The activation of protein kinase C is not necessary for the monoclonal antibody-induced modulation of CD3 and CD4 antigens.
We studied the effect of staurosporine, a potent inhibitor of protein kinase C (PKC) activity, on the phorbol ester- or monoclonal antibody (mAb)-induced modulation of CD3 and CD4 surface antigens. Staurosporine (10(-5) M) completely inhibited phorbol ester-induced modulation but had no effect on that induced by mAb. These results indicate that the down-regulation of CD3 and CD4 observed after activation of the cells by the corresponding mAb is independent from PKC-mediated phosphorylations, and thus that the activation of PKC is sufficient but not necessary to induce the modulation of CD3 and CD4 antigens.
Thuillier
L
L
INSERM U 75 and U 132, Hôpital Necker-Enfants Malades, Paris, France.
Selz
F
F
Métézeau
P
P
Pérignon
J L
JL
D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D000470:Alkaloids / Q000494:pharmacology; D000911:Antibodies, Monoclonal; D015703:Antigens, CD / Q000378:metabolism*; D000945:Antigens, Differentiation, T-Lymphocyte / Q000378:metabolism*; D017252:CD3 Complex; D015704:CD4 Antigens / Q000378:metabolism*; D015536:Down-Regulation / Q000187:drug effects / Q000502:physiology; D004789:Enzyme Activation / Q000502:physiology; D006801:Humans; D066298:In Vitro Techniques; D007546:Isoquinolines / Q000494:pharmacology; D008214:Lymphocytes / Q000378:metabolism; D010879:Piperazines / Q000494:pharmacology; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000502:physiology*; D011948:Receptors, Antigen, T-Cell / Q000378:metabolism*; D019311:Staurosporine
D000470:Alkaloids; D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D017252:CD3 Complex; D015704:CD4 Antigens; D007546:Isoquinolines; D010879:Piperazines; D011948:Receptors, Antigen, T-Cell; D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D011493:Protein Kinase C; D019311:Staurosporine