Determination of protein allergenicity: studies in mice

There is a need to identify and characterize the allergenic potential of novel proteins introduced into genetically-modified crop plants. Although several approaches have already been described, none of these measures directly the ability of proteins to cause allergic sensitization. For this reason there has been a growing interest in the development of suitable animal models. This article describes experience to date with a method based upon assessment of serological (IgG and IgE antibody) responses induced in BALB/c strain mice by proteins. Comparisons have been made between intraperitoneal (i.p.) administration and exposure by gavage using both allergenic and non-allergenic proteins. The available data indicate that responses provoked by i.p. exposure permit the identification of proteins that have the inherent potential to induce IgE antibody production and allergic sensitization. Moreover, this approach also provides a rank order of proteins with respect to allergenic potency that apparently reflects what is known of their relative sensitizing activity in humans. By comparison, oral exposure of mice by gavage is somewhat less sensitive. On this basis it is proposed that the inherent sensitizing potential of novel proteins can be evaluated as a function of IgE antibody responses stimulated by parenteral (i.p.) exposure of BALB/c mice.