Scientists established a comprehensive protein interactions map of the replication machinery of a chronic virus

December 20, 2017, CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences
Schematic illustration of an LCMV-Infection and the interactions of the LCMV polymerase (in violett) with cellular proteins. Credit: CeMM/Bojan Vilagos

Chronic viral infections like HIV or hepatitis are among the biggest threats to human health worldwide. While an acute viral infection usually results in full recovery and effective immune memory, chronic viruses evade the immune system and remain permanently in the host's body. Treating such viruses is a difficult task, as the molecular events during the development of a chronic infection remain largely elusive.

With their latest study published in PLOS Pathogens, the team of Andreas Bergthaler at the Austrian Academy of Sciences, in cooperation with the University of Basel and the MRC Laboratory of Molecular Biology, Cambridge, made an important contribution to the understanding of chronic viral infections. The scientists established the first comprehensive overview of cellular proteins interacting with the LCMV polymerase, a crucial enzyme for the replication of the and for chronic infection. By mapping them in the , they revealed viral strategies and potential targets for future antiviral therapeutics.

In order to perform the study, the researchers, including Ph.D. student Kseniya Khamina as first author, developed a novel approach to tag . The interactions of the LCMV polymerase with the proteins of the host cells were determined. Combined with publicly available data from other RNA viruses' polymerase interactomes, the generated dataset allowed the researchers to map the cellular pathways targeted by different viral polymerases. Some of the proteins found to interact with the LCMV polymerase turned out to be essential for the viral life cycle.

Simplified depiction of LCMV and human influenza and hepatitis C interactomes (shared. interactions highlighted in red). Credit: CeMM/Bojan Vilagos
"With our newly developed method we were able to show that some proteins, like DDX3X, have a proviral effect—they are important binding partners for the virus to survive. Others, like the TRIM21 protein, show more of an antiviral effect, they serve the host cell as an intracellular defense against the pathogen," explains Kseniya Khamina. "Mice lacking the TRIM21 entirely showed an impaired virus control when infected with a chronic strain of LCMV."

"The results of our study provide the first comprehensive overview of the molecular binding partners of the LCMV polymerase. Furthermore, their mapping in the human proteome reveals important strategies of chronic viruses," Andreas Bergthaler summarizes the findings. "We hope that our research leads to a better understanding of the emergence of and the complex molecular interactions of viruses and their hosts, and that we can thereby contribute to the development of novel antiviral therapies."

Explore further: New therapeutic target against persistent viral infections

More information: "Characterization of host proteins interacting with the lymphocytic choriomeningitis virus L protein" PLOS Pathogens, December 20, 2017. DOI: 10.1371/journal.ppat.1006758

Related Stories

New therapeutic target against persistent viral infections

January 11, 2017
Life is a question of balance, and the body is no exception. Expression levels of certain proteins can affect the immune system's ability to neutralize a virus. Type I interferons (IFN-I) are cytokines that were previously ...

Hepatitis C virus: How viral proteins interact in human cells

May 8, 2014
Scientists at the Helmholtz Zentrum München have for the first time decrypted the interaction network of hepatitis C virus proteins in living human cells. Their findings will contribute to a better understanding of the mechanisms ...

Immune 'traffic jam' from viral infection interferes with therapeutic antibodies

February 12, 2015
Several drugs now used to treat cancer and autoimmune diseases are actually repurposed tools derived from the immune system. One of the ways these "therapeutic antibodies" work is to grab onto malignant or inflammatory cells ...

Scientists identify interferon beta as likely culprit in persistent viral infections

May 13, 2015
Interferon proteins are normally considered virus-fighters, but scientists at The Scripps Research Institute (TSRI) have found evidence that one of them, interferon beta (IFNβ), has an immune-suppressing effect that can ...

Study finds interferon, one of the body's proteins, induces persistent viral infection

April 11, 2013
Scientists at The Scripps Research Institute (TSRI) have made a counterintuitive finding that may lead to new ways to clear persistent infection that is the hallmark of such diseases as AIDS, hepatitis B and hepatitis C.

Recommended for you

Marker may help target treatments for Crohn's patients

October 16, 2018
Crohn's disease (CD), a chronic inflammatory condition of the intestinal tract, has emerged as a global disease, with rates steadily increasing over the last 50 years. Experts have long suspected that CD likely represents ...

Polio: Environmental monitoring will be key as world reaches global eradication

October 15, 2018
Robust environmental monitoring should be used as the world approaches global eradication of polio, say University of Michigan researchers who recently studied the epidemiology of the 2013 silent polio outbreak in Rahat, ...

Study traces hospital-acquired bloodstream infections to patients' own bodies

October 15, 2018
The most common source of a bloodstream infection acquired during a hospital stay is not a nurse's or doctor's dirty hands, or another patient's sneeze or visitor's cough, but the patient's own gut, Stanford University School ...

Researchers make essential imaging tests safer for people at risk of acute kidney injury

October 15, 2018
Every year, millions of people undergo medical tests and procedures, such as coronary angiography, which use intravascular contrast dyes. "For the majority of patients, these are safe and necessary procedures. However, about ...

Do not give decongestants to young children for common cold symptoms, say experts

October 11, 2018
Decongestants should not be given to children under 6—and given with caution in children under 12—as there is no evidence that they alleviate symptoms such as a blocked or runny nose, and their safety is unclear, say ...

New techniques can detect Lyme disease weeks before current tests

October 11, 2018
Researchers have developed techniques to detect Lyme disease bacteria weeks sooner than current tests, allowing patients to start treatment earlier.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.