A role for impaired regulatory T cell function in adverse responses to aluminum adjuvant-containing vaccines in genetically susceptible individuals

Regulatory T cells play a critical role in the immune response to vaccination, but there is only a limited understanding of the response of regulatory T cells to aluminum adjuvants and the vaccines that contain them. Available studies in animal models show that although induced T regulatory cells may be induced concomitantly with effector T cells following aluminum-adjuvanted vaccination, they are unable to protect against sensitization, suggesting that under the Th2 immune-stimulating effects of aluminum adjuvants, Treg cells may be functionally compromised. Allergic diseases are characterized by immune dysregulation, with increases in IL-4 and IL-6, both of which exert negative effects on Treg function. For individuals with a genetic predisposition, the beneficial influence of adjuvants on immune responsiveness may be accompanied by immune dysregulation, leading to allergic diseases. This review examines aspects of the regulatory T cell response to aluminum-adjuvanted immunization and possible genetic susceptibility factors related to that response.