During the last two decades, progresses in bioimaging and the development of various strategies to fluorescently label the viral components opened a wide range of possibilities to visualize the early phase of Human Immunodeficiency Virus 1 (HIV-1) life cycle directly in infected cells. After fusion of the viral envelope with the cell membrane, the viral core is released into the cytoplasm and the viral RNA (vRNA) is retro-transcribed into DNA by the reverse transcriptase. During this process, the RNA-based viral complex transforms into a pre-integration complex (PIC), composed of the viral genomic DNA (vDNA) coated with viral and host cellular proteins. The protective capsid shell disassembles during a process called uncoating. The viral genome is transported into the cell nucleus and integrates into the host cell chromatin. Unlike biochemical approaches that provide global data about the whole population of viral particles, imaging techniques enable following individual viruses on a single particle level. In this context, quantitative microscopy has brought original data shedding light on the dynamics of the viral entry into the host cell, the cytoplasmic transport, the nuclear import, and the selection of the integration site. In parallel, multi-color imaging studies have elucidated the mechanism of action of host cell factors implicated in HIV-1 viral cycle progression. In this review, we describe the labeling strategies used for HIV-1 fluorescence imaging and report on the main advancements that imaging studies have brought in the understanding of the infection mechanisms from the viral entry into the host cell until the provirus integration step.
- MeSH
- buněčné jádro virologie MeSH
- fluorescenční mikroskopie MeSH
- HIV infekce virologie MeSH
- HIV-1 chemie genetika fyziologie MeSH
- integrace viru MeSH
- internalizace viru * MeSH
- lidé MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
In the present work we introduce a straightforward fluorescent assay that can be applied in studies of the transbilayer movement (flip-flop) of fluorescent lipid analogues across supported phospholipid bilayers (SPBs). The assay is based on the distance dependent fluorescence quenching by light absorbing surfaces. Applied to SPBs this effect leads to strong differences in fluorescence lifetimes when the dye moves from the outer lipid leaflet to the leaflet in contact with the support. Herein, we present the basic principles of this novel approach, and comment on its advantages over the commonly used methods for investigating flip-flop dynamics across lipid bilayers. We test the assay on the fluorescent lipid analog Atto633-DOPE and the 3-hydroxyflavone F2N12S probe in SPBs composed of DOPC/ DOPS lipids. Moreover, we compare and discuss the flip-flop rates of the probes with respect to their lateral diffusion coefficients.
- MeSH
- časové faktory MeSH
- chemické techniky analytické metody MeSH
- difuze MeSH
- fluorescence MeSH
- fluorescenční barviva chemie MeSH
- fosfatidylcholiny chemie MeSH
- fosfatidylethanolaminy chemie MeSH
- fosfatidylseriny chemie MeSH
- fosfolipidy chemie MeSH
- kinetika MeSH
- lipidové dvojvrstvy chemie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
