VITAMIN-E SUPPLEMENTATION AT VARIOUS LEVELS ALTERS CYTOKINE PRODUCTION BY THYMOCYTES DURING RETROVIRUS INFECTION CAUSING MURINE AIDS

Female C57BL/6 mice were infected with LP-BM5 retrovirus, causing muri ne AIDS which is functionally similar to human AIDS. Retrovirus infect ion targets the thymus producing altered T-cell differentiation via th e dysregulation of thymocyte cytokine production. Therefore the effect s of dietary vitamin E at various levers were determined on cytokine p roduction by ConA-stimulated thymocytes from uninfected (normal) and r etrovirus-infected mice. Dietary supplementation, with a 15-, 150- and 450-fold increase of vitamin E in the diet modulated interleukin-2 (I L) production in both uninfected mice and retrovirus-infected mice. Th e 150- and 450-fold vitamin E supplementation significantly reduced IL -4 secretion by thymocytes from the uninfected, normal mice. Supplemen tation at all levels also significantly reduced IL-4 production by thy mocytes, which was elevated by the retrovirus infection. Vitamin E sig nificantly reduced IL-6 and interferon-gamma production increased duri ng the progression to murine AIDS. The effects of dietary vitamin E on conA-induced proliferation of thymocytes were consistent with the fin ding on changes of IL-2 secretion. No effect of dietary vitamin E on t hymus weight was observed in both uninfected and retrovirus-infected m ice. These data indicate that dietary vitamin E supplementation at ext remely high levels can modulate cytokine production by thymocytes. Thi s could affect T-cell differentiation, especially during murine AIDS w hen cytokine production was partially normalized by vitamin E suppleme ntation.