"The decisive factor that leads to hematopoiesis at otherwise dormant sites is the ability of NK cells to find and destroy virus-infected cells," says Jordan. Extramedullary hematopoiesis is actually initiated by the inflammatory reaction that occurs as an early response to infection with CMV. But when the virus can replicate and spread to other cells, the pathogen suppresses the process. "The development of extramedullary hematopoiesis in the spleen is dependent on the capacity of NK cells to prevent virus spread by effectively eliminating infected cells," Jordan explains.
Extramedullary hematopoiesis itself thus appears to be an antiviral reaction. This in turn has obvious implications for the development of novel therapies. Thus, targeted stimulation of the mechanism that triggers the process could help to fight and resolve viral infections. Conversely, there are situations in which the immune system overshoots, and the spleen becomes so enlarged that it has to be surgically removed. "In this context, it would be particularly useful to understand how CMV suppresses extramedullary hematopoiesis then one might be able to exploit the mechanism to prevent rupture of the splenic capsule and life-threatening internal bleedings," Jordan concludes.
|Contact: Luise Dirscherl|