Thursday, June 9, 2022

Epstein-Barr Virus: Not just a Kissing Disease

I'm sure you or someone you know has had mono in their lifetime. This saliva passed virus that can knock you out for a few months doesn't really end after that. Epstein-Barr Virus (EBV) is the disease that causes mononucleosis. This is one of the most common viruses across the globe, but it can have some pretty nasty long term effects. This tiny little virus is known to weaken your immune system but can do two other crazy things to mess with your body.

Epstein-Barr Virus Cell

First lets talk about the structure of EBV. The EBV virus is a linear viral cell composed of DNA with about 85 genes. EBV once it has entered the body goes after your B cells and epithelial cells. Even though EBV only enters these cells, the way they enter and replicate are different. To enter a B cell, a viral protein binds to a cell receptor which triggers the fusion of viral envelopes with the membrane of the B cell. To enter epithelial cells, a different viral protein interacts with a cellular integrin. The B-cell entry is not impeded directly by a viral protein, unlike the entry of EBV to an epithelial cell.

Epstein-Barr along with other forms of herpes does not go away after initial exposure. Once the virus is fought off it remains in your body in a dormant state. When your immune system is "distracted" fighting off another disease it is put under significant stress. EBV can take this opportunity to come out of hiding and attack your B cells. This activates the EBV in you allowing you to become contagious. You can shred the disease at age seventy-six even if you had it at seven years old.

Epstein-Barr Cell Structure

In addition to this virus never going away, it can become the cause of other illnesses. When you are infected with EBV the immune cells produce a protein by the name of EBNA2. Using transcription factors, these proteins bind to the genome of the cell and the virus. These new transcription factors adapt the expression of new viral genes as they enter the body making you more susceptible to these new viruses when they enter your body. These transcription factors can put you at an increased risk for diseases such as lupus and several other autoimmune diseases, including multiple sclerosis (MS), rheumatoid arthritis, inflammatory bowel disease, type 1 diabetes, juvenile idiopathic arthritis and celiac disease. When specifically talking about Lupus, they found that the protein EBNA2 could be used at the binding site to drive the activation of these disease. This is deemed problematic because of how common Epstein-Barr is to humans. 

In regards to MS, people believe that Epstein-Barr can be the underlying cause of the disease. They ran an active experiment to test when the donors in this experiment became infected with EBV.    They tested samples from 801 people who developed MS. They then compared these to samples from more than 1,500 matched controls. Out of the 801 MS cases only one did not show signs of EBV before the onset of MS occurred. While scientists cannot say this is the underlying cause of both MS and other diseases, they can determine that this is a contributor to other diseases. 


Vaccination

As of May 2022, they have announced they are starting the early clinical trials for a vaccine for Epstein-Barr. This study will include 40 young adults, each will receive three doses of the vaccination. This will last about four years with the intent being a reduction in severity and instances of EBV linkage with other autoimmune diseases.

Viruses tend to uproot our lives. I chose this topic because in the fall I had a very nasty cold. After several doctors appointments, and no solutions they figured it actually wasn't viral but rather bacterial. While sitting in the office, one of the things that I had symptoms for was mono. My doctor shared with me information about EBV dormancy and it really struck me. I found it so interesting that I could get EBV from someone who had the virus twenty years ago! After doing more research I think its crazy to see how detrimental this virus can be to those who get the worst of the worst effects and I am hopeful to see a successful vaccine in the future!

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