Human Immunodeficiency Virus 1 (HIV-1) has evolved sophisticated strategies to limit the presentation of viral epitopes to the immune system. This is evidenced by the ability of the virus to minimize the number of exposed Envelope proteins on the virus surface at the expense of virus infectivity. How HIV-1 regulates the incorporation of viral Envelope proteins into assembling particles is still very unclear. We hypothesize that specific motifs found within the HIV-1 Envelope cytoplasmic domain as well as host cell membrane lipids regulate the acquisition of Env into assembling virus particles. In our first aim of this proposal, we will quantify the single molecule nanoscale dynamics of HIV-1 Envelope and mutants of the cytoplasmic domain on the surface of producing cells. In our second aim, we will measure the three-dimensional (3D) structural organization and angular distribution of HIV-1 Envelope on the surface of budding virus particles. For both aims, we propose to identify key viral and host cell membrane determinants responsible for the spatiotemporal association of HIV-1 Envelope with nascent virus assembly sites.
Both aims will utilize the tens of nanometer resolution and molecular specificity of three-dimensional superresolution microscopy to illuminate the dynamics and organization of HIV-1 Envelope. Our quantitative approach will provide the necessary foundational knowledge for constructing accurate models of HIV-1 Envelope acquisition into virus assembly sites. We believe that these models will aid in the future development of novel strategies aiming to inhibit accessibility of HIV-1 Envelope to virus assembly sites.
Human Immunodeficiency Virus 1 (HIV-1) assembly requires exquisite coordination between the cellular targeting (Envelope) and structural (Gag) proteins to create an infectious particle. As such, a fundamental understanding of the mechanisms governing the assembly of HIV-1 particles is imperative to devise new therapeutic strategies to combat viral infection. Our goal is to develop new methodology to fill a resolution gap, the tens of nanometer scale, in our understanding of HIV-1 assembly and identify key viral and host cell membrane moieties responsible for promoting this process.
| Buttler, Carmen A; Pezeshkian, Nairi; Fernandez, Melissa V et al. (2018) Single molecule fate of HIV-1 envelope reveals late-stage viral lattice incorporation. Nat Commun 9:1861 |
| Kopek, Benjamin G; Paez-Segala, Maria G; Shtengel, Gleb et al. (2017) Diverse protocols for correlative super-resolution fluorescence imaging and electron microscopy of chemically fixed samples. Nat Protoc 12:916-946 |
