Real-Time Visualization of HIV-1 GAG Trafficking in Infected Macrophages

Virus-Cell Interaction Section, HIV Drug Resistance Program, National Cancer Institute, Frederick, Maryland, USA.
PLoS Pathogens (Impact Factor: 7.56). 04/2008; 4(3):e1000015. DOI: 10.1371/journal.ppat.1000015
Source: PubMed


HIV-1 particle production is driven by the Gag precursor protein Pr55(Gag). Despite significant progress in defining both the viral and cellular determinants of HIV-1 assembly and release, the trafficking pathway used by Gag to reach its site of assembly in the infected cell remains to be elucidated. The Gag trafficking itinerary in primary monocyte-derived macrophages is especially poorly understood. To define the site of assembly and characterize the Gag trafficking pathway in this physiologically relevant cell type, we have made use of the biarsenical-tetracysteine system. A small tetracysteine tag was introduced near the C-terminus of the matrix domain of Gag. The insertion of the tag at this position did not interfere with Gag trafficking, virus assembly or release, particle infectivity, or the kinetics of virus replication. By using this in vivo detection system to visualize Gag trafficking in living macrophages, Gag was observed to accumulate both at the plasma membrane and in an apparently internal compartment that bears markers characteristic of late endosomes or multivesicular bodies. Significantly, the internal Gag rapidly translocated to the junction between the infected macrophages and uninfected T cells following macrophage/T-cell synapse formation. These data indicate that a population of Gag in infected macrophages remains sequestered internally and is presented to uninfected target cells at a virological synapse.


Available from: David E Ott
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    • "Cell-cell spread of HIV-1 is not restricted to dissemination of virus between T cells. Macrophages can also transmit virus by direct cell-cell spread to T cells [12,42]. Macrophages support productive infection by HIV-1 and are also considered to act as long-lived reservoirs that may contribute to viral persistence. "
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    • "In addition, other unknown factors may be required to regulate this targeting (Ono et al., 2004b; Gousset et al., 2008; Mlcochova et al., 2013). "
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    Frontiers in Microbiology 06/2014; 5:312. DOI:10.3389/fmicb.2014.00312 · 3.99 Impact Factor
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    • "movement of the viral RNA in the PM and the progressive accumulation of Gag molecules over time, suggest that after the RNA–Gag complex attaches to the PM, it moves in the PM plane to recruit more Gag molecules. Furthermore, it has been shown that HIV-1 Gag translocate from internal compartments towards virological synapses, which are the contact sites that allow the virus to be transferred, between infected macrophages and uninfected T cells (Gousset et al., 2008). Therefore, it is possible that the Gag anchored to the PM can also traffic to these virological synapses. "
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