Oral tolerance elicited in mice by beta-lactoglobulin entrapped in biodegradable microspheres

Oral administration of antigen is known to be appropriate for some vaccine purposes as well as oral tolerance induction. In the present study, oral ad ministration of beta-lactoglobulin (BLC) loaded poly(D,L-lactide-co-glycoli de) (D,L-PLG) microspheres induced tolerance was evaluated. A single feedin g of 5 mu g of encapsulated BLG tolerised BALB/c mice to subsequent BLG par enteral challenge, suppressing the specific humoral, intestinal and cellula r responses. The tolerogenic efficient dose was then reduced 10,000 times, compared to oral administration of soluble BLG. This suggests that loading food proteins into D,L-PLG microspheres might be a potential tool for induc ing oral tolerance with allergens. (C) 2000 Elsevier Science Ltd. All right s reserved.