Cytochalasins distinguish by their action resting human T lymphocytes from activated T-cell blasts.
In the majority of resting human peripheral T lymphocytes obtained from separate individuals cytochalasin B (CB) and D (CD) cause a disappearance of microvilli and induce a rapid formation of prominent sac and bleb-like projections with a length of 1-10 microns randomly distributed over the cell surface. During mitogen stimulation the cells lose the tendency to develop such projections when subsequently exposed to CB and CD. By contrast, in activated T lymphocytes the cytochalasins provoke an asymmetric localization of microvilli including cell surface antigens and actin to a prominent protuberance often separated from the cell body by a constriction. This protuberance is distinct from conventional spontaneous uropods formed by conA-stimulated lymphocytes in relation to contact with other cells and with non-cellular surfaces. The cytochalasins therefore in their action distinguish resting small lymphocytes from activated T-cell blasts.
D000199:Actins / Q000032:analysis; D000954:Antigens, Surface / Q000032:analysis; D002462:Cell Membrane / Q000187:drug effects / Q000648:ultrastructure; D003208:Concanavalin A / Q000494:pharmacology; D003571:Cytochalasin B / Q000494:pharmacology*; D015638:Cytochalasin D; D003572:Cytochalasins / Q000494:pharmacology*; D006801:Humans; D008213:Lymphocyte Activation; D008871:Microvilli / Q000187:drug effects; D013601:T-Lymphocytes / Q000187:drug effects* / Q000276:immunology / Q000648:ultrastructure
D000199:Actins; D000954:Antigens, Surface; D003572:Cytochalasins; D003208:Concanavalin A; D015638:Cytochalasin D; D003571:Cytochalasin B