Immune Response to Alzheimer's Protein Improves with Age

Researchers seeking to develop a vaccine to prevent Alzheimer's disease have found that some elderly individuals, as well as those with the disease, have elevated levels of T-cells reactive towards Abeta, the amyloid b protein that accumulates and injures the brain.

A vaccine basted on Abeta has been shown to be effective in animals, but clinical trials in humans were terminated when some of the test subjects developed meningoencephalitis.

Investigators from Harvard Medical School (Boston, MA, USA) reported in the August 1, 2003, issue of the Journal of Clinical Investigation that they had measured cellular immune responses to Abeta in middle-aged and elderly healthy subjects and in patients with Alzheimer's disease. They found that a significantly higher proportion of healthy elderly subjects and patients with Alzheimer's disease had strong Abeta-reactive T-cell responses than occurred in middle-aged adults. The immunodominant Abeta epitopes in humans resided in amino acids 16–33.

The authors concluded by saying, "The occurrence of intrinsic T-cell reactivity to the self-antigen Abeta in humans has implications for the design of Abeta vaccines, may itself be linked to Alzheimer's disease susceptibility and course, and appears to be associated with the aging process.”




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Harvard University Medical School