Nicole Zhao ’20

Alzheimer’s disease is a progressive neurodegenerative disease that destroys memory and thinking skills (1). When the disease was classified by Dr. Alzheimer in 1906, he noticed that the brain tissue of his patient with early-onset Alzheimer’s was riddled with amyloid-β plaques and tangles. Tangles are jumbled bundles of fibers inside neurons that disrupt the ability of neurons to communicate with each other (1). These tangles are made of hyperphosphorylated and pathological forms of tau, a protein associated with microtubules, and normally stabilizes the structure of neurons (2). So far, there is no FDA-approved treatments that cures, slows, or prevents pathologies involving the accumulation of tau proteins. 

Recently, researchers at the University of New Mexico have engineered a vaccine containing virus-like particles (2). Although these particles cannot replicate, the immune system will recognize its surface proteins as invaders and manufacture antibodies to mark them for elimination. Therefore, it can be reasoned that this vaccine can prime our immune system to fight hyperphosphorylated tau protein. Researchers have also shown that this vaccine can cause the immune system to produce antibodies against the aggregation of this tau protein in two mouse models. It was found that this immune response was sustainable after three injections of the vaccine into the mice muscles (2). 

Not only did the vaccine target hyperphosphorylated tau protein, it also avoided pro-inflammatory cell responses which could have otherwise caused more damage (2). Pro-inflammatory responses include the release of small proteins called cytokines which affect the interactions between cells, causing inflammation and sometimes death (3). In experiments with mouse models with Alzheimer’s disease, the vaccine was shown to prevent atrophy in the hippocampus and corpus callosum in their brains (2). This is indubitably very interesting since the hippocampus of patients with Alzheimer’s deteriorates as the disease progresses (4). 

Although there is prevalent speculation about what Alzheimer’s disease encompasses and what causes it, this study is important because it provides a premise for arming the immune system against tau protein that can aggregate in the brain. Since this is one of the symptoms of Alzheimer’s disease, this therapy shows promise for disease prevention.

References:

1. What is Alzheimer’s Disease? National Institute on Aging, (2017). 
2. N. M. Maphis, et al., Qß Virus-like particle-based vaccine induces robust immunity and protects against tauopathy. Nature Partner Journals Vaccines 4 (2019). doi: 10.1038/s41541-019-0118-4. 
3. J. Zhang, et al., Cytokines, inflammation and pain. International Anesthesiology Clinics 45, 27-37 (2007). doi: 10.1097/AIA.0b013e318034194e. 
4. Y. Mu. Adult hippocampal neurogenesis and its role in Alzheimer’s disease. Molecular Neurodegeneration 6, 85 (2011). doi: 10.1186/1750-1326-6-85.
5. Image retrieved from: https://torange.biz/vaccine-18876