RESUMO
A microassay was developed to detect human herpesvirus 6 (HHV-6) binding to its cellular receptor using flow cytometry. Comparable results were obtained either by using HHV-6 preparations conjugated with fluorescein isothiocyanate or by indirect immunofluorescent labeling of membrane-bound virus using as primary antibody a monoclonal antibody specific for the HHV-6 gp60/110 envelope glycoprotein. Virus attachment to the plasma membrane was specific and saturable. As expected, among cell lines of various origin, maximum binding was detected on human T-lymphoid cells (HSB-2). Papain digestion of HSB-2 cells prevented HHV-6 attachment and reduced significantly virus infection, indicating the involvement of a protein-based receptor in the attachment step. After removal of the protease, virus receptors were resynthesized and their regeneration was prevented partially by cycloheximide, an inhibitor of protein synthesis. Unexpectedly, only high concentrations (mg/ml) of soluble heparan sulfate and heparin inhibited HHV-6 binding and infection. Under the same conditions, few micrograms (per ml) of heparin suppressed completely herpes simplex type 1 (HSV-1) attachment to the same cell line. Treatment of HSB-2 cells with heparitinase and heparinase, at doses that reduced significantly HSV-1 attachment, had little effect on HHV-6 binding to the cell membrane, indicating a different requirement of heparan sulfate-containing glycosaminoglycans for the two herpesviruses. These data suggest that protein components of the cellular membrane play an essential role in HHV-6 binding and infection while heparan sulfate-glycos-aminoglycans appear to be involved only partially in virus-receptor interaction.
Assuntos
Glicosaminoglicanos/fisiologia , Herpesvirus Humano 6/metabolismo , Linfócitos/virologia , Proteínas de Membrana/fisiologia , Receptores Virais/fisiologia , Animais , Metabolismo dos Carboidratos , Carboidratos/fisiologia , Linhagem Celular , Chlorocebus aethiops , Enzimas/metabolismo , Citometria de Fluxo/métodos , Glicosaminoglicanos/metabolismo , Humanos , Linfócitos/metabolismo , Proteínas de Membrana/metabolismo , Receptores Virais/biossíntese , Receptores Virais/metabolismo , Fatores de Tempo , Células Tumorais Cultivadas , Células VeroRESUMO
Acute myeloid leukemia with minimal signs of myeloid differentiation (AML-M0) is a recent addition to the FAB group classification. Chromosome data is scarce, but existing reports describe a high incidence of complex karyotypes and myelodysplastic syndrome-like chromosome alterations, while single chromosome translocations have rarely been reported. We describe the case of a 60-year-old woman diagnosed with AML-M0 with a novel translocation t(11;12)(q23-24;q24) as the sole karyotypic marker. Fluorescence in situ hybridization analysis to assess MLL gene splitting did not show rearrangement of this oncogene.
Assuntos
Cromossomos Humanos Par 11/genética , Cromossomos Humanos Par 12/genética , Leucemia Mieloide/genética , Leucemia Mieloide/patologia , Proto-Oncogenes , Fatores de Transcrição , Translocação Genética/genética , Doença Aguda , Diferenciação Celular , Bandeamento Cromossômico , Proteínas de Ligação a DNA/genética , Evolução Fatal , Feminino , Histona-Lisina N-Metiltransferase , Humanos , Hibridização in Situ Fluorescente , Cariotipagem , Leucemia Mieloide/tratamento farmacológico , Linfócitos/metabolismo , Pessoa de Meia-Idade , Síndromes Mielodisplásicas/genética , Proteína de Leucina Linfoide-Mieloide , RecidivaRESUMO
In a series of homo-isoflavonoids, chloro-substituted rac-3-benzylchroman-4-ones (3 d-f) showed an antiviral in vitro activity against selected picornaviruses. In order to study the anti-rhinovirus activity of each stereoisomer, racemic mixtures of 3 d and 3 e were successfully resolved by high-performance liquid chromatography, using a Whelk-O 1 column as chiral stationary phase. The CD spectra confirm that the two eluates of each compound are enantiomers but do not allow the assignment of their absolute configurations. The antiviral activity of the isomers and their racemates was tested in vitro against human rhinovirus serotype 1B and 14 infection, by means of the plaque reduction assay. All homoisoflavonoids tested exhibited an inhibitory effect on rhinovirus replication with an activity depending on virus serotype and compound. The two enantiomers of each compound and the corresponding racemate were equipotent, clearly showing that the configuration of the chiral center in position 3 does not influence the activity against both rhinovirus serotypes.
Assuntos
Antivirais/isolamento & purificação , Compostos de Benzil/isolamento & purificação , Isoflavonas/isolamento & purificação , Isoflavonas/farmacologia , Rhinovirus/efeitos dos fármacos , Antivirais/farmacologia , Compostos de Benzil/farmacologia , Relação Dose-Resposta a Droga , Células HeLa , Humanos , Estereoisomerismo , Ensaio de Placa ViralRESUMO
The in vitro antiviral activity against picornaviruses (rhinovirus serotype 1B and 14, and poliovirus type 2) of new synthetic 3-hydroxyflavones, 3-acetoxyflavones, and substituted cinnamic and benzoic acid flavon-3-yl esters was evaluated. The maximum non-toxic concentration of compounds was determined in a human cell line (HeLa) suitable for the replication of the three viruses. Their antiviral potency was measured by a plaque reduction assay. Generally, rhinoviruses exhibited a higher sensitivity to the new flavonoids than poliovirus. Flavones, with sterically small substituents in position 3, showed good activity against both rhinoviruses tested. However, the introduction of bulky substituents in the same position resulted in analogues with a higher toxicity and often with a lower efficacy.
