|  | Cells derived form |  |
---|
 | HIV+ | Control | Aged | Control |
---|
In TNF-α studies |  |  |  |  |
% CD28- of the | 68.3 | 36.3 | 64.2 | 27.1 |
total CD8+ cells | Â | Â | Â | Â |
% CD28- | 55.2 | 26.8 | 68.0 | 29.5 |
producing TNF-α |  |  |  |  |
% Total TNF-α± | 79.5 | 20.5 | 84.6 | 15.4 |
In IFN-γ studies |  |  |  |  |
% CD28- of the total | 70.0 | 30.7 | 61.3 | 28.0 |
CD8+ cells | Â | Â | Â | Â |
% CD28- producing | 59.8 | 21.2 | 62.3 | 35.1 |
IFN-γ |  |  |  |  |
% Total IFN-γ ± | 86.7 | 13.3 | 79.6 | 20.4 |
- *Analysis of CD8+ T cells from CD28+ and CD28- subsets in terms of cytokine production was performed by flow cytometry as described in Methods. Twenty HIV+ and aged donors and fifteen control donors were used in the IFN-γ studies; twenty-two and nineteen were used respectively in the TNF-α studies. ± The percent total of TNF-α or IFN-γ refers to the percentage of CD28- cells producing cytokine compared to the total produced by the controls and HIV+ (or aged) CD28- T cells. For example, in the TNF-α studies, 8% of the control CD28- cells produce cytokine (27.1 × 29.5), whereas in the aged state, CD28- cells producing TNF-α is 43.7% (64.2 × 68.0). Thus the TNF-α produced by aged CD28- CD84 T cells is 84.6% compared to 15.4% for controls.