Cytokine expression by ND-R4 cells.

ND-R4 cells expressed single cytokines. Expression of IFN-γ, IL-2, and IL-4 was examined by flow cytometric analysis in ND-R4, which was stimulated with autologous BLCLs for 5 hours in the presence of BFA. A gate was placed on CD4⁺ events. Panels E-H are for cells stimulated as in panels A-D, but stained with respective control isotype antibodies. Note that the CD4^high cells expressed IL-4, while CD4^dim cells were positive for IFN-γ only. A representative of 2 independent experiments is shown.