CD2 triggering stimulates the formation of platelet-activating factor-acether from alkyl-arachidonoyl-glycerophosphocholine in a human CD4+ T lymphocyte clone.
A human CD4+ T lymphocyte clone synthesized platelet-activating factor (PAF) acether when stimulated via the CD2 pathway. PAF-acether was characterized by biochemical and biophysical properties and precursor-product relationships (alkyl-acyl-sn-glycero-3-phosphocholine (GPC)----alkyl-lyso-GPC (lyso-PAF)----PAF-acether) were demonstrated. The clone contained substantial amounts of alkyl-acyl-GPC. i) Hydrolysis of alkyl-acyl-GPC upon CD2 stimulation was evidenced: [3H]alkyl-lyso-GPC was formed from [3H]alkyl-acyl-GPC in [3H] alkyl-labeled cells; alkyl-lyso-GPC production was also bioassayed after CD2 triggering. ii) The rate of arachidonate transfer from diacyl-GPC to alkyl-acyl-GPC increased after CD2 stimulation of the [3H]arachidonate-labeled P28D T cells, demonstrating alkyl-lyso-GPC formation. iii) Comparison of the molecular species of the produced PAF-acether with those of arachidonate-containing alkyl-acyl-GPC raises the possibility that the produced PAF-acether is related to alkyl-arachidonoyl-GPC.
Le Gouvello
S
S
CNRS UA 0186, C.H. Pitié-Salpètrière, Paris, France.
Vivier
E
E
Debre
P
P
Thomas
Y
Y
Colard
O
O
D000945:Antigens, Differentiation, T-Lymphocyte / Q000502:physiology*; D001095:Arachidonic Acids / Q000378:metabolism; D018801:CD2 Antigens; D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism*; D002478:Cells, Cultured; D006801:Humans; D066298:In Vitro Techniques; D010713:Phosphatidylcholines / Q000378:metabolism; D010767:Phosphorylcholine / Q000031:analogs & derivatives / Q000378:metabolism; D010972:Platelet Activating Factor / Q000096:biosynthesis*; D011971:Receptors, Immunologic / Q000502:physiology*; D015398:Signal Transduction
D000945:Antigens, Differentiation, T-Lymphocyte; D001095:Arachidonic Acids; D018801:CD2 Antigens; D010713:Phosphatidylcholines; D010972:Platelet Activating Factor; D011971:Receptors, Immunologic; D010767:Phosphorylcholine