Related Experiment Videos
Myosin-actin interaction plays an important role in human immunodeficiency virus type 1 release from host cells
1Division of Morphology, Jikei University School of Medicine, Tokyo, Japan.
Abstract:
We examined the potential role of myosin and actin in the release of human immunodeficiency virus type 1 (HIV-1) from infected cells. Wortmannin (100 nM to 5 microM), an effective inhibitor of myosin light chain kinase, blocked the release of HIV-1 from infected T-lymphoblastoid and monocytoid cells in a concentration-dependent manner. Cytochalasin D, a reagent that disrupts the equilibrium between monomeric and polymeric actin, also partially inhibited the release of HIV-1 from the infected cells. At the budding stage, myosin and HIV-1 protein were detected in the same areas on the plasma membrane by using dual-label immunofluorescence microscopy and immunoelectron microscopy. In the presence of 5 microM wortmannin, viral components were observed on the plasma membrane by using immunofluorescence microscopy and electron microscopy, implying that wortmannin did not disturb the transport of viral proteins to the plasma membrane but rather inhibited budding.
Insights
Myosin and actin play a role in human immunodeficiency virus type 1 (HIV-1) release. Inhibiting myosin light chain kinase with wortmannin blocked HIV-1 release, suggesting it inhibits viral budding.
Area of Science:
- Virology
- Cell Biology
- Molecular Biology
Background:
- The release of human immunodeficiency virus type 1 (HIV-1) from infected cells is a critical step in viral replication and pathogenesis.
- The specific cellular mechanisms governing HIV-1 release, particularly the involvement of the host cell cytoskeleton, are not fully elucidated.
Purpose of the Study:
- To investigate the potential involvement of myosin and actin cytoskeletal components in the release of HIV-1 from infected cells.
- To determine the effect of specific inhibitors of myosin and actin on HIV-1 release.
Main Methods:
- Utilized T-lymphoblastoid and monocytoid cells infected with HIV-1.
- Employed wortmannin, an inhibitor of myosin light chain kinase, and cytochalasin D, which affects actin polymerization.
- Visualized viral components and myosin at the plasma membrane using dual-label immunofluorescence microscopy and immunoelectron microscopy.
Main Results:
- Wortmannin inhibited HIV-1 release in a concentration-dependent manner.
- Cytochalasin D partially inhibited HIV-1 release.
- Myosin and HIV-1 proteins were co-localized at the plasma membrane during the budding stage.
- Wortmannin treatment prevented viral budding without affecting viral protein transport to the plasma membrane.
Conclusions:
- Myosin and actin are implicated in the budding and release of HIV-1 from infected cells.
- Inhibition of myosin light chain kinase by wortmannin specifically blocks the budding process, not viral protein transport.
- These findings highlight potential therapeutic targets for inhibiting HIV-1 replication by interfering with host cell machinery.