Inhibition of phosphatidylserine synthesis induced by a CD4 mAb, B66.6 in Jurkat T cells.
A monoclonal antibody, B66.6, previously classified in the cluster of differentiation 4 (CD4), has been studied and compared with another CD4 monoclonal antibody, IOT4. It was found that B66.6 but not IOT4 was able to mobilize Ca2+ from intracellular stores in the Jurkat T cell line. Ca2+ mobilization was followed by a decrease in the extent of phosphatidylserine synthesis. In the presence of the phorbol ester, phorbol 12,13-dibutyrate, B66.6 induced interleukin-2 synthesis. Altogether, the results indicate that the CD4 monoclonal antibody, B66.6, mimics other T cell activators such as CD3 and confirm that the inhibition of phosphatidylserine synthesis in activated T cells follows the mobilization of Ca2+ from intracellular stores and is independent of the activation of the Ca(2+)-and phospholipid-dependent protein kinase C.
INSERM U210, Faculté de Médecine, Nice, France.
C
C
Aussel
J P
JP
Breittmayer
C
C
Pelassy
S
S
Carrel
D000911:Antibodies, Monoclonal / Q000276:immunology*; D015703:Antigens, CD / Q000276:immunology; D000945:Antigens, Differentiation, T-Lymphocyte / Q000276:immunology; D018801:CD2 Antigens; D017252:CD3 Complex / Q000276:immunology; D015704:CD4 Antigens / Q000276:immunology*; D002118:Calcium / Q000378:metabolism / Q000502:physiology; D002460:Cell Line; D006801:Humans; D007376:Interleukin-2 / Q000032:analysis / Q000096:biosynthesis; D008213:Lymphocyte Activation / Q000276:immunology*; D010718:Phosphatidylserines / Q000096:biosynthesis*; D011971:Receptors, Immunologic / Q000276:immunology; D013601:T-Lymphocytes / Q000378:metabolism*
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D018801:CD2 Antigens; D017252:CD3 Complex; D015704:CD4 Antigens; D007376:Interleukin-2; D010718:Phosphatidylserines; D011971:Receptors, Immunologic; D002118:Calcium