Induction of tolerance and cross-tolerance to methacrylate contact sensitizers

Induction of immunological tolerance to contact allergens might prevent und esired sensitization, in particular to occupational sensitizers, e.g., meth acrylates (MA). Here, using a guinea pig model, we studied to which extent tolerance to one methacrylate might result in cross-tolerance to other cong eners. Strong tolerance to the monomethacrylates hydroxy-ethyl MA (HEMA) an d methyl AIA, but not to the dimethacrylate ethylene-glycol MA (EGDMA) coul d be induced. The induced tolerance was stable, could not be broken by repe ated sensitization attempts, and was mediated by specific suppressor cells, as demonstrated in T cell transfer experiments. In HEMA-tolerized animals, strong cross-tolerance to methacrylate congeners, including EGDMA, itself being nontolerogenic and showing the lowest cross-reactivity to HEMA, was f ound. Thus, oral application of contact allergens, to which skin contact ca nnot be avoided, e.g., in occupational settings, can induce broad cross-tol erance to related substances and might offer a promising preventive approac h. (C) 2001 Academic Press.