Royal Ontario Museum scientist identifies Great Salt Lake as a significant source of greenhouse gas emissions

Desiccating salt lakes identified as underappreciated sources contributing to climate change

ROYAL ONTARIO MUSEUM

 

IMAGE: 

GREAT SALT LAKE, UTAH.

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CREDIT: PHOTO BY SOREN BROTHERS, © SOREN BROTHERS

Newly announced research by Royal Ontario Museum (ROM) examining greenhouse gas emissions from the drying lake bed of Great Salt Lake, Utah, calculates that 4.1 million tons of carbon dioxide and other greenhouse gases were released in 2020. This research suggests that drying lake beds are an overlooked but potentially significant source of greenhouse gases, which may further increase due to climate change. These results were announced in the paper, “A desiccating saline lake bed is a significant source of anthropogenic greenhouse gas emissions,” published in the journal One Earth.

“Human-caused desiccation of Great Salt Lake is exposing huge areas of lake bed and releasing massive quantities of greenhouse gases into the atmosphere,” said Soren Brothers, who led this research and is ROM’s Allan and Helaine Shiff Curator of Climate Change. “The significance of lake desiccation as a driver of climate change needs to be addressed in greater detail and considered in climate change mitigation and watershed planning.”

From year to year, Great Salt Lake’s water level varies, largely depending on the volume of meltwater that flows into the lake from the surrounding mountains — from record highs in the 1980s to a record low in 2022. However, it is human-related consumption by agriculture, industry, and municipal uses, that consume ever-increasing amounts of freshwater that, over the years, has depleted the lake. Elsewhere around the world, these same competing uses for water are having a significant impact on lake levels. As iconic saline lakes such as the Aral Sea, Lake Urmia, the Caspian Sea, and Great Salt Lake dry up, they not only destroy critical habitat for biodiversity and create air quality conditions that deteriorate human health, but they also accelerate climate change as newly exposed sediments emit carbon dioxide and methane.

The research team measured carbon dioxide and methane emissions from the exposed sediments of Great Salt Lake, Utah, from April to November 2020, and compared them with aquatic emissions estimates to determine the anthropogenic greenhouse gas emissions associated with desiccation. Calculations based on this sampling indicate the lake bed emitted 4.1 million tons of greenhouse gases to the atmosphere, primarily (94%) as carbon dioxide, constituting an approximately 7% increase to Utah’s human-caused greenhouse gas emissions.

Fieldwork was conducted while Soren Brothers was Assistant Professor of Limnology at Utah State University, and lead author, Melissa Cobo, was a master’s student at USU. Co-author Tobias Goldhammer is a collaborating researcher at the Leibniz Institute for Freshwater Research (IGB Institute) in Berlin, Germany. Measurements of carbon dioxide and methane gases were made every two weeks from the dried-up lake bed using a portable greenhouse gas analyzer attached to a closed chamber. Seven sites at one location at the south end of the lake were visited repeatedly over the course of the year, and another three locations were sampled during an intensive three-day campaign to determine spatial variability across the lake, which at 1,700 square miles (4,400 square kilometres) is the largest saline lake in the western hemisphere. As methane is 28 times more powerful a greenhouse gas than carbon dioxide, the global warming impact of these emissions was calculated as “carbon dioxide equivalents” to account for the greater impact of methane. Ultimately, these data indicated that greenhouse gas emissions from the dried lake bed were strongly and positively related to warm temperatures, even at sites that have been exposed for over two decades. To determine whether the lake historically would have been a significant source of greenhouse gases, the team carried out measurements of near-shore greenhouse gas emissions from the lake, as well as analyzing water chemistry collected by the team and government data sets. Together, these analyses showed that the original lake was not likely a significant source of greenhouse gases to the atmosphere, making the dried-up lake bed a novel driver of atmospheric warming.

As climate change exacerbates drought in arid regions, desiccation of rivers and lakes may be contributing to climate change feedback loops and should be considered in assessments of global greenhouse gas output as well as reduction policies and efforts.

