Human Immunodeficiency Virus Type 1 Particles Pseudotyped with Envelope Proteins That Fuse at Low pH No Longer Require Nef for Optimal Infectivity

Nathalie Chazal (1) , Gregory Singer (2) , Christopher Aiken (3) , M.-L. Hammarskjold (2) , David Rekosh (2)

1 IRIM - Institut de Recherche en Infectiologie de Montpellier
2 University of Virginia
3 Vanderbilt University School of Medicine [Nashville]

We have investigated the effects of Nef on infectivity in the context of various viral envelope proteins. These experiments were performed with a minimal vector system where Nef is the only accessory protein present. Our results support the hypothesis that the route of entry influences the ability of Nef to enhance human immu-nodeficiency virus (HIV) infectivity. We show that HIV particles pseudotyped with Ebola virus glycoprotein or vesicular stomatitis virus glycoprotein (VSV-G), which fuse at low pH, do not require Nef for optimal infec-tivity. In contrast, Nef significantly enhances the infectivity of virus particles that contain envelope proteins that fuse at neutral pH (CCR5-dependent HIV Env, CXCR4-dependent HIV Env, or amphotropic murine leu-kemia virus Env). In addition, our results demonstrate that virus particles containing mixed CXCR4-dependent HIV and VSV-G envelope proteins show a conditional requirement for Nef for optimal infectivity, depending on which protein is allowed to facilitate entry.

Domaines: Virologie

Nathalie Chazal, Gregory Singer, Christopher Aiken, M.-L. Hammarskjold, David Rekosh. Human Immunodeficiency Virus Type 1 Particles Pseudotyped with Envelope Proteins That Fuse at Low pH No Longer Require Nef for Optimal Infectivity. Journal of Virology, 2001, 75 (8), pp.4014-4018. ⟨10.1128/JVI.75.8.4014-4018.2001⟩. ⟨hal-02147219⟩