Human immunodeficiency virus pseudotypes with expanded cellular and species tropism

Area of Science:

• Virology
• Molecular Biology
• Immunology

Background:

• Viral tropism can be expanded by forming phenotypically mixed virus particles (pseudotypes).
• This occurs when cells are infected with multiple viruses simultaneously.
• Understanding viral tropism is crucial for studying viral pathogenesis and developing therapies.

Purpose of the Study:

• To investigate the production and characteristics of human immunodeficiency virus (HIV) pseudotypes generated through dual infection.
• To determine the cellular tropism and replication efficiency of these HIV pseudotypes in various cell types.
• To assess the potential utility of HIV pseudotypes for studying HIV molecular biology.

Main Methods:

• Dual infection of cells with HIV and a murine amphotropic retrovirus.
• Production and characterization of HIV pseudotypes.
• Assessing viral replication via HIV antigen detection and co-cultivation assays.
• In situ cytohybridization to confirm infection.
• Superinfection exclusion experiments.

Main Results:

• Dual infection yielded HIV pseudotypes with the amphotropic retrovirus host range, infecting CD4- human and mouse cells.
• Human foreskin fibroblasts were the most efficient host cells, with documented infection of all cells.
• HIV pseudotype infection led to HIV-specific protein expression similar to that in CD4+ cells.
• Superinfection exclusion was observed in fibroblasts pre-infected with amphotropic retrovirus.
• Substantial HIV production occurred in various other cell lines, including mouse cells, despite lower efficiency.

Conclusions:

• HIV pseudotypes generated via dual infection exhibit expanded cellular tropism.
• These pseudotypes can infect a broader range of cells, including non-human cells.
• The findings suggest HIV pseudotypes are valuable tools for studying HIV molecular biology across diverse cell types.