CD28-MEDIATED ACTIVATION IN CD45RA(-CELLS - ENHANCED LEVELS OF REACTIVE OXYGEN INTERMEDIATES AND C-REL NUCLEAR TRANSLOCATION IN CD45RA(+) CELLS() AND CD45RO(+) T)

We have analyzed the effect of complete T cell activation (anti-CDS pl us anti-CD28) on the activation of NF-kappa B in CD45RA(+) (naive) and CD45RO(+) (memory/effector)T cells. Long exposure (24 h) induced stro nger NF-kappa B DNA binding in CD-45RA(+) cells than in CD45RO(+) cell s. Analysis of the nuclear c-Rel protein indicated that after anti-CD3 (+) anti-CD28 stimulation the level of c-Rel was higher in CD45RA(+) c ells. Analysis of the cytoplasmic inhibitor I kappa B alpha indicated that anti-CD3(+) anti-CD28 stimulation induced a long-lasting degradat ion in CD45RA(+) cells but in CD45RO(+) cells the degradation process was more rapid. Because the CD28 costimulus is known to induce the pro duction of reactive oxygen intermediates (ROIs), the intracellular ROI levels in CD45RA(+) and CD45RO(+) cells were compared by flow cytomet ry. ROIs were produced in both cell types, but more strongly in CD45RA (+) cells. The data presented in this study further emphasize the diff erences between CD45RA(+) and CD45RO(+) T lymphocytes in ROI-dependent signaling pathways.