November 6, 2003
Boston Cure Project
Because it uses the body's own cellular machinery to manufacture therapeutic proteins, gene therapy has the potential to benefit a large number of diseases including MS. One issue to address in developing a gene therapy is how to get the modified genes to the sites where they are needed. One team of researchers has now created a technique for targeting gene therapy to sites of autoimmune activity and has demonstrated that it works in animals. 
In this study, the researchers used mice from three different autoimmune disease models, including EAE, and extracted T cells and dendritic cells from the mice. They selected cells that reacted to a specific autoantigen (MBP in the case of EAE) and exposed them to a retrovirus containing genes for regulatory cytokines and for a luminescence protein. Retroviral insertion of these genes into the DNA of the cells caused the cells to start producing the new proteins. The cells were then re-injected into the mice. Because these cells were luminescent (i.e., they transmitted photons through the tissue), the researchers were able to use a sensitive detector to determine where in the animals' bodies the cells had gone. They found that within a few days, the altered cells had migrated specifically to the target sites of inflammation where the autoantigens were found (the brain in the case of the EAE mice).
There are still many challenges to address in the development of gene therapies for diseases like MS, but the ability to put genes where we want them rather than indiscriminately throughout the body is an important achievement. It's also neat that this technique uses a feature of MS (namely, the inflammation which attracts certain cells) to carry out the targeting.
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