Fieldwork gas sampling 

Sampling gas emissions from the lake bed of Great Salt Lake.

CREDIT

Photo by Soren Brothers, © Soren Brothers

Great Salt Lake, Utah.

CREDIT

Photo by Soren Brothers, © Soren Brothers

JOURNAL

One Earth

DOI

10.1016/j.oneear.2024.07.001 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

A desiccating saline lake bed is a significant source of anthropogenic greenhouse gas emissions

ARTICLE PUBLICATION DATE

25-Jul-2024

 

Wash U researchers quantify solar absorption by black carbon in fire clouds

New findings from Chakrabarty lab will help make climate models more accurate as massive wildfires become more common

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WASHINGTON UNIVERSITY IN ST. LOUIS

In an actively warming world, large-scale wildfires are becoming more common. These wildfires emit black carbon to our atmosphere, one of the most potent short-lived atmospheric warming agents. This is because of its strong sunlight absorption characteristics. But scientists have yet to get a handle on the extent of atmospheric warming caused by black carbon in pyrocumulonimbus (pyroCb) clouds that develop from high-intensity wildfires.

In their most extreme form, these wildfire clouds will inject smoke into the upper troposphere and lower stratosphere where it can linger and impact stratospheric temperatures and composition for several months. Some of the details of that impact have been investigated now thanks to new research from Washington University in St. Louis’ Center for Aerosol Science & Engineering (CASE).

The research was led by Rajan Chakrabarty, a professor in WashU’s McKelvey School of Engineering and his former student Payton Beeler, now a Linus Pauling distinguished post-doctoral fellow at Pacific Northwest National Laboratory. The study was published in Nature Communications.

“This work addresses a key challenge in quantifying black carbon’s radiative effect in the upper atmosphere,” Chakrabarty said.

The team made airborne measurements from within the upper portion of an active pyroCb thunderstorm in Washington state as part of the 2019 NOAA/NASA Fire Influence on Regional to Global Environments and Air Quality (FIREX-AQ) field campaign, he added.

“We considered the full complexity and diversity of the measured black carbon size and morphology on a per-particle basis for accurate estimation of its solar absorption. What we discovered is that a pyroCb black carbon particle absorbs visible sunlight two times as much as a nascent black carbon particle emitted from smaller fires and urban sources,” he said.

The authors uniquely combined measurements of black carbon mass and the thickness of organic coatings on individual particles in the plumes with a detailed single-particle optics model. They used a numerically exact particle-resolved model to calculate the black carbon optical properties and quantified how much light those black carbon particles are absorbing (and thus how much more heat they bring to the upper atmosphere).

In addition, the work highlights the unique light absorption properties of black carbon in pyroCbs clouds versus black carbon from wildfires that does not end up in pyroCbs and black carbon from urban sources.

The next step in this research is to take further measurements and do a more precise study of the black carbon behavior in the stratosphere.

Black carbon injected into the lower stratosphere by recent pyroCb events in Canada and Australia have traveled around the globe, persisted for months, and altered dynamic circulation and radiative forcing across large regions, Chakrabarty noted. These thunderstorms are deemed responsible for 10% to 25% of the black carbon in the present day lower stratosphere, with impacts extending to both the Northern and Southern Hemispheres. Scientists are increasingly observing how much it impacts climate but there is more to learn.

“We need more direct measurements of pyroCb black carbon light absorption measurements to better constrain climate model predictions of stratospheric warming,” Chakrabarty said.

 

Beeler P,  Kumar J,  Schwarz JP, Adachi K, Fierce L, Perring AE, Katich JM, Chakrabarty RK. Light absorption enhancement of black carbon in a pyrocumulonimbus cloud. Nat Commun 15, 6243 (2024). DOI: https://doi.org/10.1038/s41467-024-50070-0

 

