Scientists discover new cell type in the immune system

Jun 16 2011

A team of Australian 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.

Their 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 in the international journal Nature Immunology, is 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 recognise 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 have identified a new type of NKT cell that can specifically target lipids found in the cell walls of bacteria, including Mycobacteria.

Professor Dale Godfrey from the University of Melbourne said the discovery is significant and opens the door to a new avenue of investigation into immunity.

"The identification of a new cell type paves the way for many new studies into the unique function of these cells and how they might be harnessed for the development of new types of vaccines," he said.

Using the Australian Synchrotron, the team produced a molecular image of precisely how the new cell type's T-cell receptor recognises lipid-based molecules.

"The use of the Australian synchrotron was essential for us to undertake our study," Dr Onisha Patel from Monash University said.

Source: University of Melbourne