Oral administration of IL-12 suppresses anaphylactic reactions in a murinemodel of peanut hypersensitivity

There is no satisfactory therapeutic intervention for peanut allergy, which accounts for most life-threatening food allergic reactions. Since IL-12 ha s been found to inhibit allergic airway responses in a mouse model of asthm a and to cure Th2 cytokine-mediated murine schistosomiasis, we hypothesized that IL-12 treatment might also inhibit peanut allergic reactions. Consequ ently, we investigated the effects of oral IL-12 treatment in a murine mode l of peanut allergy and found that oral administration of liposome encapsul ated rIL-12 could both prevent and reverse peanut hypersensitivity and coul d reduce histamine release, peanut-specific serum IgE and IgG1, and fecal I gA levels. Oral IL-12 treatment also increased IFN-gamma but did not decrea se IL-4 or IL-5 levels. We conclude that oral rIL-12 treatment has therapeu tic as well as preventive effects on peanut allergy, which are associated w ith increased IFN-gamma production. (C) 2001 Academic Press.