released into cells during incubation. Antiviral activities measured on TK- CEM cells for some phosphoramidates suggest that low amounts of AZT-MP could be released intracellularly. However, this AZT-MP release was not initiated by a HIV-PR hydrolysis, as no evidence for peptide cleavage was obtained by HPLC analysis of one representative compound after incubation with HIV-PR.
Assuntos
Sistemas de Liberação de Medicamentos , Infecções por HIV/tratamento farmacológico , Protease de HIV/química , Pró-Fármacos , Nucleotídeos de Timina/síntese química , Nucleotídeos de Timina/uso terapêutico , Zidovudina/análogos & derivados , Zidovudina/síntese química , Zidovudina/uso terapêutico , Amidas/síntese química , Fármacos Anti-HIV/síntese química , Fármacos Anti-HIV/uso terapêutico , Células Cultivadas , Didesoxinucleotídeos , Avaliação de Medicamentos , Estabilidade de Medicamentos , Ésteres/síntese química , Protease de HIV/efeitos dos fármacos , HIV-1/efeitos dos fármacos , Humanos , Concentração Inibidora 50 , Modelos Biológicos , Ácidos Fosfóricos/síntese química , Pró-Fármacos/síntese química , Pró-Fármacos/uso terapêutico , Inibidores de Proteases/farmacologia , Timidina Quinase/genéticaRESUMO
BACKGROUND: An attenuated immunodeficiency virus has been long considered innocuous. Nevertheless, converging data suggest that low levels of viral replication can still provoke AIDS. Pathogenesis of these attenuated infections is not understood. OBJECTIVES: To determine the pathogenicity of a long-term attenuated infection and to delineate T-cell dynamics during such an infection. METHODS: This is a cross-sectional study of 12 rhesus macaques infected with SIV Delta nef for 8 years. We evaluated apoptosis (annexin V), activation (HLA-DR, Ki67), and newly generated T cells (TCR excision circle: TREC). RESULTS: Infection with SIV Delta nef induced pathological CD4 T-cell depletion after 8 years of infection. Virus replication and CD8 T-cell activation positively correlated with the rate of disease progression. The frequency of TREC within CD8+CD45RA+ cells increased in SIV Delta nef-infected animals compared to age-matched non-infected controls. Moreover, in the cohort of infected animals, TREC+CD45RA+CD4+ T-cell counts correlated strongly with non-progression to AIDS. The animal with the lowest rate of disease progression exhibited a 115-fold increase in TREC+CD45RA+CD4+ T-cell counts compared to age-matched non-infected controls. In contrast, the animal showing the fastest rate of progression to AIDS displayed 600-fold lower TREC+CD45RA+CD4+ T-cell counts compared to age-matched non-infected controls. CONCLUSIONS: Our results suggest that the thymus plays a major role in the pathogenesis of an attenuated SIV infection and that a sustained thymic output could maintain CD4 T-cell homeostasis in the context of low viral loads.
Assuntos
Síndrome de Imunodeficiência Adquirida dos Símios/virologia , Vírus da Imunodeficiência Símia/fisiologia , Animais , Apoptose , Contagem de Linfócito CD4 , Relação CD4-CD8 , Linfócitos T CD8-Positivos , Proliferação de Células , Progressão da Doença , Produtos do Gene nef , Rearranjo Gênico do Linfócito T , Antígenos Comuns de Leucócito/análise , Ativação Linfocitária , Macaca mulatta , Síndrome de Imunodeficiência Adquirida dos Símios/imunologia , Fatores de Tempo , Carga Viral , Replicação ViralRESUMO
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.
