HIV1 Defying Host Cell’s Weapons
HIV-1 has developed a strategy for survival within infected white blood cells by preventing highly acidic and proteolytic transformation of endocytic compartment, as is the usual weapon against such intrudors. It does so by blocking a proton pump of that compartment, and thus keeping lysosomes away, that would perform the necessary acidification. As such it can stay infectious for indeterminate periods of time in places, where it actually ought to be destroyed efficiently.
Cell Host and Microbe, Volume 2, Issue 2, 16 August 2007, Pages 85-95
HIV-1 Buds and Accumulates in “Nonacidic” Endosomes of Macrophages
Mabel Jouve1, Nathalie Sol-Foulon2, Sarah Watson1, Olivier Schwartz2 and Philippe Benaroch1, ,
1Institut Curie, INSERM U653, 26 rue d’Ulm 75248 Paris Cedex 05, France
2CNRS URA1930, Institut Pasteur, 25-28 rue Dr Roux 75724 Paris Cedex 15, France
Received 27 February 2007; revised 11 May 2007; accepted 29 June 2007. Published: August 15, 2007. Available online 15 August 2007.
Macrophages represent viral reservoirs in HIV-1-infected patients and accumulate viral particles within an endosomal compartment where they remain infectious for long periods of time. To determine how HIV-1 survives in endocytic compartments that become highly acidic and proteolytic and to study the nature of these virus-containing compartments, we carried out an ultrastructural study on HIV-1-infected primary macrophages. The endosomal compartments contain newly formed virions rather than internalized ones. In contrast to endocytic compartments free of viral proteins within the same infected cells, the virus containing compartments do not acidify. The lack of acidification is associated with an inability to recruit the proton pump vacuolar ATPase into the viral assembly compartment. This may prevent its fusion with lysosomes, since acidification is required for the maturation of endosomes. Thus, HIV-1 has developed a strategy for survival within infected macrophages involving prevention of acidification within a devoted endocytic virus assembly compartment.
Author Keywords: MICROBIO; CELLBIO