Alpha interferon accelerates lateral diffusion of Daudi cell surface differentiation antigens: measurement by...

Lateral diffusion coefficients (D) of two surface differentiation antigens (sIgM and Bp35) were determined on interferon-sensitive (-IFs) or resistant (-IFr) Daudi cells by fluorescence photobleaching, using monospecific FITC-anti-IgM or PE-anti-Leu 16 probes. For untreated Daudi -IFs, mean (D) were 5.8 and 5.3 (x10(-10) cm2/sec). These increased, to 11 and 7.9 x 10(-10) cm2/sec (p less than 0.001) within 30 min after binding of recombinant IFN-a (80 to 800 U/10(6) cells), but decreased by up to 4-fold after Con A Mean (D) of identical surface antigens on Daudi-IFr were 8.2 and 9.4 x 10(-10) cm2/sec; and were not altered by IFN-a. Mean (D) of a lipid analog was up to 40-fold higher than for surface proteins and statistically identical in Daudi-IFs and Daudi-IFr. Rapid acceleration by IFN-a of surface protein lateral diffusion in Daudi-IFs obviously could facilitate anti-proliferative signal transduction; by contrast, a baseline increase of (D) in Daudi-IFr was evidently associated with their refractory state.