Nav: Home

Scientists gain better understanding of how Ebola disables people's immune defenses

May 23, 2017

GALVESTON, Texas - University of Texas Medical Branch at Galveston scientists have unlocked mysteries of how the Ebola virus hampers the body's natural defenses to speed the rate of infection and its accompanying lethal disease, according to a new report in PLOS Pathogens. The study was conducted in collaboration with the University of Washington and The National Institute of Allergy and Infectious Diseases.

Specifically, the researchers found that the Ebola virus binds directly to white blood cells (critical to the immune system) leading to their death.

"There are experimental Ebola vaccines and therapies being tested in clinical trials, but none have received final approval yet," said senior author Alexander Bukreyev, a UTMB virologist in the departments of pathology and microbiology & immunology. "Understanding how the invading Ebola virus shuts down the host's immune systems is a very important step in developing targeted therapies for Ebola virus disease."

When someone is infected with Ebola, his or her lymphocytes - a type of white blood cell that is an important part of the immune system - quickly disappear. This issue is often seen in patients who succumb to the disease, whereas people who survive have been shown to maintain lymphocyte levels throughout the course of the disease.

The Ebola virus is not able to directly infect these white blood cells but yet they still die. It was known previously that the virus does affect cells and pathways that are critical to the well-being of lymphocytes, including a certain signaling pathway following binding to a receptor called TLR4. The goal of this study was to learn whether Ebola somehow directly impacts the lymphocytes and the role of TLR4 in lymphocyte cell death during an Ebola infection.

The researchers showed for the first time that despite the inability of Ebola to infect lymphocytes, it directly binds to them and causes cell death. The binding does involve the TLR4 pathway, among others. When Ebola virus binds to lymphocytes, TLR4 pathways activate cells and contribute to the death of lymphocytes, leaving the person more vulnerable to viral invasion.

"Adding a chemical that blocks TLR4 activation protected the lymphocytes in the presence of Ebola, confirming its role in infection and spread of disease throughout the body," said Dr. Mathieu Iampietro, the co-lead author of the study.

"Our findings suggest that a drug that blocks TLR4 could be used to treat patients with Ebola and extends our earlier findings that the TLR4 receptor antagonist Eritoran protects against both Ebola and the closely related Marburg virus," said Patrick Younan, the other co-lead author of the study.

Bukreyev continued that the study highlights the diverse strategies used by Ebola to cause lymphocytes to die through both direct and indirect methods, despite lack of infection.
-end-
Other authors include UTMB's Ndongala Michel Lubaki and Rodrigo Santos; Andrew Nishida, Mukta Dutta and Michael Katze from the University of Washington in Seattle and Richard Koup from The National Institute of Allergy and Infectious Diseases.

University of Texas Medical Branch at Galveston

Related Immune System Articles:

Memory training for the immune system
The immune system will memorize the pathogen after an infection and can therefore react promptly after reinfection with the same pathogen.
Immune system may have another job -- combatting depression
An inflammatory autoimmune response within the central nervous system similar to one linked to neurodegenerative diseases such as multiple sclerosis (MS) has also been found in the spinal fluid of healthy people, according to a new Yale-led study comparing immune system cells in the spinal fluid of MS patients and healthy subjects.
COVID-19: Immune system derails
Contrary to what has been generally assumed so far, a severe course of COVID-19 does not solely result in a strong immune reaction - rather, the immune response is caught in a continuous loop of activation and inhibition.
Immune cell steroids help tumours suppress the immune system, offering new drug targets
Tumours found to evade the immune system by telling immune cells to produce immunosuppressive steroids.
Immune system -- Knocked off balance
Instead of protecting us, the immune system can sometimes go awry, as in the case of autoimmune diseases and allergies.
Too much salt weakens the immune system
A high-salt diet is not only bad for one's blood pressure, but also for the immune system.
Parkinson's and the immune system
Mutations in the Parkin gene are a common cause of hereditary forms of Parkinson's disease.
How an immune system regulator shifts the balance of immune cells
Researchers have provided new insight on the role of cyclic AMP (cAMP) in regulating the immune response.
Immune system upgrade
Theoretically, our immune system could detect and kill cancer cells.
Using the immune system as a defence against cancer
Research published today in the British Journal of Cancer has found that a naturally occurring molecule and a component of the immune system that can successfully target and kill cancer cells, can also encourage immunity against cancer resurgence.
More Immune System News and Immune System Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: The Power Of Spaces
How do spaces shape the human experience? In what ways do our rooms, homes, and buildings give us meaning and purpose? This hour, TED speakers explore the power of the spaces we make and inhabit. Guests include architect Michael Murphy, musician David Byrne, artist Es Devlin, and architect Siamak Hariri.
Now Playing: Science for the People

#576 Science Communication in Creative Places
When you think of science communication, you might think of TED talks or museum talks or video talks, or... people giving lectures. It's a lot of people talking. But there's more to sci comm than that. This week host Bethany Brookshire talks to three people who have looked at science communication in places you might not expect it. We'll speak with Mauna Dasari, a graduate student at Notre Dame, about making mammals into a March Madness match. We'll talk with Sarah Garner, director of the Pathologists Assistant Program at Tulane University School of Medicine, who takes pathology instruction out of...
Now Playing: Radiolab

What If?
There's plenty of speculation about what Donald Trump might do in the wake of the election. Would he dispute the results if he loses? Would he simply refuse to leave office, or even try to use the military to maintain control? Last summer, Rosa Brooks got together a team of experts and political operatives from both sides of the aisle to ask a slightly different question. Rather than arguing about whether he'd do those things, they dug into what exactly would happen if he did. Part war game part choose your own adventure, Rosa's Transition Integrity Project doesn't give us any predictions, and it isn't a referendum on Trump. Instead, it's a deeply illuminating stress test on our laws, our institutions, and on the commitment to democracy written into the constitution. This episode was reported by Bethel Habte, with help from Tracie Hunte, and produced by Bethel Habte. Jeremy Bloom provided original music. Support Radiolab by becoming a member today at Radiolab.org/donate.     You can read The Transition Integrity Project's report here.