Biophysical Society Thematic Meeting | Ascona, Switzerland

Liposomes, Exosomes, and Virosomes: From Modeling Complex Membrane Processes to Medical Diagnostics and Drug Delivery

Poster Abstracts

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.

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