The immune system defends us against aggressions from outside (e.g. infections) and inside (e.g. cancer). To do so, it uses a very large variety of mechanisms that are ensured by many different cell-types and molecules. These mechanisms need to be carefully controlled to avoid immune-pathology; excessive immune-responses can lead to chronic inflammation, autoimmune diseases such as type I diabetes, and even spontaneous abortion. To avoid this, regulatory mechanisms control innate and adaptive immunity. One of the most important mechanisms depends on regulatory T lymphocytes expressing the transcription factor Foxp3. Absence of these cells leads to a very severe autoimmune syndrome. More subtle defects in these cells may be involved in diseases mediated by the immune-system. On the other hand, their unwanted activity can hinder development of immune-responses to cancer and thus hamper the eradication of tumors. Understanding the biology of regulatory T cells is therefore of paramount importance in the search for potential defects in pathology.
Regulatory T lymphocytes in transplantation
Transplantation is often the only therapeutic solution for severe dysfunction of tissues and organs. One of the major problems in transplantation-medicine is rejection of donor-tissue by the patient’s immune-system. Immunosuppressive medicaments can delay rejection, but they rarely entirely prevent it. They also have severe side effects, which in large part is due to their global immunosuppressive activity. Thus, patients develop opportunistic infections and have an increased incidence of cancer. Scientists therefore develop innovative therapies that efficiently suppress immunity to the donor tissue and do not block useful immune-responses. Given their central role in the control of immunity, regulatory T lymphocytes have the potential to do so. Recent evidence has confirmed the therapeutic potential of regulatory T lymphocytes in transplantation in experimental models and, increasingly, in clinical trials.
This symposium
In this symposium, several French and European experts will gather to present and discuss their latest results on the biology of regulatory T cells and on their use to prevent unwanted immune responses in transplantation.
