Ethanol-induced suppression of cell-mediated immunity in the mouse

Among its many effects on multiple organ systems, ethanol abuse also elicits potent immunomodulatory effects as well. Increased susceptibility to disease as well as increased severity in infection is well documented in alcoholics and may be related to an altered immune response. A mouse model has been developed in which C57Bl/6 mice are fed a nutritionally adequate liquid diet in which ethanol provides 27% of total calories (3.75% ethanol) in order to examine the effects of short-term, low dose ethanol administration on cell mediated immunity. All mice were evaluated for percentage of plasma ethanol, impaired motor skills and impaired delayed type hypersensitivity to sheep erythrocytes. Animals fed the ethanol diet for 5, 10, or 15 days evidenced plasma ethanol concentrations between 0.13% and 0.23% as well as significantly impaired motor skills. Mice maintained on the ethanol diet 8 days prior to erythrocyte sensitization and on the 6 days between sensitization and challenge demonstrated a significant reduction of 58% in footpad swelling. Moreover, mice fed ethanol for only the 6 days between erythrocyte sensitization and challenge also demonstrated a significant decrease of 35% in this delayed type immune response. However, animals administered ethanol prior to sensitization and then switched to control diet between sensitization and challenge evidenced a normal cell-mediated immune response to the sheep erythrocytes. Thus, it appears that the critical time of low dose ethanol-induced immunosuppression is between immunogen sensitization and challenge.