OXIDATIVELY MODIFIED LOW-DENSITY-LIPOPROTEIN IS A CHEMOATTRACTANT FORHUMAN T-LYMPHOCYTES

Oxidatively modified low density lipoprotein (Ox-LDL) is a known chemo attractant for monocytes. Here we demonstrate, using a modified Boyden chamber assay, that human peripheral blood T lymphocytes, but not B l ymphocytes, also respond chemotactically to Ox-LDL, showing a threefol d increase over control and an optimum response at 10 mug/ml. Copper a nd endothelial cell-oxidized LDL and beta-VLDL were used and gave simi lar results. The activity was not chemokinetic and native LDL possesse d no chemoattractant activity. The chemoattractant activity was found to reside in the lipid fraction of Ox-LDL. Lysophosphatidylcholine is a major phospholipid component of Ox-LDL and is known to be chemotacti c for monocytes. We show that lysophosphatidylcholine is also chemotac tic for T lymphocytes with a maximal fourfold increase at 10 muM. Nonm etabolizable analogues of lysophosphatidylcholine had no such chemotac tic effect. Thus, Ox-LDL, by virtue of its lysophosphatidylcholine con tent, may contribute to the recruitment of both T lymphocytes and mono cytes into developing atherosclerotic lesions.