Assuntos
Fármacos Anti-HIV/síntese química , HIV-1 , Nucleosídeos/síntese química , Replicação Viral/efeitos dos fármacos , Fármacos Anti-HIV/química , Fármacos Anti-HIV/farmacologia , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Humanos , Nucleosídeos/química , Nucleosídeos/farmacologiaRESUMO
OBJECTIVE: The acute phase of HIV and SIV infections leads to a host/virus equilibrium, and accumulating evidence suggests that this early phase dictates further progression towards AIDS. To gain insight into the early events that determine rapid disease progression, we performed a longitudinal study in the SIV rhesus macaque model, allowing an in-depth analysis of the primary stage of infection. METHODS: We assessed viral replication (quantification of replicating and infected cells in lymph nodes, plasma viral load), immune response (cytotoxic T lymphocyte, antibody, proliferative responses), apoptosis and cycling cells (Ki-67 labelling) on lymph nodes and blood in nine rhesus macaques infected with the pathogenic SIVmac251 isolate. RESULTS: Six primates remained asymptomatic during the one year follow-up period of the study, whereas three developed AIDS within 5-6 months. During the first 2 weeks of infection, peak numbers of apoptotic cells in the lymph node T-cell areas were significantly higher in the three future rapid progressors than in the six future slow progressors, and were correlated with subsequent viraemia levels measured 6 months after infection. The numbers of infected or cycling cells in the same lymph node T-cell areas, however, only became significantly different in future rapid and slow progressors 8 weeks after infection, at the end of the primary phase. CONCLUSION: Our findings identified extensive apoptosis induction in peripheral lymphoid organs as an early and predictive event that may play a crucial role in impairing the capacity of the immune system to control viral replication and progression towards disease.
Assuntos
Linfonodos/virologia , Síndrome de Imunodeficiência Adquirida dos Símios/virologia , Vírus da Imunodeficiência Símia/fisiologia , Doença Aguda , Animais , Apoptose , Biomarcadores/análise , Ciclo Celular , Divisão Celular , Progressão da Doença , Antígeno Ki-67/análise , Linfonodos/patologia , Macaca mulatta , Linfócitos T Citotóxicos/imunologia , Viremia , Replicação ViralRESUMO
Herein, we report the design, synthesis, and biological effects of nucleosides bearing a disulfide function on the sugar ring as prodrugs of potentially active mercaptonucleotides that can target ribonucleotide reductase or reverse transcriptase. We show that cytidine derivatives efficiently reduce dNTP pools in human CEM/SS cells and that 3'-deoxythymidin-3'-yl methyl disulfide is able to interfere with both cellular dNTP synthesis and HIV reverse transcription.
Assuntos
Fármacos Anti-HIV/síntese química , Desoxirribonucleosídeos/síntese química , Dissulfetos/síntese química , Pró-Fármacos/síntese química , Inibidores da Transcriptase Reversa/síntese química , Ribonucleotídeo Redutases/antagonistas & inibidores , Estavudina/síntese química , Animais , Fármacos Anti-HIV/química , Fármacos Anti-HIV/farmacologia , Divisão Celular/efeitos dos fármacos , Células Cultivadas , Desoxirribonucleosídeos/química , Desoxirribonucleosídeos/farmacologia , Dissulfetos/química , Dissulfetos/farmacologia , HIV-1/efeitos dos fármacos , HIV-2/efeitos dos fármacos , Humanos , Camundongos , Pró-Fármacos/química , Pró-Fármacos/farmacologia , Inibidores da Transcriptase Reversa/química , Inibidores da Transcriptase Reversa/farmacologia , Estavudina/análogos & derivados , Estavudina/química , Estavudina/farmacologia , Relação Estrutura-Atividade , Linfócitos T/citologia , Linfócitos T/efeitos dos fármacosRESUMO
The synthesis and in vitro anti-HIV activity of phosphoramidate diester derivatives of 3'-azido-2',3'-dideoxythymidine (AZT) bearing one S-pivaloyl-2-thioethyl (tBuSATE) group and various amino residues are reported. These compounds were obtained from an H-phosphonate strategy using an amidative oxidation step. Most of these derivatives appeared to inhibit HIV-1 replication, with EC(50) values at micromolar concentration in thymidine kinase-deficient (TK-) cells, revealing a less restrictive intracellular decomposition process than previously reported for other phosphoramidate prodrugs. The proposed decomposition pathway of this new series of mixed pronucleotides may successively involve an esterase and a phosphoramidase hydrolysis.