But preventing white blood cells' circulation by trapping them in the lymph nodes can help mice get rid of a chronic viral infection, researchers at Yerkes National Primate Research Center and the Emory Vaccine Center have found.
Their findings, published this week in the journal Nature, suggest a new strategy for fighting chronic viral infections that could apply to the treatment of human diseases such as hepatitis C and HIV/AIDS.
The team's discoveries grew out of their study of two varieties of a virus that causes meningitis in mice, says senior author John Altman, PhD, associate professor of microbiology and immunology at Yerkes Research Center and Emory University School of Medicine.
The first author of the paper was postdoctoral fellow Mary Premenko-Lanier, PhD, with contributions from Sarah Pruett, PhD, assistant director of the Biomarkers Core Lab at Yerkes Research Center and graduate students Nelson Moseley and Pablo Romagnoli.
Standard black laboratory mice can fight off infection by the Armstrong strain of lymphocytic choriomeningitis virus (LCMV), but are vulnerable to chronic infection by a variant called clone 13.
Altman and his co-workers found that infecting mice with the Armstrong strain sequesters white blood cells in the lymph nodes, while clone 13 does so less stringently.
"Our hypothesis was that if we could artificially induce conditions like those produced by the Armstrong strain, it would help the immune system clear an infection by clone 13," says Altman.
His team turned to an experimental drug called FTY720, which prevents white blood cells from leaving lymph nodes.
FTY720, also known as fingolimod, desensitizes white blood cells so they can't respond to the chemical messenger sphingosine-1-phosphate (S1P). S1P also influences heart rate and smooth muscle contraction in the airways.
Scientists had previously thought of FTY720 as something that suppresses the immune system, Altman says. While not approved for sale by the FDA, doctors have tested it for the treatment of multiple sclerosis and preventing kidney transplant rejection.
Even if mice have a stable chronic LCMV clone 13 infection, treatment with FTY720 can still improve their immune response against LCMV enough to have them rid it from their systems, the authors found.
FTY720 appears to prevent "exhaustion" in the group of white blood cells called CD8+ T cells, which are responsible for killing off other cells that become infected by LCMV. Usually, the stress of infection kills some CD8+ T cells and leaves others unable to respond to the virus, Altman says.
It is unclear whether FTY720 resuscitates non-responsive T cells or allows new ones to avoid being killed off, he says.
Altman says he and his co-workers are planning to test FTY720's effects with other viruses.
Holly Korschun | EurekAlert!
Antibiotic effective against drug-resistant bacteria in pediatric skin infections
17.02.2017 | University of California - San Diego
Tiny magnetic implant offers new drug delivery method
14.02.2017 | University of British Columbia
In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport
Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...
The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.
The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...
Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...
Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".
Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...
13.02.2017 | Event News
10.02.2017 | Event News
09.02.2017 | Event News
17.02.2017 | Medical Engineering
17.02.2017 | Medical Engineering
17.02.2017 | Health and Medicine