This research has been supported by the National Aeronautics and Space Administration (grant nos. 80NSSC18K1414 and NNH20ZDA001N- ACCDAM), the National Oceanic and Atmospheric Administration (grant no. NA16OAR4310104), the National Science Foundation (grant nos. AGS-1455215 and AGS-1926817), the US Department of Energy (grant no. DE-SC0021011), and the Simons Foundation’s Mathematics and Physical Sciences division. L.F. was supported by the U.S. Department of Energy (DOE) Atmospheric System Research (ASR) program via the Integrated Cloud, Land-Surface, and Aerosol System Study (ICLASS) Science Focus Area. Additional support was provided by the Laboratory Directed Research and Development program (Linus Pauling Distinguished Postdoctoral Fellowship Program). Pacific Northwest National Laboratory is operated for DOE by Battelle Memorial Institute under contract DE-AC05-76RL01830.

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JOURNAL

Nature Communications

DOI

10.1038/s41467-024-50070-0 

 

New clam species discovered in South Africa’s kelp forest

PENSOFT PUBLISHERS

 

VIDEO: 

THE NEW CLAM SPECIES, BRACHIOMYA DUCENTIUNUS, FEEDING BETWEEN THE SPINES OF A SEA URCHIN.

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CREDIT: CRAIG FOSTER

A new study sheds light on the unexplored diversity of galeommatoidean bivalves, a little-known group of marine mollusks, from the western coast of South Africa. The research, led by Paul Valentich-Scott from the Santa Barbara Museum of Natural History, along with collaborators from the University of Cape Town, Sea Change Trust, Stellenbosch University, and the University of Colorado Boulder, offers a curious glimpse into the habitats, symbiotic relationships, and taxonomy of these interesting creatures.

Published in the scientific journal ZooKeys, the study focuses on four species of galeommatoidean bivalves collected from the Western Cape region of South Africa. Among these is one new species, Brachiomya ducentiunus. This small clam, which is only 2 mm (less than 1/8th inch) in length, spends its life crawling between the spines of sea urchins.

The new species has so far only been found in one locality in False Bay, South Africa, where it was found attached to the burrowing sea urchin Spatagobrissus mirabilis in coarse gravel at a depth of about 3 m. It has not been observed free-living, without the host urchin.

Brachiomya ducentiunus was discovered while preparing and working on the 1001 Seaforest Species project, a research and storytelling program aimed at increasing awareness of regional kelp bed ecosystems colloquially referred to as ‘the Great African Seaforest’.

"This study marks a significant advancement in our understanding of the biodiversity and ecological interactions of galeommatoidean bivalves," says lead author Paul Valentich-Scott. "By uncovering the hidden lives of these small but ecologically important organisms, we hope to contribute to the broader knowledge of marine biodiversity and the conservation of these unique habitats."

Co-author Charles L. Griffiths, emeritus professor at the University of Cape Town, says, “A large proportion of smaller marine invertebrates remain undescribed in western South Africa and almost any project that samples specialized habitats turns up many new records and species.”

In a similar vein, co-author Jannes Landschoff, marine biologist at the Sea Change Trust, says “Creating foundational biodiversity knowledge is a most important step to the humbling realization of how fascinating and uniquely diverse a place is. I see this every day through our work in the rich coastal waters of Cape Town, where an extensive underwater kelp forest, the ‘Great African Seaforest,’ grows.”

  

The newly discovered species, Brachiomya ducentiunus, crawing on a sea urchin spine.

CREDIT

Craig Foster

An unusual galeommatid clam, Melliteryx mactroides, living in tidepools near Cape Town, South Africa.

An unusual galeommatid clam, M [VIDEO] | 

CREDIT

Jannes Landschoff

Dozens of Brachiomya ducentiunus crawling on the surface of a sea urchin.

