Scientists at OMRF have discovered a mechanism that allows white blood cells to find and fight disease-causing microorganisms. The findings could have important implications for treating leukemia and autoimmune diseases such as lupus.
OMRF researchers Lijun Xia, M.D., Ph.D., and Rodger McEver, M.D., have determined how sugars in white blood cells interact with a cell adhesion molecule known as E-selectin in blood vessels to direct the immune system to the site of infection by a pathogen. They’ve published their findings in the Proceedings of the National Academy of Sciences.
“White blood cells are like police on patrol in the blood stream,” said Xia. “When there’s a problem in the tissue, E-selectin in the blood vessels acts like an alarm.”
As white blood cells circulate in the bloodstream, the E-selectin reaches out and catches the sugar on the outside of the cells, like Velcro. The cells slow and then are able to enter the tissue, where they go to work fighting infection.
“That part of the immune system is important for fighting disease, but it can also go awry,” said McEver, who holds the Alvin Chang Chair in Cardiovascular Biology at OMRF. “Sometimes the inflammation caused by the white blood cells is like a riot, calling in more and more police and making things worse. Other times, the white blood cells might not get the signal or send too few officers to manage the problem.”
Discovering how the immune system and blood vessels interact, said Xia, could help physicians control the process. By halting or regulating the coupling, doctors could reduce the numbers of white blood cells that enter the tissue.
According to Xia, this could have a multitude of potential therapeutic applications, including controlling seizures in conditions such as epilepsy and managing autoimmune diseases like lupus and Crohn’s disease. “And in situations where more white blood cells are needed, such as in bone marrow transplants for leukemia, the interaction could be stimulated to make sure the cells find their way to the right areas,” he said.
OMRF’s Tadayuki Yago, M.D., Ph.D., also contributed to the research, which was funded by a grant from the National Heart, Lung and Blood Institute.