Monash University scientists have rejuvenated the immune systems of mice and humans using a common hormone. The scientists, led by Associate Professor Richard Boyd and Dr Jayne Sutherland from the Monash Immunology and Stem Cell Laboratories, have revitalised the thymus which produces the T cells required to fight infection but which shuts down from early adulthood. Their achievement, published in the August issue of the Journal of Immunology, has offered new hope for patients with cancer, AIDS and other immunodeficiencies and for transplant patients. The Monash study showed inhibiting sex steroids through the Leuteinizing Hormone-Releasing Hormone could help regrow the thymus, increase output of new T cells, enhance T cell responses and improve recovery following bone marrow transplants. It also showed, for the first time, that prostate cancer patients who had their sex steroids temporarily blocked had increased levels of new T cells in their blood. The researchers found inhibiting sex steroids improved the production of haemopoietic stem cells in bone marrow. These cells provide ‘fuel’ for the bone marrow and thymus to produce blood cells. Associate Professor Boyd said the immune system deteriorated severely with age, and was further destroyed by severe viral infection and common cancer treatments such as chemotherapy and radiotherapy.
