Atomic Force Microscopy Detect Transient Frictional Contrasts in Apoptotic Cells Induced by Deprivation of Interleukin-3.

The morphological changes of murine hematopoietic 32D Cl3-A cell line, in which apoptosis was induced by deprivation of interleukin-3 (IL-3) from the culture medium, were studied through air operating atomic force microscopy (AFM). The subtraction of IL-3 determines the appearing of blebs on plasma membrane and cell fragmentation in several residual bodies. Areas of strong contrast in the friction images, which are nearly absent in control and necrotic cells, were detected with percentage that peaks at 6 hours of IL-3 deprivation. These are the first results revealing that transient modification of the plasma membrane accompanies the first steps of apoptosis pathway.