Table 1.
Study subjects and CTL responses to conserved and variable epitopes
| Primary infectiona | Chronic infectiona | |||
|---|---|---|---|---|
| Subjects | ||||
| Number | 34 | 16 | ||
| Median (range) days post onset of acute symptoms b | 27 (3 – 91) | 357 (109 – 1182) | ||
| Median (range) Log10 viral load (copies/ml) | 4.98 (2.88 –6.92) | 4.36 (<1.7 – 5.57) | ||
| Median (range) CD4+ T cell count (cells/μl) | 684 (241 – 1090) | 574 (130 – 1325) | ||
| Epitopes c | Conserved | Variable | Conserved | Variable |
| Fraction of subjects with CTL responses | 0.5 | 1 | 0.5 | 1 |
| Median (range) number of epitopes recognized | 1 (0–3) | 2 (1–8) | 1 (0–2) | 3 (1–9) |
| Probability of recognition | 0.145 | 0.173 | 0.143 | 0.239 |
Primary and chronic infection were defined in this study as occurring before or after 91 days of onset of acute symptoms of viral infection, respectively. These symptoms usually arise within about 2 weeks post exposure to HIV in this cohort (J.I. Mullins, data not shown).
PBMC specimens from these time points were derived and examined for CTL responses.
Conserved epitopes were defined as belonging to the upper quartile of the tested epitopes in terms of database frequency (conserved in greater than 78.68% of the sequences of HIV-1 subtype B in Las Alamos HIV Sequence Database of year 2005 [29]), while epitopes in the lower three quartiles were considered to be variable epitopes.