Suppression of humoral immune response in mice by administration of high molecular levan.

High molecular levan, a polyfructoside, has a dose-dependent inhibitory effect on the primary immune response to sheep red cells (SE) in Balb/c mice, when given as from 1--2 days prior to the antigen injection. A slight stimulation of the immune response was observed when levan was given shortly before or 1 day after the antigen.