CREDIT

Charles Griffiths

Research article: 

Valentich-Scott P, Griffiths C, Landschoff J, Li R, Li J (2024) Bivalves of superfamily Galeommatoidea (Mollusca, Bivalvia) from western South Africa, with observations on commensal relationships and habitats. ZooKeys 1207: 301-323. https://doi.org/10.3897/zookeys.1207.124517

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JOURNAL

ZooKeys

DOI

10.3897/zookeys.1207.124517 

ARTICLE TITLE

Bivalves of superfamily Galeommatoidea (Mollusca, Bivalvia) from western South Africa, with observations on commensal relationships and habitats

ARTICLE PUBLICATION DATE

22-Jul-2024

 

The ancestor of all modern birds probably had iridescent feathers

A family tree of 9,409 bird species helped scientists figure out why there are so many colorful birds in the tropics and how these colors spread over time

FIELD MUSEUM

 

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BIRDS-OF-PARADISE IN THE FIELD MUSEUM'S COLLECTIONS

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CREDIT: KATE GOLEMBIEWSKI, FIELD MUSEUM

The color palette of the birds you see out your window depend on where you live. If you’re far from the Equator, most birds tend to have drab colors, but the closer you are to the tropics, you’ll probably see more and more colorful feathers. Scientists have long been puzzled about why there are more brilliantly-colored birds in the tropics than in other places, and they’ve also wondered how those brightly-colored birds got there in the first place: that is, if those colorful feathers evolved in the tropics, or if tropical birds have colorful ancestors that came to the region from somewhere else. In a new study published in the journal Nature Ecology and Evolution, scientists built a database of 9,409 birds to explore the spread of color across the globe. They found that iridescent, colorful feathers originated 415 times across the bird tree of life, and in most cases, arose outside of the tropics– and that the ancestor of all modern birds likely had iridescent feathers, too.

“For decades, scientists have had this hypothesis that there are brighter or more colorful species of birds in the tropics,” says Chad Eliason, a research scientist at the Field Museum in Chicago and the paper’s lead author. “We wanted to find the mechanism to help us understand these trends-- how these bright colors got there and how they spread across the bird family tree over time.”

There are two main ways that color is produced in animals: pigments and structures. Cells produce pigments like melanin, which is responsible for black and brown coloration. Meanwhile, structural color comes from the way light bounces off different arrangements of cell structures. Iridescence, the rainbow shimmer that changes depending how light hits an object, is an example of structural color.

Tropical birds get their colors from a combination of brilliant pigments and structural color. Eliason’s work focuses on structural color, so he wanted to explore that element of tropical bird coloration. He and his colleagues combed through photographs, videos, and even scientific illustrations of 9,409 species of birds-- the vast majority of the 10,000-ish living bird species known to science. The researchers kept track of which species have iridescent feathers, and where those birds are found.

The scientists then combined their data on bird coloration and distribution with a pre-existing family tree, based on DNA, showing how all the known bird species are related to each other. They fed the information to a modeling system to extrapolate the origins and spread of iridescence. “Basically, we did a lot of math,” says Eliason.

Given how modern species are related to each other and where they're found, and overall patterns of how species form and how traits like colors change over time, the modeling software determined the most likely explanation for the bird colors we see today: colorful birds from outside the tropics often came to the region millions of years ago, and then branched out into more and more different species. The model also revealed a surprise about the ancestor of all modern birds.

For background, birds are a specialized group of dinosaurs-- the earliest known bird, Archaeopteryx, lived 140 million years ago. A sub-group of birds called Neornithes evolved 80 million years ago, and this group became the only birds (and dinosaurs) to survive the mass extinction 66 million years ago. All modern birds are members of Neornithes. The model produced by Eliason and his colleagues suggests that the common ancestor of all Neornithes, 80 million years ago, had iridescent feathers that still glitter across the bird family tree.

“I was very excited to learn that the ancestral state of all birds is iridescence,” says Eliason. “We’ve found fossil evidence of iridescent birds and other feathered dinosaurs before, ​​by examining fossil feathers and the preserved pigment-producing structures in those feathers. So we know that iridescent feathers existed back in the Cretaceous-- those fossils help support the idea from our model that the ancestor of all modern birds was iridescent too.”

The discovery that the first Neornithes was likely iridescent could have important implications for paleontology. ”We’re probably going to be finding a lot more iridescence in the fossil record now that we know to look,” says Eliason.

