Tonsils make T-Cells, too

A new study provides evidence that a critical type of immune cell can develop in human tonsils. The cells, called T lymphocytes, or T cells, have been thought to develop only in the thymus, an organ of the immune system that sits on the heart. The study, led by researchers at The Ohio State University, could improve the understanding of T-cell cancers and autoimmune diseases, and how stem-cell transplantation is done. The study identified T cells at five distinct stages of development in the tonsil. These stages, identified using molecular signposts on the cells, were very similar to the stages of T-cell development in the thymus, although some differences were found as well. The study also discovered that the cells develop in a particular region of the tonsil.