March 2015 Antenna-like structures found on immune cells for first time

A team of NUI Galway scientists have found that cells of the immune system have a previously undescribed ability. In a paper just published Journal of Cell Biology, the scientists describe the presence of primary cilia on immune cells. These antenna-like structures are found on almost all cell types in the body, but since the 1960s, it has been thought that they do not arise in blood cells.

Professor Ciaran Morrison of NUI Galway’s Centre for Chromosome Biology, who co-authored the paper with Dr Suzanna Prosser, explains the significance: “The paper is of scientific interest because it provides new information about how ciliation is controlled. Also, we have shown that immune cells do at least have all the material they would need to make primary cilia. The next question is whether the cells make cilia in the body.”

Cilia are structures that stick out of cells to sense their local environment. They are very important in monitoring fluid flows, so problems with cilia cause diseases that affect body orientation, development, the eye, the kidney and various other organs. These diseases, which include Joubert syndrome and polycystic kidney disease, are called ciliopathies.

The paper describes how a small calcium-binding protein called centrin controls primary cilium formation by removing an inhibitor of ciliation called CP110 from the base of the cilium, allowing it to extend. Professor Morrison and his team discovered this by using gene disruption techniques in cultured retinal cells and in cultured blood cells, where they also found that cell starvation can induce cilia.

Active immune system cells, including B- and T-lymphocytes, divide rapidly, so they would not normally have a chance to make cilia. “Cilia have not been described in lymphocytes before, to our knowledge”, explains Professor Morrison.

“We starved the cells of nutrients to delay their division cycle, but ciliation still occurred at a very low frequency, in about 5% of cells. It is possible that, even if cilia do exist in the body on certain slow or non-dividing blood cell populations, they may be short-lived, difficult to visualise or rare. What ciliated immune cells might do is an entirely new question. These results, which came from work funded by Science Foundation Ireland, illustrate how surprising findings can emerge from work on unrelated topics.”

The 60 scientists led by 11 Principal Investigators at the Centre for Chromosome Biology in NUI Galway are dedicated to understanding many different areas of chromosome biology, such as how cell proliferation is controlled, the structure and maintenance of the genome, precise control of genome duplication and how genes are expressed. Their work is critical to the ongoing scientific battle against cancer and other areas including human reproduction and fertility and genetic diseases such as Huntington’s Disease.

-ends-