Fig. 2.
Regulation of CD127 expression in memory CD8 lymphocytes taken from viraemic and highly active anti-retroviral therapy (HAART)-treated HIV-infected patients. Peripheral blood mononucear cells (PBMC), prepared as above, were cultured in the absence or presence of interleukin (IL)-7 (10 ng/ml). IL-7 was kindly provided by Cytheris SA (Vanves, France). Cultures (2 × 105 cells/200 microlitre) were performed in 96-well U-bottomed microtitre plates. The medium consisted of RPMI-1640 supplemented with 0·5% human AB serum, 2 mM glutamine, 10 mM HEPES and 50 mM 2-mercaptoethanol. On the days indicated the cells were stained and analysed as described in the legend to Fig. 1. Data were expressed as median [mean fluorescence intensity (MFI)] of all cells in each CD8 lymphocyte subset. For the sake of clarity the figure does not include the interquartile ranges. Statistical analyses were performed by the Wilcoxon matched-pairs signed-ranks test. (a) CD127 down-regulation in the presence of IL-7 was monitored on day 3 and on day 6 was found to be significant when compared to CD127 expression on day 0, and this for all experimental conditions used (P< 0·05). Dotted lines represent the level of CD127 expression on day 0. (b) CD127 over-expression was measured on day 3 in the absence of IL-7. The P-values obtained between day 3 and day 0 are indicated. IL-7 plasma levels were measured in each group by enzyme-linked immunoassay (Quantikine HS kit, RD System, Paris, France): viraemic group [16·2 (13·6–17·2) pg/ml], HAART group [11·0 (8.9–12.8) pg/ml] and healthy donors [1·4 (0·9–2·1) pg/ml]. *P < 0·05 when compared to day 0.