Differences in cytochalasin D-induced surface alterations between chronic lymphocytic leukaemic and normal lymphocytes.

Cytochalasin D (CD) causes an unusual surface alteration in normal lymphocytes consisting of the formation of focal irregular club-shaped cell processes. Lymphocytes from chronic lymphocytic leukaemic cases did not show this change on exposure to CD. There was either no surface change or, in some cases, clear double-membrane lined vesicles were formed and appeared to be discharged from the cell. This difference in response may be related to the changes in cell membranes known to occur in malignant transformation.