Vitamin E and immune response. I. Enhancement of helper T cell activity by dietary supplementation of vitamin E in mice.

The effects of vitamin E on the humoral immune response to hamster erythrocytes (HRBC) and 2,4,6-trinitrophenyl (TNP) were studied in mice. Inbred SL mice were fed on a diet supplemented with 0, 20 or 200 mg of vitamin E per kg of food throughout the course of experiments. These mice were immunized primarily with HRBC 50 days after the beginning of treatment with vitamin E supplementation. Secondary immunization with TNP—HRBC, a hapten-carrier conjugate, was given 28 days after primary immunization with HRBC. Anti-HRBC and anti-TNP haemagglutinin titres were increased by supplementing mice with vitamin E. Moreover, the effect of previous priming of mice with HRBC on the hapten-specific antibody response to immunization with TNP-HRBC was also enhanced by vitamin E supplementation. These effects of vitamin E were dose-dependent, and vitamin E as tocopheryl acetate exerted more effect than vitamin E as tocopheryl nicotinate. In experiments with the mouse inbred strain DDD, vitamin E seemed to facilitate the shift of antibody production from IgM to IgG. Initial IgM response and late IgG response were not augmented by treating mice with vitamin E supplementation. These findings suggested that vitamin E stimulated the helper activity of T lymphocytes. This was confirmed using an adoptive transfer system involving stimulation of hapten-primed cells by a hapten-carrier conjugate in the presence of carrier-primed helper cells.