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[Date: 2005-09-09]

A research team at the Institute of Parasitology and Biomedicine of the Spanish National Research Council (CSIC), in Grenade, has successfully developed in mice a cellular therapy for two major autoimmune diseases: rheumatoid arthritis and multiple sclerosis. The scientists succeeded, in both experimental models, in making the symptoms disappear and inducing a reversion of the degenerative process. The results of the research were published this week in the digital edition of the Proceedings of the National Academy of Sciences (PNAS).

Autoimmune diseases occur when the immune system that normally protects the body from disease and infection attacks itself. Autoimmune diseases can affect many parts of the organism, like the nerves or the muscles, and cause significant and chronic morbidity and disability.

The therapy uses a certain type of cells (dendritic cells), which when injected in animals affected by these disorders, generate T regulating (Tr) cells, responsible for the maintenance of immune tolerance. CSIC scientist and lead of the research team, Mario Delgado, explains: 'the analysis of the cellular mechanisms has unveiled that these dendritic cells induce new Tr cells in the treated animals, and that these cells specifically neutralise the immune cells that attack components of the joint, in the case of rheumatoid arthritis, or the myelin covering the nerves, in the case of multiple sclerosis'.

The therapy was also effective with Tr cells generated in vitro. In both cases, the response was induced by using a known immunosuppressive neuropeptide, the vasoactive intestinal peptide (VIP), a protein that is produced by lymphoid as well as neural cells, that the scientists know acts like a powerful anti-inflammatory agent. The research team lead by Dr Delgado has studied the use of the VIP on a multiple sclerosis model for ten years.

The therapeutic process would start by extracting blood or marrow cells from the patient suffering the autoimmune disorder. These cells would be treated with VIP so that they turn into dendritic cells. Finally, these cells could be injected in the patient so that they induce new Tr cells and the immunological tolerance is recovered. An alternative therapy could be based on using these regulating dendritic cells in vitro to generate the Tr cells that could be then injected into the patient.

Dr Delgado, explains that 'the results with animals are very promising', although, he is cautious about its eventual use in humans, warning that this would be a 'customized personal cellular therapy implying high costs'. Its use could be justified though as some degenerative disorders do not have any alternative effective treatment. Multiple Sclerosis (MS) is a chronic and severe neurological disease, largely diffused all over the world. MS preferentially affects young adults and has high social costs, representing a real emergence at both clinical and social levels.

To download the abstract of the PNAS paper, please consult the following web address:
http://www.pnas.org/cgi/content/abstract/0504484102v1