Understanding the Ebola Virus

Ebola was first recorded in the Democratic Republic of the Congo in 1976. Though the outbreaks are generally small, the severity, as well as death rates of as high as 90 percent,  makes the virus a big threat. The most recent outbreak started in December 2013. The virus is easily spread through bodily fluids and often results in deaths caused by dehydration and heavy bleeding. There is currently no cure to the Ebola virus and there are no FDA-approved vaccinations. However, identification and better understanding of the protein structure could lead to drugs or vaccines that could prevent infection.

Ebola is a member of the Filoviridae family of viruses, containing a linear, negative-sense single-stranded RNA. The negative sense means that it is complementary to the mRNA, so it has to be converted by the host cell in order to be replicated.  The Ebola virus structure, referred to as a virion, is approximately 80 nm in diameter and 800 nm long. Considering that the diameter of a human hair is about 75,000 nm, the impact that something so small can have on the human body is phenomenal. The virion has several different proteins with different roles in living cells, which viruses can replicate.

Most viruses, like the flu virus, bind to the cell then enter the cell. Once inside, the virus inserts its genome in the cell so it can reproduce more viral proteins and RNA, then it leaves the cell and repeats the process. This is essentially what the Ebola virus does with its surface protein, glycoprotein (GP). The glycoprotein on the surface of the protein is one of the proteins critical to the Ebola virus.  It was identified by scientists at The Scripps Research Institute. A glycoprotein is covalently attached to carbohydrate chains at its polypeptide side chains. This protein plays a role in the virus attaching to and entering a host cell, as well as protecting the virus from the immune system.  The glycoprotein is said to have two subunits referred to as GP1 and GP2. Each subunit has a different structure and function.

Each protein in the virus plays an important role in ensuring the successful invasion of a host cell. GP1 allows the virus to attach to the host cell by engaging receptors. GP2 is responsible for the fusing of the virus and host cell membranes. The other viral proteins mentioned earlier also play a role in creating this seemingly indestructible virus; some proteins create structural reinforcement, while others help with the replication process .

Once in the cell the Ebola is able to damage the cell. What sets Ebola apart from the flu virus, and makes it so deadly, is its ability to elude the body’s immune system. In order to defend itself from viral attacks the body has the interferon pathway (IFN), which allows it to prevent viral replication and take the necessary precaution to impede viral attacks. Protein in the Ebola inhibits the IFN pathway, which would normally activate the inactive interferon. Unfortunately, there is not a clear understanding of the mechanism that causes the inhibition.

Several studies have been conducted on the Ebola virus. With each new study a better visual of what the Ebola virion looks like is obtained. With continuous study of the virus a guide to creating necessary drugs or vaccine may be acquired. Research into Ebola also allows us to understand how the protein’s surface and entire structure can be deactivated by an antibody, preventing the virus from entering the host cell.