APCOM

Hemorrhagic fevers such as Ebola, Marburg and Lassa are made more aggressive by a particular protein of our immune system called alpha interferon. The discovery was made by the researchers of the Scientific Institute of the San Raffaele University, in collaboration with the Scripps Research Institute of La Jolla in California. The findings are published on the prestigious international scientific magazine "Proceedings of the national Academy of Sciences". According to the research it is our own virus defense system that sets off the hemorrhages typical of these diseases which can, in some cases, lead to the patient's death. That the production of alpha interferon was higher in those people affected by viral hemorrhagic fevers was already known. But the reasons underlying such mechanism were obscure and have been explained thanks to the findings of experiments conducted on mice infected by arenavirus, that together with the filoviridae, causes hemorrhagic fevers.

Results show that the alpha interferon weakens the defense system preventing it from cleaning up the organism from the viruses. The mice used in the experiment were genetically modified so that their cells could not ligate interferon: they did not develop hemorrhagic fevers despite the presence of the virus in their organism. This is because the cells of the bone marrow hadn't inhibited the production of platelets which worked properly as the interferon had not modified their functions.

The overproduction of interferon reduces the number and the functions of the platelets, not only causing dangerous hemorrhages but also inhibiting the immune response of the cells: a mechanism that depends on the good functioning of the platelets and is responsible for the elimination of the virus.

A somewhat bizarre situation from a virological point of view; alpha interferon is in fact vital antiviral molecule that plays a fundamental role: when attacked by a virus it informs the other molecules of the danger allowing them to prepare their defense mechanism.