Recent studies have indicated that GM3 (a ganglioside that contains a terminal ?-2,3 linked sialic acid residue) can mediate glycoprotein independent interactions between human immunodeficiency virus 1 (HIV-1) and dendritic cells (DCs) and can, thus, induce an envelope glycoprotein-independent capture of the virus by DCs. Many aspects of this important capture mechanism remain unknown and its systematic investigation is challenged by a lack of appropriate tools to characterize the concentration and spatial distribution of GM3 in the virus membrane and of appropriate virus model systems with clearly defined surface composition. This proposal seeks to overcome these challenges by developing new noble metal nanoparticle-based tools for investigating the role of non-virus encoded surface functionalities in the pathogenesis of HIV-1. We will take advantage of the unique electromagnetic properties of noble metal nanoparticles to quantify the - as yet unknown - surface density of GM3 and its spatial distribution on viruses derived from peripheral blood mononuclear cells (PBMCs). Quantitative information about the GM3 content in HIV-1 particles will form the basis for the implementation of artificial virus nanoparticles (AVNs) that contain a gold core wrapped in a phospholipid bilayer membrane whose lipid composition mimics that of the native virus. As artificial, engineerable nanoparticles, it is possible to tune AVN GM3 surface concentration in a systematic fashion without the risk of including any other host or virus encoded surface functionalities. The AVNs introduced herein combine the advantageous material properties of metal NPs with the programmable functionality of biological membranes, are conveniently generated in large quantities, provide large optical cross-sections in fluorescent and darkfield optical microscopy, and can be localized with high resolution in both electron and optical microscopy. AVNs are, thus, ideal tools to determine the contribution of GM3 in the capture of HIV-1 particles on DCs and will enable us to probe the probe the intricate mechanisms underlying the GM3- dependent HIV-1 invasion of DCs.
The specific aims of this application are:
Aim1 : To define the role of GM3 in interactions of primary HIV-1 isolates with DCs using nanoparticle enabled assays Aim2: To develop artificial virus nanoparticles (AVNs) that mimic GM3-mediated HIV-1 capture Aim3: To elucidate the molecular mechanisms underlying GM3-CD169 mediated binding and uptake of HIV-1 particles within DCs using AVNs.

Public Health Relevance

This proposal develops new nanotechnologies for elucidating the role and mode of action of non-virus encoded surface functionalities in the capture of HIV-1 by dendritic cells. Artificial virus nanoparticles with host-derived surface groups will make it possible to quantify the contribution of these surface functionalities to the efficiency of the dendritic cell-mediated trans infection pathway. The research will pave the way towards novel therapeutics for suppressing the worldwide growth of the HIV-1 pandemic.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
High Priority, Short Term Project Award (R56)
Project #
1R56AI104393-01A1
Application #
8682127
Study Section
Special Emphasis Panel (ZRG1-AARR-E (81))
Program Officer
Sharma, Opendra K
Project Start
2013-07-01
Project End
2014-06-30
Budget Start
2013-07-01
Budget End
2014-06-30
Support Year
1
Fiscal Year
2013
Total Cost
$384,695
Indirect Cost
$149,695
Name
Boston University
Department
Chemistry
Type
Schools of Arts and Sciences
DUNS #
049435266
City
Boston
State
MA
Country
United States
Zip Code
02215
Yu, Xinwei; Feizpour, Amin; Ramirez, Nora-Guadalupe P et al. (2014) Glycosphingolipid-functionalized nanoparticles recapitulate CD169-dependent HIV-1 uptake and trafficking in dendritic cells. Nat Commun 5:4136