EFFECTS OF DIETARY VITAMIN-E AND SELENIUM ON IN-VITRO CELLULAR IMMUNE-RESPONSES IN CATTLE

Four groups of calves depleted of alpha-tocopherol and selenium (Se) w ere supplemented with alpha-tocopherol or Se or alpha-tocopherol and S e or received no supplement. In vitro lymphocyte proliferative respons es were measured in fetal calf serum (FCS), in autologous serum and in pooled sera from each group. In FCS, the responses to pokeweed mitoge n were significantly enhanced for calves supplemented with alpha-tocop herol. In autologous serum, the mean responses to keyhole limpet haemo cyanin (KLH) were greatest for calves supplemented with Se alone. In p ooled sera from each group, lymphocytes from calves supplemented with Se alone showed enhanced responses to KLH in the presence of serum fro m calves supplemented with cc-tocopherol. The calves depleted of alpha -tocopherol had increased circulating percentages of BoCD2 lymphocytes , apparently due to changes in the BoCD4 subpopulation. The percentage s of B cells were greatest in calves supplemented with alpha-tocophero l and Se. The results indicate that alpha-tocopherol and Se have inter active effects on lymphocyte responses to antigen and suggest that mic ronutrient status is important when interpreting the results of in vit ro assays of lymphocyte function.