APOLIPOPROTEIN-E INHIBITION OF PROLIFERATION OF MITOGEN-ACTIVATED T-LYMPHOCYTES - PRODUCTION OF INTERLEUKIN-2 WITH REDUCED BIOLOGICAL-ACTIVITY

Apolipoprotein E (apoE), but not apoAI or apoCIII, suppresses mitogen- activated T lymphocyte proliferation, independent of the type of activ ation signal. Both CD4 and CD8 T cells are inhibited. ApoE inhibits T cell proliferation, in part, by reducing the production of bioactive i nterleukin 2 (IL2). IL2 activity is reduced by similar to 50-65% in cu ltures of mitogen-stimulated T cells when apoE is present. ApoE does n ot significantly alter levels of IL2 mRNA or the mass of secreted IL2 protein, quantitated by enzyme immunoassay. Reduced IL2 activity was n ot a consequence of induction of IL2 inhibitors in response to apoE or effects of apoE on the bioassay. These results suggest that apoE anta gonizes post-translational events in mitogen-activated T lymphocytes t hat are required for the secretion of a bioactive IL2 protein. (C) 199 4 Academic Press. Inc.