Correlation of the biologic effects and binding of cytochalasins to human
polymorphonuclear leukocytes
TH Howard, J Casella and S Lin
Treatment of human PMNs with cytochalasins (CE, CD, CB, and H2CB) results
in alteration of cell morphology and inhibition of cell motility.
Morphological changes are similar to those reported for nonamoeboid
fibroblasts--rounding, zeiosis, and arborization. Mean cell velocity of
PMNs, as measured by quantitative analysis of time-lapse videotape
recordings, was reduced to 0.1 micron/min (control, 7.3 +/- 4.2
micron/min). Phagocytosis by PMNs, as measured by phagocytosis of latex
beads, was inhibited by 75%. The relative potency of the cytochalasins for
inducing morphological change or for inhibiting locomotion and phagocytosis
is similar to their relative potencies for affecting non-amoeboid cells: CE
greater than CD greater than CB greater than or equal to H2CB. Quantitative
binding of 3H-CB to purified PMNs under equilibrium conditions reveal two
types of specific CB binding sites: high-affinity sites (KD approximately 3
x 10(-7) M, 3 x 10(6) sites/cell) and low affinity sites (KD approximately
2 x 10(-6) M). The relative affinities of the cytochalasins for the
high-affinity and low-affinity CB binding sites parallel their relative
potencies for inducing biologic effects (i.e. CE greater than CD greater
than CB greater than or equal to H2CB).
Volume 57,
Issue 3,
pp. 399-405,
03/01/1981
Copyright © 1981 by The American Society of Hematology
