HIV-1 virion accumulation and ATP-induced release in human primary monocyte-derived macrophages Francesca Graziano PhD Student Poster n°WEPDA0103 AIDS Immunopathogenesis Unit Vita-Salute San Raffaele University, Milan, Italy
CD4+ T cell Cell Death What is the nature of HIV-containing vacuoles? What else is contained in addition to HIV virions? Macrophage Virion synthesis & accumulation
ATP Exosome Pathway The IL-1b Release Pathway. A potential model for HIV-1 infection of Mø? P2X7 Receptor IL-1 β ? Microvesicles Pathway HIV-1 Pyroptotic/Necrotic Pathway AutophagicPathway Hypothesis: Are the intracellular HIV-1 virions released by extracellular ATP stimulation, like IL-1b? Permeabilized plasma membrane
uPA prevents virion release from PMA stimulated U1 cells MODEL (I): Chronically infected promonocytic cell line U1 (2 copies of integrated virus/cell). oxATP ATP *** *** * N=8 uPA: urokinase-type Plasminogen Activator ATP induces a release pathway in stimulated U1 cells HIV-1 IL-1b N=8 * * Untreated oxATP ATP N=3 1 min. 5 min. 10 min.
MODEL (II) HIV-1 Infection of primary monocyte-derived macrophages (MDM) MDM IL-4 IFN- Alternatively Activated M2-MDM Classically Activated M1-MDM ATP induces the release of HIV virionsfrom HIV-1 infected MDM M2-MDM MDM UN UN 1 mM ATP 1 mM ATP Untreated ATP FSC p24 10’ 20’ 30’ 10’ 20’ 30’ N=18 M1-MDM N=25 M2-MDM ATP reduces the intracellular amount of HIV-1 virions 16,7 9,63 6,78 20,2 1 representative of 7 MDM 10’ 20’ 30’
Conclusions HIV-1 virions accumulate in intracellular vacuoles in differentiated U1 cells and primary MDM. ATP promotes the release of IL-1band HIV-1virionsin both cell types. These results suggest that HIV-1 exploits the microvesicle pathway to be released from infected macrophages.
Acknowledgements AIDS Immunopathogenesis Unit INSPE Division of Neuroscience Guido Poli Roberto Furlan Massimo Alfano LiviaGarzetti Elisa Vicenzi Humanitas Clinical and Research Center Massimo Locati Poster N° WEPDA0103