Cell-Based Therapies For Neurological Disease

The prospect of treating patients suffering from neurodegenerative diseases such as Alzheimer's and Parkinson's with gene therapy has moved a step closer, with three companies reporting encouraging results in primate studies at the the annual meeting of the American Society of Neurosciences in Miami, USA, on November 15.

The first approach, by researchers Dwaine Emerich and Jeffrey Kordower of US biotechnology company CytoTherapeutics, extends work carried out by Tuszynski et al of the University of California at San Diego which shows that skin cells genetically modified to produce human nerve growth factor, which are transplanted into the brains of monkeys modified to mimic AD, can prevent the loss of cholinergic neurons.

Using genetically-engineered cells from the kidneys of baby hamsters, Cyto-Therapeutics Inc has also demonstrated that hNGF can prevent the degeneration of cholinergic neurons and, for the first time, monkeys were included in the trials who were equivalent in age to 78-87-year-old humans. The engineered cells were placed in polymer capsules, which permit the entry of nutrients and oxygen and therapeutic levels of NGF to leave the capsule, while protecting the cells within it from attack by the host immune system. Control monkeys received non-modified encapsulated cells.