Alteration of membrane phospholipid methylation by adenosine analogs does not affect T lymphocyte activation.
Membrane phospholipid methylation has been described during activation of various immune cells. Moreover recent data indicated modulation of immune cells functions by adenosine. As S-Adenosyl-methionine and S-Adenosyl-homocysteine are adenosine analogs and modulators of transmethylation reactions, the effects of SAH and SAM were investigated on membrane phospholipid methylation and lymphocyte activation. SAM (10(-5) M) was shown to induce the membrane phospholipid methylation as assessed by the 3H-methyl-incorporation in membrane extract. This effect was inhibited by SAH. In contrast SAM and SAH did not affect the phytohemagglutinin-induced proliferative response of peripheral blood mononuclear cells. SAH neither modified the early internalization of membrane CD3 antigens nor did it prevent the late expression of HLA-DR antigens on lymphocytes activated by phytohemagglutinin. These results indicate that in vitro alteration of phospholipid methylation does not affect subsequent steps of human T lymphocyte activation and proliferation.
Gormand
F
F
Service de Pneumologie, Centre Hospitalier Lyon Sud, Pierre Bénite, France.
Cordier
G
G
Fonlupt
P
P
Pacheco
Y
Y
Revillard
J P
JP
D000241:Adenosine / Q000494:pharmacology; D000941:Antigens / Q000276:immunology; D000945:Antigens, Differentiation, T-Lymphocyte / Q000502:physiology; D017252:CD3 Complex; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D002478:Cells, Cultured; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D008055:Lipids / Q000097:blood; D008213:Lymphocyte Activation / Q000187:drug effects* / Q000502:physiology; D008285:Major Histocompatibility Complex / Q000276:immunology; D008745:Methylation; D010743:Phospholipids / Q000097:blood*; D011948:Receptors, Antigen, T-Cell / Q000502:physiology; D012435:S-Adenosylhomocysteine / Q000494:pharmacology*; D012436:S-Adenosylmethionine / Q000494:pharmacology*; D013997:Time Factors; D014316:Tritium
D000941:Antigens; D000945:Antigens, Differentiation, T-Lymphocyte; D017252:CD3 Complex; D008055:Lipids; D010743:Phospholipids; D011948:Receptors, Antigen, T-Cell; D014316:Tritium; D012436:S-Adenosylmethionine; D012435:S-Adenosylhomocysteine; D000241:Adenosine