New research has found that a new vaccine that targets neurotoxic forms of the peptide amyloid beta (oligomeric Aβ) could help halt the progression of Alzheimer’s disease, one of the most common age-related neurological disorders.
Researchers from the University of South Florida Health (USF Health) have been focusing on how to get rid of excess inflammation and other complications that affect the development of a potential Alzheimer’s vaccine.
Now, a preclinical study, led by Dr. Chuanhai Cao and his colleagues, has shown that an “antigen-presenting dendritic vaccine with a specific antibody response to oligomeric Aβ” may be safer and offer benefits in treating Alzheimer’s disease.
The vaccine, known as E22W42 DC, is based on immunotherapy, which uses immune cells called dendritic cells (DC) packed with a modified Aβ peptide as the antigen.
The preclinical findings of this novel vaccine were published online last week in the Journal of Alzheimer’s Disease.
Lead author Dr. Cao said, “This therapeutic vaccine uses the body’s own immune cells to target the toxic Aβ molecules that accumulate harmfully in the brain. And, importantly, it provides strong immunomodulatory effects without inducing an unwanted, vaccine-associated autoimmune reaction in the aging mice.”
Previous clinical studies of all anti-amyloid treatments for the neurodegenerative disease have failed, including a potential vaccine trial targeting Aβ (AN-1792), which was halted in 2002 after the participants developed the inflammation of the central nervous system.
Dr. Cao explained, “Inflammation is a primary symptom of Alzheimer’s disease, so any possible treatment with neural inflammation as a side effect essentially pours gas on the fire.”
He said a next-generation anti-amyloid vaccine for Alzheimer’s disease would produce “long-lasting, moderate antibody levels needed to prevent Aβ oligomers from further aggregating into destructive Alzheimer’s plaques, without over-stimulating the immune systems of elderly people.”
In the current study, the researchers tested the vaccine formulated by using modified Aβ-sensitized DC derived from the bone marrow of the mouse.
“Because we use dendritic cells to generate antibodies, this vaccine can coordinate both innate and acquired immunity to potentially overcome age-related impairments of the immune system,” Dr. Cao explained.
The researchers found that the new vaccine slowed memory impairment in mice with Alzheimer’s. Also, the mice who received the experimental vaccine showed significantly fewer errors in working memory. Memory loss is one of the characteristic symptoms of Alzheimer’s, which makes it difficult to learn and retain new information. The study authors also said the vaccine developed for patients with Alzheimer’s can potentially strengthen the immune system of older patients.