Mannans can produce either stimulation or suppression of the antibody response to Type III pneumococcal polysaccharide (SSS-III) and sheep erythrocytes (SRBC); the effect produced depends upon the concentration, molecular size, and chemical composition of the preparation of mannan used. These immuno modulatory effects appear to be T cell dependent since they are not demonstrable in athymic nude mice and the mannans used do not induce the non-specific proliferation of B lymphocytes.
