Promising T cell therapy

PUBLIC RELEASE DATE:

17-Jun-2014

Contact: Vera Siegler vera.siegler@tum.de 49-892-892-2731 Technische Universitaet Muenchen

This news release is available in German.

The cells of the human immune system are created from special stem cells in the bone marrow. In diseases affecting the bone marrow, such as leukemia, the degenerate cells must be destroyed using radiation or chemotherapy. Subsequently, the hematopoietic system has to be replaced with stem cells from the blood of a healthy donor. Because of the resulting temporary weakening of the immune system, patients are more exposed to viruses that would normally be warded off.

The cytomegalovirus (CMV), which can cause serious damage to lungs or liver in persons with a weakened defense, poses a major clinical problem. In healthy human beings, a CMV infection will usually not produce any symptoms, since the virus is kept at bay by specific immune cells. In their work, the scientists were able to demonstrate that the transfer of just a few specific immune cells is sufficient to protect the recipient with the weakened immune system against infections. To do this, they used T cells that can recognize and kill specific pathogens.

Tested in an animal model

Dr. Christian Stemberger, first author of the study, and his colleagues, first isolated T cells from the blood of healthy donor mice. These immune cells were directed against molecular elements of a bacterial species which normally causes severe infections in animals. The T cells were then transferred to recipient mice that, due to a genetic modification, could no longer produce immune cells of their own similarly to patients suffering from leukemia.

Following the T cell transfer, the researchers infected the treated recipient mice with the bacteria. The results showed that the animals now have effective immune protection against the pathogens, preventing them from becoming ill. "The most astonishing result was that the offspring cells of just one transferred donor cell were enough to completely protect the animals," Christian Stemberger explains.

Successfully used in patients

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Promising T cell therapy