Alpha interferon accelerates lateral diffusion of Daudi cell surface differentiation antigens: measurement by fluorescence redistribution after photobleaching.
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.
Balint
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Department of Pathology, F. Edward Hebert Medical School, USUHS, Bethesda, Maryland 20814.
Aszalos
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A
Grimley
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PM
D018951:Antigens, CD20; D000944:Antigens, Differentiation, B-Lymphocyte / Q000502:physiology*; D004058:Diffusion; D004351:Drug Resistance; D005434:Flow Cytometry; D006801:Humans; D007370:Interferon Type I / Q000494:pharmacology*; D008560:Membrane Fluidity / Q000187:drug effects*; D008856:Microscopy, Fluorescence; D011947:Receptors, Antigen, B-Cell / Q000502:physiology*; D011956:Receptors, Cell Surface / Q000502:physiology; D014407:Tumor Cells, Cultured
D018951:Antigens, CD20; D000944:Antigens, Differentiation, B-Lymphocyte; D007370:Interferon Type I; D011947:Receptors, Antigen, B-Cell; D011956:Receptors, Cell Surface