EFFECTS OF RRR-ALPHA-TOCOPHERYL SUCCINATE ON IL-1 AND PGE(2) PRODUCTION BY MACROPHAGES

Vitamin E is thought to enhance immunity by increasing interleukin-1 ( IL-1) production and by downregulating prostaglandin E2 (PGE2) synthes is. In an effort to understand the mechanism(s) whereby the form of vi tamin E known as RRR-alpha-tocopheryl succinate [also called vitamin E succinate (VES)] ameliorates retrovirus-induced immune dysfunctions, peritoneal exudate cells (PECs) derived from normal chickens and avian and murine macrophage cell lines were used as in vitro model systems to test the effects of VES treatments on PGE2 and IL-1 production. Sup ernatants from PECs that were exposed to avian erythroblastosis virus (AEV) for 45 minutes exhibited a 256% increase in PGE2 levels compared with supernatants from replica cultures of PECs not exposed to AEV. P retreatment of PECs with VES before exposure to AEV maintained PGE2 le vels at normal control levels. VES treatment enhanced IL-1 production by avian (HD11) and murine (P388D1) macrophage cells, respectively. Su pernatants from VES-treated HD11- and P388D1-stimulated cells containe d IL-1 activity 196% and 385%, respectively, greater than that observe d with supernatants from untreated control cells. On the basis of thes e studies, downregulation of retrovirus-induced PGE2 production and/or upregulation of IL-1 production by VES are potential mechanisms for V ES amelioration of retrovirus-induced immune suppression.