Sunday, November 2, 2014

Genes Could be Influential For Surviving From Ebola

When some people are exposed to Ebola, some resist the disease, others suffer moderate to severe illness and recover, and some who are most vulnerable succumb to bleeding, organ failure, and shock. There is not necessarily a change to the Ebola virus itself but how a person’s body attempts to fight the infection which determines the severity of the disease. On October 30, 2014 Angela Rasmussen and Michael Katze described strains of laboratory mice bred to test the role of an individual’s genetic makeup in the course of Ebola disease. This study was hindered by the lack of a mouse model that replicates the main characteristics of human Ebola hemorrhagic fever. Angela Rasmussen and Michael Katze originally obtained this genetically diverse group of inbred laboratory mice to study locations on mouse genomes associated with influenza severity.

These scientists infected mice with the same species of Ebola virus causing the 2014 West Africa outbreak. Initially, conventional laboratory mice that were previously infected with this virus died and didn’t develop symptoms of Ebola hemorrhagic fever. The present study, all the mice lost weight in the first few days after infection. Nineteen percent of the mice were unfazed; they survived and fully regained the weight they lost within two weeks. They didn’t experience gross pathological evidence of disease while their livers looked normal. Eleven percent of the mice were partially resistant and less than half of them died. Seventy percent of the mice had greater than 50 percent mortality while 19 percent had liver inflammation without classic symptoms of Ebola and 34 percent had blood that took too long to clot which is a hallmark of fatal Ebola hemorrhagic fever in humans.  The mice with Ebola hemorrhagic fever also had internal bleeding, swollen spleens, and changes in liver color and texture. The scientist correlated disease outcomes and variations in mortality rates to specific genetic lines of mice.
The data suggested that genetic factors play a significant role in disease outcome. When the virus infection frenzies the genes involved in promoting blood vessel inflammation and cell death, serious or fatal disease followed. On the other hand, survivors experienced more activity in genes that order blood vessel repair and the production of infection-fighting white blood cells. Rasmussen and Katze also noted that certain specialized types of cells in the liver could also have limited virus reproduction and put a damper on systemic inflammation and blood clotting problems in resistant mice. Vulnerable mice had widespread liver infection, which may have explained why they had more virus in their bodies and poorly regulated blood clotting. Rasmussen and Katze also noticed that soleens in the resistant and vulnerable mice took alternate routes to try to ward off infection.

This mouse model has the potential to be promptly implemented to find genetic markers, conduct meticulous studies on how symptoms originated and take hold, and evaluate drugs that have broad spectrum anti-viral activities against all Zaire Ebola viruses, including the one responsible for the current West African epidemic.

Although this is a new study and innovating, we don’t truly know if a person’s genes are what influence life or death due to this virus. I guess one way to further study if genes do have a role in survival is to test on humans but who would actually put themselves in harms ways.
Article: http://www.sciencedaily.com/releases/2014/10/141030142206.htm

1 comment:

  1. The article I posted was very similar to the article you posted. I found it as a great achievement how the scientists figured out that the genetic make-up of the mice was correlated to the severity of the Ebola virus. I wonder how much progress will be made with the mice? What genes specifically do they need? A lot of questions arise through this experiment.

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