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It has always been necessary for researchers to visualisepathogenic microorganisms in their host cell's environment, inorder to define the host-pathogen interactions contributing toviral infections. Optical microscopy, combined with fluorescentlabels (such as GFP proteins and antibodies coupled with syntheticfluorophores), allows to showcase the specific structures of cells,including proteins. However, this approach is limited by its lowresolving power, which only helps distinguish cellular andmolecular structures at a scale of 200-300 nanometres (nm). Mostpathogenic viruses are of smaller sizes. Consequently, it isessential to resort to more precise imaging techniques, in order tobetter understand and define the internal structure of suchviruses. A study coordinated by Dr Christophe Zimmer (InstitutPasteur/CNRS), in collaboration with Dr Nathalie Arhel within thelab headed by Pr Pierre Charneau (Institut Pasteur/CNRS), showsthat the association of two recent imaging techniques helps obtainunique images of molecular assemblies of HIV-1 capsids, with aresolution around 10 times better than that of traditionalmicroscopes. This new approach, which uses super-resolution imagingand FlAsH labeling, does not affect the virus' ability toself-replicate. It represents a major step forward in molecularbiology studies, enabling the visualisation of microbial complexesat a scale of 30 nm without affecting their function. The newly developed approach combines super-resolution PALM imagingand fluorescent FlAsH labeling. PALM imaging relies on theacquisition of thousands of low-resolution images, each of whichshowing only a few fluorescent molecules. The molecular positionsare then calculated with high accuracy by computer programs andcompiled into a single high-resolution image. FlAsH labelinginvolves the insertion of a 6-amino-acid peptide into the proteinof interest. The binding of the FlAsH fluorophore to the peptidegenerates a fluorescent signal, thereby enabling the visualizationof the protein. For the first time, researchers have combined thesetwo methods in order to obtain high-resolution images of molecularstructures in either fixed or living cells. This new method has helped researchers visualise the AIDS Virus andlocalise its capsids in human cells, at a scale of 30 nm. Capsidsare conical structures which contain the HIV genome. Thesestructures must dismantle in order for the viral genome tointegrate itself into the host cell's genome. However, the timingof this disassembly has long been debated. According to aprevailing view, capsids disassemble right after infection of thehost cell and, therefore, do not play an important role in theintracellular transport of the virus to the host cell's nucleus.However, the results obtained by the researchers of the InstitutPasteur and CNRS indicate that numerous capsids remain unaltereduntil entry of the virus into the nucleus, confirming andstrengthening earlier studies based on electron microscopy. Hence,capsids could play a more important role than commonly assumed inthe replication cycle of HIV. The development of a new optical microscopy approach by theresearchers of the Institut Pasteur and CNRS offers uniqueperspectives for molecular biology. This new imaging techniquecould become a key tool in the study of numerous microbialcomplexes and their interactions with host cells at the molecularlevel. This non-invasive technique allows to observe proteinswithout destroying or altering their biological functions.Moreover, this technique could eventually enable the analysis ofmicroorganisms with single-nanometre accuracy, thereby ensuring atransition from microscopy to "nanoscopy". Consequently, the nextsteps are the sharing of this new approach with the scientificcommunity, its further development and its application to the studyof other pathogenic microorganisms. We are high quality suppliers, our products such as China Fractional Co2 Laser Machine , E-Light Laser Hair Removal for oversee buyer. To know more, please visits Ultrasonic Cavitation Slimming Machine.
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