Severing the spinal cord causes complete paralysis of the organs innervated by the central nervous system, from the point of injury downwards. In fact, even a partial injury of the spinal cord may cause complete paralysis. The main reason for this is that damaged fibers create a 'hostile environment' which harms other, undamaged fibers. As a result, even in cases of partial spinal cord injury, the damage continues to spread, intensifying the paralysis. Blocking the spread of damage may therefore save the nerve cells undamaged by the initial trauma, and with them - at least some of the patient's motor activity. This is what the Weizmann Institute scientists hope to achieve.
Several years ago, a team of researchers led by Prof. Michal Schwartz of the Weizmann Institute's Neurobiology Department found that following neuronal injury, immune cells known as macrophages may be 'recruited' to encourage repair and renewed growth of damaged nerve fibers.
Profs. Schwartz and Irun R. Cohen of the Immunology Department now hope to take this research one step further. They propose adding additional immune cells, known as T-cells, to the damage-control battalion aimed at blocking the spread of spinal cord damage.
At first glance, this idea seems to oppose the widespread view of immune cells as potentially damaging to the central nervous system (brain and spinal cord). However, this revolutionary treatment has already been successfully tested on laboratory animals, as described by the researchers in their article appearing in the current issue of the medical journal The Lancet.
T-cells function to prevent infection by seeking out and destroying pathogenic 'enemies' that infiltrate the body. But the body may also possess T-cells that are directed against its own components. The accepted notion is that such anti-self T-cells are harmful factors that may cause autoimmune diseases, such as multiple sclerosis and diabetes. However, the Institute scientists have now shown that a controlled amount of these autoimmune cells, when directed against specific neuronal components, can assist in curbing injury-induced neuronal damage.
Following treatment with anti-self T-cells, rats with partial injuries of the spinal cord regained some motor activity in their previously paralyzed legs, while untreated rats developed increasing paralysis, and sometimes even total paralysis. These findings may lead to an innovative clinical treatment for preventing total paralysis after partial spinal cord injury. This treatment will be based on extracting immune cells from the patient's blood, increasing their amount, and then re-introducing them into the damaged neuronal area. 'The concept is to work together with the body's existing self repair mechanism, which apparently requires encouragement and monitoring,' explains Prof. Michal Schwartz.
The scientists participating in this study were Ehud Hauben, Uri Nevo, Eti Yoles, Gila Moalem, and Eugenia Agranov, in collaboration with Prof. Michal Neeman from the Weizmann Institute and Prof. Solang Akselrod from Tel Aviv University.
The study was funded by Proneuron Ltd.
Prof. Michal Schwartz holds the Maurice and Ilse Katz Chair of Neuroimmunology. Prof. Irun Cohen holds the Helen and Morris Mauerberger Chair in Immunology.
The Weizmann Institute of Science is a major scientific research graduate study located in Rehovot, Israel. Its 2,500 scientists, students and support staff are engaged in more than 1,000 research projects across the spectrum of contemporary science.