While this new study sheds light on how iridescence spread through the bird family tree over the course of millions of years, some big questions remain. “We still don’t know why iridescence evolved in the first place,” says Eliason. “Iridescent feathers can be used by birds to attract mates, but iridescence is related to other aspects of birds’ lives too. For instance, tree swallows change color when the humidity changes, so iridescence could be related to the environment, or it might be related to another physical property of feathers, like water resistance. But knowing more about how there came to be so many iridescent birds in the tropics might help us understand why iridescence evolved.”

This study was contributed to by Chad M. Eliason of the Field Museum’s Grainger Bioinformatics Center and Negaunee Integrative Research Center, Michaël P.J. Nicolaï of Ghent University and the Royal Belgian Institute of Natural Sciences, Cynthia Bom of Vrije Universiteit Amsterdam, Eline Blom of Naturalis Biodiversity Center, Liliana D’Alba of Ghent University and Naturalis Biodiversity Center, and Matthew D. Shawkey of Ghent University.

 

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Lead author Chad Eliason with hummingbirds in the Field Museum's collections.

CREDIT

Kate Golembiewski, Field Museum

A blue-headed sunbird in the Albertine Rift: an example of a tropical bird with iridescent, colorful feathers. 

CREDIT

John Bates, Field MuseumJOURNAL

Nature Ecology & Evolution

ARTICLE TITLE

Why are there so many structurally coloured bird species in the tropics?

ARTICLE PUBLICATION DATE

26-Jul-2024

 

A soft needle in an oceanic haystack

Rare discovery of new soft-bodied vertebrate fossil in American Great Basin region will augment understanding of vertebrate evolution

HARVARD UNIVERSITY

 

IMAGE: 

NUUCICHTHYS RHYNCHOCEPHALUS IS THE FIRST SOFT-BODIED VERTEBRATE FROM THE AMERICAN GREAT BASIN. 

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CREDIT: FRANZ ANTHONY

The Cambrian fossil record indicates that most animal phyla had diversified and inhabited the Earth’s oceans approximately 518 million years ago. But even though chordates—the group that includes vertebrates like humans—were part of this early animal diversification, they make up a relatively small portion of fossils from more than 50 Cambrian sites worldwide.

In a new paper published in Royal Society Open Science, Harvard research scientist Rudy Lerosey-Aubril and associate professor Javier Ortega-Hernández present their surprising finding of a new species of chordate, and the first soft-bodied vertebrate to be discovered in the Drumian Marjum Formation of the American Great Basin.

This new fossil was part of a collection of Cambrian soft-bodied fossils deposited in the Museum of Natural History of Utah, a long term collaborator with researchers at Harvard.

The discovery of this new species, dubbed Nuucichthys rhynchocephalus, is a valuable contribution to early vertebrate evolution and biodiversity because of the dearth of these types of organisms in Cambrian fossil sites—including South China, the Northeastern United States, and British Columbia.

Nuucichthys is also one of only four species documenting the early evolutionary stage of vertebrate lineage and, as such, is one of humanity’s oldest relatives.

In their paper, Lerosey-Aubril and Ortega-Hernández describe Nuucichthys as having a finless torpedo-shaped body that includes a number of markers characteristic of vertebrates.

“Early vertebrates start to have big eyes and a series of muscle blocks that we call myotomes, and this is something we recognize very well in our fossil,” Lerosey-Aubril said.

The new species also confirms that, despite their overall similarities to larval fish—having a cavity that is a sort of rudimentary gill system—they were devoid of fins and therefore had limited swimming capabilities.

“But all of these characteristics clearly point to some vertebrate affinities,” Lerosey-Aubril said. “And because it's very early in the evolution of the vertebrates, they don't have bones yet—this is why these fossils are exceedingly rare.”

Lerosey-Aubril and Ortega-Hernández speculate that Nuucichthys likely lived high up in the water column of the ocean. Because of this, and because it possessed no biomineralized parts like bones or a shell, it was particularly prone to rapid post-mortem degradation and decay, which explains why they were fossilized so rarely.

“What’s interesting with this new species is that understanding how the morphology evolved from the invertebrate type to the vertebrate type is difficult without fossils, and this new fossil tells us a little bit about that,” Ortega-Hernández said.

