HIV-1 virion accumulation and ATP-induced release in human

primary monocyte-derived macrophages

AIDS Immunopathogenesis UnitVita-Salute San Raffaele University, Milan, Italy

Francesca GrazianoPhD Student

Poster n°WEPDA0103

Macrophage

Virion synthesis & accumulation

CD4+ T cell

Cell Death

What is the nature of HIV-containing vacuoles?

What else is contained in addition to HIV virions?

ATPP2X7

Receptor

Permeabilized

plasma membrane

Pyroptotic/NecroticPathway

Exosome Pathway

Microvesicles Pathway

Autophagic Pathway

HIV-1

Hypothesis:Are the intracellular HIV-1 virions released by extracellular ATP stimulation, like IL-1b?

IL-1 β ?

The IL-1b Release Pathway. A potential model for HIV-1 infection of Mø?

MODEL (I): Chronically infected promonocytic cell line U1 (2 copies of integrated virus/cell).

N=8

* *** ***oxATP

ATP

HIV-1

1 min. 5 min. 10 min.

Untreated

oxATP

ATP

N=3

**

IL-1b

N=8

uPA prevents virion release from PMA stimulated U1 cells

uPA: urokinase-type Plasminogen Activator

ATP induces a release pathway in stimulated U1 cells

Alternatively Activated M2-MDM

Classically Activated M1-MDM

IL-4IFN-MDM

N=18

MODEL (II)HIV-1 Infection of primary monocyte-derived macrophages (MDM)

N=25MDM

10’ 20’ 30’

M1-MDM M2-MDM

10’ 20’ 30’ 10’ 20’ 30’

Untreated

ATP

ATP induces the release of HIV virions from HIV-1 infected MDM

p24

UN 1 mM ATP

FSC

MDMUN 1 mM ATP

M2-MDM

ATP reduces the intracellular amount

of HIV-1 virions16,7 9,63 20,2 6,78

1 representative of 7

Conclusions

HIV-1 virions accumulate in intracellular vacuoles in differentiated U1 cells and primary MDM.

ATP promotes the release of IL-1b and HIV-1 virions in both cell types.

These results suggest that HIV-1 exploits the microvesicle pathway to be released from infected macrophages.

Acknowledgements

AIDS Immunopathogenesis Unit

Guido Poli

Massimo Alfano

Elisa Vicenzi

INSPE Division of Neuroscience

Roberto Furlan

Livia Garzetti

Humanitas Clinical and Research Center

Massimo Locati

Poster N° WEPDA0103