A common vaccine for fighting neurodegenerative disorders: recharging immunity for homeostasis.

Neurodegenerative conditions share common primary risk factors and mediators of disease progression. Because many degenerative disorders are age related, deteriorating immunity in aging patients might impose additional risk. Adaptive (T-cell-mediated) immunity is a defense mechanism that instructs microglia to fight off and clear away self-derived enemies. Such adaptive immunity can be boosted, without risking the development of autoimmune disease, by injecting weak agonists of self-antigens or by weakening the suppressive CD4+CD25+ regulatory T cells. If widely cross-reactive, the agonist might effectively counteract a variety of neurodegenerative disorders. Boosting of relevant T cells by vaccination could thus "recharge" a deteriorating immune system that has to contend with an increasing number of risk factors.