New Type of Immune T-Cell Discovered

A team of Melbourne scientists has discovered a new type of cell in the immune system. The new cell type, a kind of white blood cell, belongs to a family of T-cells that play a critical role in protection against infectious disease. The team’s findings could ultimately lead to the development of novel drugs that strengthen the immune response against particular types of infectious organisms. It is also potentially significant for many other important diseases including allergies, cancer, and coronary artery disease. The research team includes Dr Adam Uldrich and Professor Dale Godfrey from the University of Melbourne, Dr Onisha Patel and Professor Jamie Rossjohn from Monash University and Professor Mark Smyth from the Peter MacCallum Cancer Institute. The discovery, published online on June 12, 2011, in the international journal Nature Immunology, represents a fundamental advance in understanding the different components of the immune system and how this system casts a net wide enough to catch all kinds of different infectious organisms. Typically, when the body is threatened with bacterial or viral infection, molecules called T-cell receptors interact with protein fragments (called peptides) from the bacterium or virus, triggering the immune response. This process has been widely studied and leads to the killing of microbes and protection against severe infection. While the immune system is known to focus on proteins from viruses and bacteria, some T-cells in the immune system (known as NKT cells) can recognize lipid-based, or fatty, molecules. As such, there is great enthusiasm for the potential of these lipid-sensing T-cells in the development of novel vaccines. This team has identified a new type of NKT cell that can specifically target lipids found in the cell walls of bacteria, including Mycobacteria.