Figure 4.

Double immunofluorescent labeling of the cultured CD4⁺ T-cell lines. In a) the majority of cultured cells express both CD3 and CD4 antigens (arrow). Heterogeneity was observed in CD4 expression. An example of a CD3⁺ cell CD4⁻ T cell is shown (arrowhead). b) Shows the presence of a small population of CD8⁺ cells (green) c) Co-expression of CD45R0 on the majority of CD4⁺ cells can be observed. An example of a CD4⁺ CD45RO⁻ cell is arrowed. d) Only the occasional cell was CD56⁺ (arrowhead) confirming the presence of only a small number (<1%) of natural killer cells in the cultured cells.