Low-dose intragastric administration of Phaseolus vulgaris agglutinin (PHA) does not induce immunoglobulin E (IgE) production in Sprague-Dawley rats

Native Phaseolus vulgaris agglutinin (PHA) poses a potential health threat, when ingested with improperly cooked red kidney beans. Since PHA triggers human basophilic granulocytes in culture to rapidly release considerable amounts of interleukin-(IL-)4 and IL-13, key cytokines for inducing immunoglobulin E (IgE) production, the question was addressed whether this lectin can evoke in vivo IgE production. IgE-low-responder (Sprague-Dawley) rats received PHA (6 mg/rat/day) intragastrically by gavage over a period of 10 days. Up to day 35, there was no IgE induction regardless of whether the animals were boostered subcutaneously with PHA or not, indicating that PHA cannot be regarded as a general IgE inducer in rats.