RESUMO
Despite their clinical and biological importance, the cell biology of obligate intracellular bacteria is less well understood than that of many free-living model organisms. One reason for this is that they are mostly genetically intractable. As a consequence, it is not possible to engineer strains expressing fluorescent proteins and therefore fluorescence light microscopy - a key tool in host-pathogen cell biology studies - is difficult. Strain diversity also limits the universality of antibody-based immunofluorescence approaches. Here, we have developed a universal labelling protocol for intracellular bacteria based on a clickable methionine analog. Whilst we have applied this to obligate intracellular bacteria, we expect it to be useful for labelling free living bacteria as well as other intracellular pathogens.
Assuntos
Alcinos/química , Bactérias/metabolismo , Glicina/análogos & derivados , Espaço Intracelular/microbiologia , Metionina/análogos & derivados , Coloração e Rotulagem/métodos , Bactérias/classificação , Bactérias/genética , Química Click/métodos , Glicina/química , Interações Hospedeiro-Patógeno/genética , Metionina/químicaRESUMO
Recombinant human immunodeficiency virus (HIV) infection was associated with exchange of sex for money, ≥1 sex partner within the prior 6 months, and decline in CD4 cell count in this Thai cohort study. These findings suggest that recombinant HIV infection may have implications for HIV disease progression, safer sex practices, and vaccine development.
Assuntos
Infecções por HIV/diagnóstico , HIV-1/genética , Recombinação Genética , Trabalho Sexual , Parceiros Sexuais , Adulto , Estudos de Coortes , Feminino , Infecções por HIV/epidemiologia , Infecções por HIV/virologia , HIV-1/isolamento & purificação , Humanos , Masculino , Dados de Sequência Molecular , Fatores de Risco , Análise de Sequência de DNA , Tailândia/epidemiologiaRESUMO
The pathogenic mechanism of the severe form of dengue is complicated. Recent reports indicate that apoptotic death of various tissues or organs may be associated with vascular leakage, and ultimately leads to the death of DENV-infected patients. In the present study, we provide additional evidence supporting the detrimental role of apoptosis in DENV infection. A comparison of the rate of apoptosis in PBMCs isolated from patients suffering DF, a mild form of the disease, and the rate in patients with DHF, a life-threatening disease, revealed that PBMCs from DHF patients underwent apoptosis at a significantly higher rate than those suffering from DF alone. This suggests that the severity of natural DENV infection correlates with PBMC apoptosis. In addition, this cell death was induced not only by DENV itself, but also by the apoptotic activities of pro-inflammatory cytokines, such as TNF-alpha, and IL-1beta, that were upregulated in DHF patients. The death of these mononuclear cells that function in an innate immune system may explain the higher viral load in DHF patients than in DF patients. Interestingly, a gene expression profile pattern elucidated that apoptosis occurring during natural DENV infection involved mainly the extrinsic apoptosis pathway, which is mediated via both caspase-dependent and caspase-independent mechanisms. In conclusion, our data highlight the adverse effect of apoptosis induced by DENV and by pro-inflammatory cytokines during natural DENV infection.