Lv2, a novel postentry restriction, is mediated by both capsid and envelope

Area of Science:

• Virology
• Molecular Biology
• Immunology

Background:

• Lentivirus replication restrictions offer insights into viral life cycles and therapeutic targets.
• Previous work identified a post-reverse transcription, pre-nuclear entry restriction in human immunodeficiency virus type 2 (HIV-2).
• This restriction can be bypassed using a vesicular stomatitis virus glycoprotein G (VSV-G) envelope.

Purpose of the Study:

• To investigate the molecular basis of a lentiviral restriction.
• To identify the viral components responsible for restricting lentivirus replication.
• To determine if this restriction is a novel mechanism and its implications for HIV-1 infection.

Main Methods:

• Analysis of molecular clones of restricted (MCR) and unrestricted (MCN) viruses.
• Sequence analysis and gene swapping to map viral determinants.
• Site-directed mutagenesis and pseudotype experiments to confirm the role of specific viral proteins.

Main Results:

• The restriction was mapped to the gag and env genes.
• A single amino acid at position 207 in the capsid (CA) protein was identified as responsible for the gag restriction.
• The restriction mechanism was found to be distinct from known restrictions like Fv1/Ref1/Lv1.
• The findings were relevant for human immunodeficiency virus type 1 (HIV-1) infection.

Conclusions:

• A novel lentiviral restriction, designated Lv2, has been identified.
• The HIV envelope and capsid play a crucial role in ensuring proper viral delivery to cellular compartments for efficient replication.
• This discovery provides new avenues for understanding lentiviral pathogenesis and developing therapeutic strategies.