Figure 4. SIL inhibits stimulus-induced expansion of CD4+ T cells expressing the HIV co-receptors CXCR4 and CCR5 (panel A) but does not affect the relative frequency of CD4+ T cells expressing co-receptors (panel B).

PBMCs were stimulated with PHA for 3 days prior to exposure to IL-2 and the indicated concentrations of SIL. Twenty-four hours later, cells were stained for CD4, CXCR4, and CCR5 and analyzed by flow cytometry. A, Y-axis represents the concentration of the indicated cell type. The cell concentration is expressed per µl of cell suspension and was determined using counting beads. Panel B shows the percentage of total CD4+ T cells that express one, both, or neither co-receptor.