The Drumian Marjum site where the new fossil was found has been intensively investigated since 2022 by an international group of paleontologists led by Lerosey-Aubril and Ortega-Hernández, and both believe that continuous collecting efforts at this site may result in the discovery of new specimens of Nuucichthys rhynchocephalus in the future.

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JOURNAL

Royal Society Open Science

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

A long-headed Cambrian soft-bodied vertebrate from the American Great Basin region

ARTICLE PUBLICATION DATE

24-Jul-2024

 

Ancient DNA analyses imply brucellosis evolved with development of farming

TRINITY COLLEGE DUBLIN

 

IMAGE: 

THE 8,000-YEAR-OLD SHEEP BONE FROM WHICH DNA WAS EXTRACTED.

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CREDIT: DR KEVIN DALY

Scientists believe the bacterial infection brucellosis, which affects millions of people every year and causes significant harm to the welfare of livestock, may have evolved along with the development of farming. They came to this conclusion after performing analyses of ancient DNA extracted from an 8,000-year-old sheep bone, in which the Brucella melitensis pathogen was detected.

Passed on by the consumption of unpasteurised milk and close contact with infected animals, brucellosis can cause waves of undulating fever and, tragically, the infection-related loss of pregnancy in pregnant women. Now, researchers have recovered a millennia-old genome of the sheep, goat, and human-infecting pathogen.

Recently published in the leading journal Nature Communications, the study reveals that the pathogen responsible for most brucellosis infections, Brucella melitensis, existed over 8,000 years ago in Neolithic times. 

Pathogen evolution and ancient DNA

How long have we lived with disease-causing pathogens? How and when did the pathogens which infect both humans and animals – known as zoonoses – evolve? And did we play a role in their evolution? These are questions which have long challenged researchers, particularly due to the difficulty of studying the deep past. 

But recent advances in the field of ancient DNA – the sequencing of genomes from organisms thousands of years in the past, from DNA typically preserved in bones and teeth – have allowed these questions to be directly addressed.

Ancient Brucella

In this study an international team of geneticists and archaeologists succeeded in detecting the Brucella in DNA from an 8,000-year-old sheep bone from Menteşe Höyük, an archaeological settlement in Northwest Türkiye, which shows the pathogen was circulating in herds of the world's first animal farmers.

“Looking for ancient pathogen DNA is like looking for a needle in a haystack,” says Louis L'Hôte, PhD student in Trinity College Dublin’s School of Genetics and Microbiology, and lead author of the study.

“It requires well preserved DNA and the presence of the infectious agent during the life of the animal. We were lucky enough to detect the presence of Brucella melitensis in Menteşe Höyük, which is a sign that the bacteria was infecting livestock during the Neolithic.” 

The evolution of different pathogens

Using the genome, the researchers were able to time when Brucella melitensis, which typically infects sheep and goats, evolved from its shared ancestor with Brucella abortus, which mostly infects cattle. They estimate that this happened ~9,800 years ago, in a period known as the Neolithic, when crop and livestock farming first developed. 

Intriguingly, this overlaps with when livestock keeping had become more developed, with farming communities keeping a mixture of animals. 

Farming and pathogen host-jumping

“By bringing together animals such as sheep, goat, cattle and pigs, which may rarely have lived in the same spaces together, early livestock farmers may have created an evolutionary melting pot for pathogen host-jumping, says Dr Kevin Daly, Ad Astra Assistant Professor at University College Dublin (and formerly of Trinity), who supervised the study. 

“For as long as we have kept animals as livestock, humanity has risked disease exposure – a problem we still grapple with 10,000 years later,” he adds.

