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Liposomes, Exosomes, and Virosomes: From Modeling Complex
Membrane Processes to Medical Diagnostics and Drug Delivery
Poster Abstracts
80
20-POS
Board 10
Imaging the Packing State and Lateral Organization of the HIV-1 Membrane Lipids by
Two-Photon and Atomic Force Microscopy
Pablo Carravilla
1,2
, Antonio Cruz
3
, Maier Lorizate
1,2,4
, Hans-Georg Kräusslich
4
, Jesús Pérez-
Gil
3
, José Luis Nieva
1,2
, José Requejo-Isidro
2
, Nerea Huarte
1,2
.
1
Universidad del País Vasco/Euskal Herriko Unibertsitatea (UPV/EHU), Bilbao, Bizkaia, Spain,
2
Unidad de Biofísica (CSIC, UPV/EHU), Leioa, Bizkaia, Spain,
3
Universidad Complutense,
Madrid, Spain,
4
Universität Heidelberg, Heidelberg, Germany.
The chemical composition of the human immunodeficiency virus type 1 (HIV-1) envelope is
critical for fusion and entry into cells suggesting that preservation of a functional lipid bilayer
organization may be required for efficient infection. The HIV-1 acquires its envelope from host
cell plasma membranes at sites enriched in raft-type lipids. Furthermore, infectious particles
display aminophospholipids in their surface, indicative of dissipation of the inter-leaflet lipid
asymmetry metabolically generated at plasma membranes. Here, using membrane lipids
extracted from infectious HIV-1 particles, we have correlated information on lipid-packing
obtained using two-photon Laurdan fluorescence imaging and lipid organization on the
nanoscale using atomic force microscopy. We have established the roles played by the different
HIV lipid components and obtained unprecedented insights into its phase state that are critical to
the complete description of the viral entry mechanism.