Abstract
Examination of annexin V binding, an indicator of early apoptosis, on lymphocytes from HIV+ people immediately after isolation showed that both CD4+ and CD8+ T cells were apoptotic, whereas B cell apoptosis was induced mainly after incubation. CD8+ T cell apoptosis correlated with fewer CD4+ T cells, but not the level of viremia. To determine potential mechanisms for apoptosis, we examined FasL expression, which was dramatically elevated on CD14+ monocytes; however, antibody to FasL did not reproducibly inhibit apoptosis. Rather, CD8+ T cell apoptosis was caused by antigen-presenting cells because removal of monocytes or addition of antibodies to CD80 and CD86 reduced apoptosis. B cell apoptosis also involved costimulatory signals delivered by T cells but not monocytes. A unique CD8(bright)CD28(dim) T cell population died after costimulation by monocytes. Because this population was increased in patients with undetectable viremia, abnormal antigen-presenting cells may contribute to continued CD8+ T cell exhaustion by inducing apoptosis.
Original language | English (US) |
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Pages (from-to) | 302-312 |
Number of pages | 11 |
Journal | Clinical Immunology |
Volume | 90 |
Issue number | 3 |
DOIs | |
State | Published - Jan 1 1999 |
Keywords
- Annexin V
- Apoptosis
- Fas
- Fas-ligand
- HIV
ASJC Scopus subject areas
- Immunology and Allergy
- Immunology