Behind the epidemic without previous Ebola in West Africa is a species with an incredible power to exceed its host. Zaire ebolavirus and the filovirus family to which it belongs must virulence mechanisms that first disarm the immune response and then dismantle the vascular system. The virus progresses so rapidly that researchers are struggling to unravel the precise sequence of events, especially in the midst of an epidemic. Much is still unknown, including the role of some of the seven proteins that the virus RNA, AOS is diverting the machinery of host cells and the type of immune response needed to defeat the virus before it spreads throughout the body. But researchers can test how different live virus attacks cells in culture and can observe the progression of disease, AOS in primates, AIA nonhuman model almost identical to humans.
Here are some basic things that we understand how Ebola and humans interact.
What do the Ebola virus for the immune system?
Once the virus enters the body, it has several types of immune cells that are the first line of defense against invasion. The virus infects dendritic cells, which normally have signals of an infection on their surfaces to activate lymphocytes, Äîthe T white blood cells that can destroy other infected cells before the virus replicates further. With defective dendritic cells not giving the right signal, the T cell donation, AOT respond to infection, and do the antibodies that depend on them for activation. The virus can begin replicating immediately and very quickly.
Ebola, like many viruses, works in part by inhibiting molecule type interferon, AIA that cells use to prevent further viral reproduction. In a new study published today in Cell Host & Microbe , the researchers found that one of the Ebola protein, AOS, called VP24 binds to and blocks a transport protein on the surface of immune cells that plays an important role in the pathway of interferon.
Curiously, themselves donation lymphocytes, AOT be infected, but a series of other lack factoring, AIA stimulation of certain cells and toxic to others signals Äîprevent these primary immune cells to a fight.
How Ebola cause of bleeding?
As the virus moves into the bloodstream to new sites, other immune cells called macrophages eat up. Once infected, they release proteins that trigger the coagulation, forming small clots through the blood vessels and reducing blood supply to the organs. They also produce other inflammatory signaling proteins and nitric oxide, which damage the wall of blood vessels, causing a leak. Although this damage is one of the main symptoms of infection, all patients will exhibit hemorrhaging, external Äîbleeding eyes, nose or other orifices.
Does the target of some of the organs virus?
Ebola triggers inflammation and system fever and can also damage many types of tissue in the body, either by tricking the immune cells such as macrophages to release inflammatory molecules or by direct injury : invade cells and consume in. But the consequences are particularly deep in the liver, where Ebola erases cells necessary to produce coagulation proteins and other important components of plasma. Damaged cells in the gastrointestinal tract lead to diarrhea which often puts patients at risk of dehydration. And in the adrenal gland, the virus paralyzes the cells that make steroids to regulate blood pressure and causes circulatory failure that can starve the oxygen of organs.
What finally kills Ebola patients?
damage to the blood vessels leads to a drop in blood pressure, and patients die of shock and multiple organ failure.
Why do some people survive infection?
patients fare better with supportive care, including rehydration orally or intravenously that can buy time for the body to fight infection. But studies on blood samples from patients during the outbreak in 00 of a different Ebola strain in Uganda have also identified genes and other markers that seem to be a predictor of survival. Patients who have recovered higher levels of activated T cells in the blood, and there was some variants of a gene coding for surface proteins as white blood cells use to communicate. Earlier this year, researchers found a new association between survival and levels of sCD40L, a protein produced by platelets that could form part of the body attempt, AOS to repair damaged blood vessels. The authors note that the markers as sCD40L could suggest new therapies that increase the most important mechanisms for the repair of survival
* Correction, August 15, 1:51 p.m. :. This article has been corrected to note that nitric oxide, nitrous oxide does, damages blood vessels
* Ebola files :. Given the current Ebola epidemic, unprecedented in terms of the number of people killed and the rapid geographic spread, science and Science Translational Medicine made a collection of research articles and news on the viral disease available for researchers and the general public.
0 Komentar