Vitamin E effects on in vitro immunoglobulin M and interleukin-1 beta production and transcription in dairy cattle

Experiments were conducted to determine the effect of dietary vitamin E on in vitro IgM and interleukin-1 production and its transcription by bovine peripheral blood mononuclear cells. Cells were isolated from Jersey cows and cultured with pokeweed mitogen, a T-cell-dependent, B-lymphocyte mitogen, to stimulate polyclonal IgM production. Addition of 55 and 110 ng/ml of alpha-tocopherol at time 0 to cell cultures containing pokeweed mitogen significantly enhanced IgM production compared with control cultures containing pokeweed mitogen alone. Cultures supplemented with 55 ng/ml of alpha-tocopherol at 0, 24, or 48 h after incubation with mitogen had enhanced IgM production compared with control cultures incubated for the same duration. However, addition of alpha-tocopherol to cultures at 72 and 96 h did not affect IgM production. Production of interleukin-1 in culture supernatants obtained 24 h after stimulation with pokeweed mitogen was similar between control cultures and cultures supplemented with alpha-tocopherol. At 48 h, secretion of interleukin-1 was maintained in the supplemented cultures but declined in control cultures. Mononuclear cells obtained from steers receiving vitamin E supplement or control steers were used to examine the effects of in vivo vitamin E status on interleukin-1 mRNA expression. Concanavalin A-stimulated cells from Jersey steers fed diets supplemented with vitamin E expressed 55% higher interleukin-1 mRNA than cells from control steers.