FIG. 6.

CD3 cross-linking induces Ca²⁺ flux in P116 T cells. Jurkat and P116 T cells were loaded with Indo-1-AM. Baseline fluorescence ratio (405 nm to 495 nm) was measured for 1 min prior to the administration of indicated stimulus, and readings of the fluorescence ratio were acquired for an additional 5 min. (A) Change in fluorescence ratio as a function of time. Concentrations refer to purified UCHT1 MAb. The y-axis scale, reflecting changes in fluorescence ratio, runs from 0 to 160 for Jurkat cells and 0 to 100 for P116 cells. (B) Plot of maximum mean channel response observed during a 6-min run versus anti-CD3 MAb concentration. Solid bars, P116 cells; open bars, parental Jurkat cells. “n.d”, data points that were not determined.