Association between increases in calcium response and sensitivity to protein synthesis inhibition by anti-B4–bR in Namalwa (•) and Daudi cells (○). (A) Increase in calcium response was expressed as the peak values (achieved at 2 to 3 minutes after IT addition) of percent increase in fluorescence over the level induced by unconjugated anti-B4 MoAb. Numbers in parentheses indicate the peak values of percentage of responding cells to anti-B4–bR over the effect of anti-B4. (B) Inhibition of protein synthesis was monitored by incorporation of 3H-leucine. Cells were incubated for 18 hours at 37°C with IT, washed twice and pulsed for 4 hours at 37°C with 1 μCi of 3H-leucine. Results are expressed as the mean cpm × 10−3 of two separate experiments, each performed in triplicate. The standard error of the mean (SEM) of each determination did not exceed 10%.
