FK506 and pertussis toxin distinguish growth-induced locomotor activation from attractant-stimulated locomotion in human blood lymphocytes.
The locomotor capacity of human lymphocytes is cell cycle-related. Many small blood lymphocytes are non-motile but acquire locomotor capacity in G1 on appropriate activation with e.g. anti-CD3 antibody (aCD3) for T cells, or interleukin-4 (IL-4) for B cells. Once this capacity is acquired, the cells can then respond by polarization and locomotor to chemoattractants such as IL-8 or foetal calf serum (FCS). These two stages in the locomotor process were distinguished by the use of two inhibitors, FK506 and pertussis toxin. FK506 caused a dose-dependent inhibition of cell cycle-related induction of locomotor capacity both of anti-CD3-cultured T cells and IL-4-cultured B cells, with an ID50 of less than 1 ng per ml. This was measured in assays both of morphological polarization and of locomotion into collagen gels. FK506 has no effect on chemoattractant-induced polarization. Conversely, pertussis toxin has little inhibitory effect on growth-induced locomotor capacity, but is an effective inhibitor of the immediate polarization response following addition of FCS or IL-8 to lymphocytes either direct from blood or after overnight culture. These results suggest that different signalling pathways are involved in the two stages. Growth-related locomotor activation does not involve a pertussis toxin-sensitive G protein and may be signalled in the same way as other mitogen-induced events which are sensitive to FK506 and cyclosporin. On the other hand, the locomotor response to attractants, on this and earlier evidence, is transduced via a pertussis toxin-sensitive G protein. However, after prolonged (24-48 hr) culture in the presence of pertussis toxin, lymphocyte locomotor responses to attractants become insensitive to pertussis toxin.
Bacteriology and Immunology Department, University of Glasgow, Western Infirmary, U.K.
P C
PC
Wilkinson
E A
EA
Watson
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001402:B-Lymphocytes / Q000502:physiology; D002455:Cell Division / Q000502:physiology; D002465:Cell Movement / Q000187:drug effects*; D002478:Cells, Cultured; D002630:Chemotactic Factors / Q000037:antagonists & inhibitors; D002634:Chemotaxis, Leukocyte / Q000187:drug effects; D006801:Humans; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D008214:Lymphocytes / Q000502:physiology*; D037342:Pertussis Toxin; D013601:T-Lymphocytes / Q000502:physiology; D016559:Tacrolimus; D013997:Time Factors; D010566:Virulence Factors, Bordetella / Q000494:pharmacology*
D000900:Anti-Bacterial Agents; D002630:Chemotactic Factors; D007166:Immunosuppressive Agents; D010566:Virulence Factors, Bordetella; D037342:Pertussis Toxin; D016559:Tacrolimus