HIV-1 Accessory Proteins Impart a Modest Interferon Response and Upregulate Cell Cycle-Related Genes in Macrophages

Area of Science:

• Immunology
• Virology
• Molecular Biology

Background:

• HIV-1 infection in myeloid cells triggers an interferon (IFN) response.
• Understanding HIV-1's manipulation of the IFN response is crucial for developing therapeutics to restore immune function in individuals living with HIV.
• HIV-1 accessory genes are vital for viral fitness, altering host pathways to evade immune surveillance.

Purpose of the Study:

• To elucidate the specific roles of individual HIV-1 accessory genes in upregulating IFN-regulated and cell cycle-related genes.
• To investigate how these viral proteins influence host cell transcriptional patterns.

Main Methods:

• Utilized RNA sequencing to analyze transcriptomic changes in HIV-1 infected cells.
• Compared gene expression profiles of cells infected with HIV-1 to those stimulated with interferons (IFNs).
• Assessed the impact of individual viral accessory genes (Vif, Vpr, Vpu, Nef) on host gene transcription.

Main Results:

• HIV-1 Vif protein induces genes involved in mitotic processes, which are suppressed by type-I and -II IFN stimulation.
• HIV-1 Vpr protein upregulates cell cycle genes and is responsible for an attenuated IFN response, resembling a type-III IFN signature.
• HIV-1 Vpu and Nef proteins regulate smaller gene sets associated with cytokine and chemokine pathways.

Conclusions:

• HIV-1 accessory proteins differentially manipulate host cell transcription, particularly affecting cell cycle and immune response genes.
• Vif and Vpr play significant roles in altering cell cycle gene expression and modulating the IFN response during HIV-1 infection.
• This study enhances our understanding of how HIV-1 accessory proteins subvert host cellular processes at the transcriptional level.