HIV-1 N-myristoylation-dependent hijacking of late endosomes/lysosomes to drive Gag assembly in macrophages

Macrophages represent an important viral reservoir in HIV-1-infected individuals. Different from T cells, HIV-1 assembly in macrophages occurs at intracellular compartments termed virus-containing compartments (VCCs). Our previous research in HeLa cells - in which assembly resembles that found in infected T cells - suggested that late endosomes/lysosomes (LELs) play a role in HIV-1 trafficking towards its assembly sites. However, the role of LELs during assembly at VCCs is not fully understood. Herein, we used the HIV-1-inducible cell line THP-1 GagZip as a model to study HIV-1 Gag intracellular trafficking and assembly in macrophages. We demonstrated LEL involvement at VCCs using various microscopy techniques and biochemical approaches. Live-cell imaging revealed that HIV-1 repositions LELs towards the plasma membrane and modulates their motility. We showed that Arl8b-mediated LEL repositioning is not responsible for Gag trafficking to VCCs. Additionally, the inhibition of myristoylation by PCLX-001 decreased the presence of Gag on endosomes and inhibited VCC formation in both the THP-1 cell line and primary macrophages. In conclusion, we present evidence supporting the idea that HIV-1 manipulates the LEL trajectory to guide Gag to VCCs in an N-myristoylation-dependent manner.