A link between catalytic activity, IgE-independent mast cell activation, and allergenicity of bee venom phospholipase A2.

摘要: The molecular and cellular mechanisms controlling Ab isotype selection following encounter of a given Ag are still unclear, although the regulatory role cytokines is established. In present study we explored possibility that nonimmunologic interaction an allergen with cells innate immune system might result in release mediators promote IgE adaptive responses. Using bee venom phospholipase A2 (PLA2) mutant variant lacking enzymatic function, show PLA2, but not its catalytically inactive variant, able to induce IgE-independent mediator release, including IL-4, from rodent mast cells. Assessing vivo relevance these observations, find repeated injections low doses active enzyme into mice synthesis high levels PLA2-specific IgE, while immunization form yields no detectable response. Both Ags were similarly immunogenic when used for immunization. These findings suggest be source IL-4 at onset specific immunity against sources allergens such as contain PLA2 support concept biologic action on can play determining