Proposed mechanisms of HIV-associated lymphocyte apoptosis
| Effector . | Proposed mechanism . | Target cell . |
|---|---|---|
| HIV Tat | Enhanced Fas sensitivity | Infected + |
| Enhanced Fas ligand production | uninfected cells | |
| HIV Nef | Activation | Infected + |
| Enhanced FasL production | uninfected cells | |
| ? Binding to unidentified receptor | ||
| HIV vpr | Cell cycle arrest | Infected + |
| Direct effect on mitochondrial permeability | uninfected cells | |
| HIV protease | Cleavage of host structural proteins | Infected cells |
| Activation-induced cell death | HIV-associated activation | Uninfected cells |
| Increased TRAIL/APO-2L, FasL, or both | ||
| gp 120/160 | Inappropriate activation after CD4 ligation | Uninfected cells |
| Enhanced Fas susceptibility/FasL production | ||
| ? Nonapoptotic death by CXCR4 | ||
| Autologous cell–mediated killing | Enhanced production of cytotoxic ligands by HIV-infected cells | Uninfected cells |
| Effector . | Proposed mechanism . | Target cell . |
|---|---|---|
| HIV Tat | Enhanced Fas sensitivity | Infected + |
| Enhanced Fas ligand production | uninfected cells | |
| HIV Nef | Activation | Infected + |
| Enhanced FasL production | uninfected cells | |
| ? Binding to unidentified receptor | ||
| HIV vpr | Cell cycle arrest | Infected + |
| Direct effect on mitochondrial permeability | uninfected cells | |
| HIV protease | Cleavage of host structural proteins | Infected cells |
| Activation-induced cell death | HIV-associated activation | Uninfected cells |
| Increased TRAIL/APO-2L, FasL, or both | ||
| gp 120/160 | Inappropriate activation after CD4 ligation | Uninfected cells |
| Enhanced Fas susceptibility/FasL production | ||
| ? Nonapoptotic death by CXCR4 | ||
| Autologous cell–mediated killing | Enhanced production of cytotoxic ligands by HIV-infected cells | Uninfected cells |