Single-molecule 3D imaging of HIV cellular entry by liquid-phase electron tomography

Journal Article · Thu Feb 03 23:00:00 EST 2022

DOI:https://doi.org/10.21203/rs.3.rs-1298112/v1· OSTI ID:1896472

Kong, Lingli ^[1]; Liu, Jianfang ^[1]; Zhang, Meng ^[1]; Lu, Zhuoyang ^[2]; Ren, Amy ^[3]; Liu, Jiankang ^[4]; Li, Jinping ^[5]; Ren, Gang ^[1]

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1. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
2. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Xi'an Jiaotong Univ., Shaanxi (China)
3. Univ. of California, Santa Barbara, CA (United States)
4. Xi'an Jiaotong Univ., Shaanxi (China)
5. Mayo Clinic, Jacksonville, FL (United States)

Enveloped viruses, including human immunodeficiency virus (HIV) and SARS-CoV-2, target cells through membrane fusion process. The detailed understanding of the process is sought after for vaccine development but remains elusive due to current technique limitations for direct three-dimensional (3D) imaging of an individual virus during its viral entry. Recently, we developed a simple specimen preparation method for real-time imaging of metal dynamic liquid-vaper interface at nanometer resolution by transmission electron microscopy (TEM). Here, we extended this method to study biology sample through snapshot 3D structure of a single HIV (pseudo-typed with the envelope glycoprotein of vesicular stomatitis virus, VSV-G) at its intermediate stage of viral entry to HeLa cells in a liquid-phase environment. By individual-particle electron tomography (IPET), we found the viral surface release excess lipids with unbound viral spike proteins forming ~50-nm nanoparticles instead of merging cell membrane. Moreover, the spherical-shape shell formed by matrix proteins underneath the viral envelope does not disassemble into a cone shape right after fusion. Further, the snapshot 3D imaging of a single virus provides us a direct structure-based understanding of the viral entry mechanism, which can be used to examine other viruses to support the development of vaccines combatting the current ongoing pandemic.

• Research Organization: Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES); National Institutes of Health (NIH)
• DOE Contract Number: AC02-05CH11231
• OSTI ID: 1896472
• Country of Publication: United States
• Language: English