Macrophage-derived HIV-1 carries bioactive TGF-beta

Area of Science:

• Virology
• Immunology
• Cell Biology

Background:

• Human Immunodeficiency Virus type 1 (HIV-1) infects T cells and macrophages, which are primary producers of the virus.
• Released HIV-1 virions incorporate host cell-derived proteins, but their functions remain largely uncharacterized.
• Cell-specific markers like CD36 and CD27 can distinguish virions originating from different cell types.

Purpose of the Study:

• To investigate the presence and function of cell-encoded proteins on HIV-1 virions.
• To identify specific proteins on macrophage- and T-cell-derived HIV-1 virions.
• To explore the role of these proteins in viral pathogenesis.

Main Methods:

• Flow virometry was employed to analyze HIV-1 virions from HIV-infected individuals.
• Cell-specific markers CD36 (macrophage) and CD27 (T-cell) were used to identify virion origin.
• Multiple assays were utilized to detect and confirm the binding of transforming growth factor beta (TGF-β) to virion-associated proteins.

Main Results:

• HIV-1 virions derived from macrophages (CD36+) were found to carry transforming growth factor beta (TGF-β).
• TGF-β was shown to bind to CD36 on the virions via thrombospondin one (TSP-1).
• The TGF-β molecules on CD36+ virions were biologically active and present in significant amounts (28.2%), unlike on CD27+ virions (1%).

Conclusions:

• Macrophage-derived HIV-1 virions can carry and deliver biologically active TGF-β.
• This mechanism may play a significant role in HIV pathogenesis by modulating target cells.
• Further research is warranted to understand the implications of TGF-β delivery by HIV-1.