MAR 14, 2016 02:52 PM PDT

Defining the Role of Tumor Necrosis Factor During Chronic Viral Infections

WRITTEN BY: Kara Marker
Some viral infections, like HIV, are chronic, while others are acute. HIV infections are labeled chronic because the virus targets and kills helper T cells, and without these lymphocytes the body cannot fight off the HIV infection. Viruses causing acute infections, like the seasonal “stomach bug,” work differently and can be eliminated by the body.

New research from a collaboration between the University of Bonn, University of Cologne, and the Technical University of Munich has led to the discovery of an explanation for why certain viral infections are chronic and others are not. This same discovery has promise for generating new therapeutic targets.
 
Helper T cells secrete inflammatory messengers, a kind of “distress call” to killer T cells to come to their aid and fight off invading pathogens. However, viruses that cause a chronic infection, like HIV, employ virulence factors to silence these messages, ironically rendering the helper T cells helpless and ineffective.
 
In the recent collaborative study, published in the journal Nature Immunology, scientists studied mice models of chronic viral infection to see which helper T cell genes remain active when silenced by viruses. They were able to implicate tumor necrosis factor (TNF) as an agent of chronic viral infection. TNF controls various signaling pathways that inhibit helper T cell activity during chronic inflammation. In mice suffering from HIV-esque chronic viral infections with TNF inactivated, helper T cells produce inflammatory messengers like normal.
 
TNF plays a role in several different functions.

 
“After ten days, the animals had completely eliminated the virus; they were healthy,” explained Dr. Marc Beyer from the University of Bonn.
 
Meanwhile, during acute viral infections, TNF has the opposite effect. It boosts the immune system and stimulates apoptosis in cells corrupted by viral particles.
 
“In an acute infection, large quantities of TNF are formed very rapidly," said Dr. Zeinab Abdullah from the University of Bonn. "In chronic infections, on the other hand, the body secretes small amounts of TNF over a long period of time. This appears to cause the helper T cells to shut down to some extent."
 
The difference seems to stem from some sort of protective mechanism that prevents healthy tissues from being damaged from persistent inflammation, however the team is still in the dark about how exactly TNF works on a molecular level. For the time being, TNF inhibitors could be useful as a therapeutic treatment for patients with chronic viral infections like they are currently used for patients with rheumatoid arthritis and other autoimmune diseases.
 
 
Source: University of Bonn
 
About the Author
  • I am a scientific journalist and enthusiast, especially in the realm of biomedicine. I am passionate about conveying the truth in scientific phenomena and subsequently improving health and public awareness. Sometimes scientific research needs a translator to effectively communicate the scientific jargon present in significant findings. I plan to be that translating communicator, and I hope to decrease the spread of misrepresented scientific phenomena! Check out my science blog: ScienceKara.com.
You May Also Like
NOV 13, 2019
Health & Medicine
NOV 13, 2019
A Second Patient Cured of HIV: Are We Close to a Cure for Everyone Infected?
There is a consensus that the first HIV infection occurred in the 1920s in Kinshasa, the Democratic Republic of Congo when it was passed to human...
NOV 13, 2019
Drug Discovery & Development
NOV 13, 2019
PARP Inhibitors Boost Immune Efficacy
In a recent research study, precision cancer drugs called PARP inhibitors are previously known to boost the immune system were found to spark a powerful im...
NOV 13, 2019
Health & Medicine
NOV 13, 2019
Fourth-Generation Rapid Diagnostic Tests for Acute HIV-1 Infections
The ability to diagnose an acute HIV-1 infection before there are detectable antibodies to HIV 1/2 is critical to making an early diagnosis and getting the...
NOV 13, 2019
Drug Discovery & Development
NOV 13, 2019
Novel Treatments for Auto-immune Disorders
A recent research study examined a library of almost 300,000 small molecules to search for a molecule that may be a potential target for the human GMP-AMP ...
NOV 13, 2019
Drug Discovery & Development
NOV 13, 2019
AI Exponentially Accelerates Drug Development
Research and development for new drugs is both an expensive and lengthy process, often lasting years, if not decades. With the development of artificial in...
NOV 13, 2019
Cell & Molecular Biology
NOV 13, 2019
New RNA Observation Shows Previously Unkown Attachment to Sugar
Scientists in the Bertozzi at Staford University have published surprising observations of glycan sugars attached directly to RNA during glycosylation.&nbs...
Loading Comments...