CpG DNA Therapy For Alzheimer Disease

Alzheimer disease is the most common form of dementia, affecting approximately 1.6% of the population in the United States (nearly 19% in the 75-84 age group). It is an incurable, degenerate, and terminal disease thought to be caused by accumulation of oligomeric amyloid β (oAβ).

Microglia are the resident immune cells in the central nervous system; they remove damaged neurons, plaques, and infectious agents from the brain and spinal cord. Microglia cluster around senile Aβplaques in Alzheimer disease patients; however, the role of microglia in oAβtoxicity remains unclear. Doi et al discovered that microglial activation with unmethylated CpG DNA, which binds to an immune receptor on microglia, prevented oAβtoxicity and enhanced oAβ peptide clearance in culture. Furthermore, injection of CpG DNA directly into the brain mitigated both cognitive impairment and learning defects in a mouse model of Alzheimer disease. CpG DNA may therefore be a therapeutic candidate for treatment of Alzheimer disease.

Dr. Doi and colleagues conclude that "CpG, especially class B and C, may also be effective therapeutic agents against oAβ1-42 neurotoxicity in [Alzheimer disease]."