(1-]3)-BETA-D-GLUCAN AND ENDOTOXIN MODULATE IMMUNE-RESPONSE TO INHALED ALLERGEN

EXPOSURE to dust may involve co-exposure to agents which are allergens , together with those which are pro-inflammatory. To study the effects of such a coexposure, the humoral and inflammatory responses were stu died in guinea pigs inhaling the T-cell-dependent antigen ovalbumin (O VA) and the inflammatory agents (1 --> 3)-beta-D-glucan and lipopolysa ccharide (LPS). The effects were evaluated as inflammatory cells in th e lung and serum antibodies to OVA. LPS caused a stimulation of the OV A-induced antibody production which was abolished by simultaneous expo sure to (1 --> 3)-beta-D-glucan. An increase of eosinophils after OVA exposure was decreased by coexposure to (1 --> 3)-beta-D-glucan. The r esults demonstrate a complex interaction between adaptive and innate i mmune mechanisms in the lung, determined by exposure to common contami nants in airborne dust.