Cell killing by ultraviolet-inactivated human immunodeficiency virus

Area of Science:

• Virology
• Immunology
• Cell Biology

Background:

• Human immunodeficiency virus (HIV) infection leads to T-4 lymphocyte depletion.
• The precise mechanisms of HIV-induced cytopathology are not fully understood.

Purpose of the Study:

• To investigate the component of HIV responsible for cell killing and cytopathology in human T-4 lymphocytes.
• To determine if soluble factors released by infected cells contribute to observed cell death.

Main Methods:

• Exposure of RH9 human T-4 lymphocyte cell line to HIV-containing culture supernatants.
• Treatment with ultraviolet-irradiated HIV to assess infectivity and cytopathic effects.
• Analysis of cell-free supernatants from persistently infected cells for cytotoxic activity.
• Characterization of the cell-killing fraction's hydrodynamic properties.

Main Results:

• HIV induced extensive cell killing and cytopathology in RH9 cells within 24 hours.
• Ultraviolet-irradiated HIV, incapable of proviral DNA formation, still caused indistinguishable cytopathic effects.
• Persistently infected cells did not release soluble cytotoxic factors.
• The cell-killing fraction exhibited retroviral hydrodynamic properties.

Conclusions:

• A virion component, rather than soluble factors, is likely responsible for HIV-induced cell killing.
• The cytopathic effects of HIV can occur independently of viral DNA replication.