The immune system is a very complex conglomerate of specific molecules that are able to identify and modify specific factors both inside and outside the cells.

Tricking the System

Sometimes, it is possible to trick the immune system into attacking proteins that cause neurological diseases by vaccinating the patients against these proteins. Although this approach has shown some promise in, for example, Alzheimer’s disease, there are still some risks involved since it is a relatively new technique and many aspects of it have yet to be described accurately.

Genetic Engineering X Immunology

Another new approach combines genetic engineering with the knowledge about the immune system to produce, or ‘engineer’, antibodies or fragments of antibodies that can bind to and alter the disease characteristics of certain proteins involved in several neurological disorders. These therapies can be delivered either as proteins or as genes.

Results So Far

Promising preliminary results have been provided for a myriad of conditions, such as Huntington’s disease, Parkinson’s disease, Alzheimer’s disease and prion disease among others. An example of such promising research, is a study that fruit flies (Drosophila melanogaster, the favorite test animal of many geneticists, since the genome of this species is entirely known) that get Huntington’s disease because they have been modified to carry the mutant human gene are generally too weak and uncoordinated to break out of their pupal case the way most insects do. However, when they also express the gene for the anti-HD antibody, all of them can emerge as young adults. Furthermore these treated flies lived significantly longer than the untreated ones that do manage to emerge, and the treated ones showed clearly less abnormalities in their brains.

It might seem that ‘these are just flies’, but research has shown that about 75% of human disease genes have some sort of analog or recognizable match in the genetic code of fruit flies. Furthermore, about half of the fly protein sequences have mammalian analogues. So there are good reasons to use this little fly as a genetic model for several human diseases. Drosophila is also being used to study the effects of aging and oxidative stress, diabetes, cancer and even drug abuse.

Sources

• Reiter, L.T.; Potocki, L.; Chien, S.; Gribskov, M. & Bier, E. (2001). "A systematic analysis of human disease-associated gene sequences in Drosophila melanogaster". Genome Research 11 (6): 1114–1125.
• Brain Facts: A Primer on the Brain and the Nervous System. Society for Neuroscience.