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JOURNAL

Nature Communications

DOI

10.1038/s41467-024-50536-1 

 

CU Anschutz scientists identify key protein behind spread of shingles virus

For the first time, researchers identify the mechanism that allows the varicella zoster virus to spread far from the infection site

UNIVERSITY OF COLORADO ANSCHUTZ MEDICAL CAMPUS

 

VIDEO: 

THE VARICELLA ZOSTER VIRUS, WHICH RESIDES IN OVER 95% OF US, CAUSES CHICKEN POX AND THE MORE SERIOUS SHINGLES INFECTION.  CUANSCHUTZ RESEARCHERS HAVE DISCOVERED HOW THE VIRUS SPREADS SO RAPIDLY THROUGHOUT OUR BODIES, WHICH HAS OPENED A PATH TO FINDING A TREATMENT THAT COULD STOP SHINGLES AND ITS RELATED COMPLICATIONS.

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CREDIT: UNIVERSITY OF COLORADO ANSCHUTZ MEDICAL CAMPUS

AURORA, Colo. (July 25, 2024) –  Scientists at the University of Colorado Anschutz Medical Campus have discovered a new evasion strategy used by the varicella zoster virus, which causes chickenpox and shingles, that may allow it to affect tissues far from the original site of infection.

The study was published today in the Journal of Virology.

The researchers, using human neurons and rodent models, honed in on a single viral protein known as IE62 that is packaged and shuttled throughout the body in structures known as small extracellular vesicles (sEVs). They discovered that IE62 packaged inside sEVs can travel from the site of infection, where it penetrates cells and shuts down their antiviral response, opening the door to infection by the virus.

The virus, known as VZV, is ancient and common, residing within 95% of all people. Its primary infection causes chickenpox, which then goes latent. During stress, aging, or other factors, VZV can reactivate into shingles, a painful skin disease that can also attack the central nervous system and can lead to vascular disease, stroke, dementia, and other serious conditions.

To rapidly spread throughout the body, the virus needs an immediate strategy to evade the immune system. This study is the first to show exactly how it does this by exploiting the infected cells sEV machinery.

“This is the first time a clear mechanism has been found that actually ties this virus to an avenue by which it can affect distal organs, far from the site of infection,” said the study’s first author, Christy Niemeyer, PhD, assistant professor of neurology at the University of Colorado School of Medicine.  “These vesicles shut down the immune response.”

The study’s senior author Andrew Bubak, PhD, assistant professor of neurology at the CU School of Medicine, said the protein shuts down the anti-viral response in the cells far sooner than previously known.

“We believe this protein is likely being packaged into sEVs and shuttled down the neurons that go to your skin, making the cells under the skin vulnerable to the whole infection,” Bubak said. “We think this precedes the rash, which is obviously interesting from a therapeutic standpoint.”

While there is a vaccine for shingles, there are currently no drugs to impact the activity of this protein. That could change.

“This study is the first to identify a different anti-viral target that perhaps we can develop therapeutics for,” Niemeyer said.

Bubak said this mechanism may be responsible for the prevalent co-infections and immunosuppressive events seen clinically in those infected with VZV. He also noted that the virus can intermittently reactivate in individuals without the classic shingles rash, evading diagnosis and raising the question of whether this immunosuppressive event occurs more frequently than originally thought.

“This mechanism can offer us clues into how other viruses work and cause infection,” he said.

Niemeyer agreed, saying the significance of sEVs in the spread of this virus highlights the need for further investigation.

“We need to better understand their role in viral spread and secondary disease development to reduce the systemic complications caused by VZV infections,” she said.

About the University of Colorado Anschutz Medical Campus

The University of Colorado Anschutz Medical Campus is a world-class medical destination at the forefront of transformative science, medicine, education and patient care. The campus encompasses the University of Colorado health professional schools, more than 60 centers and institutes, and two nationally ranked independent hospitals - UCHealth University of Colorado Hospital and Children's Hospital Colorado - that treat more than two million adult and pediatric patients each year. Innovative, interconnected and highly collaborative, the University of Colorado Anschutz Medical Campus delivers life-changing treatments, patient care and professional training and conducts world-renowned research fueled by over $705 million in research grants. For more information, visit www.cuanschutz.edu.

 

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JOURNAL

Journal of Virology

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Animal tissue samples

ARTICLE TITLE

Suppression of the host antiviral response by non-infectious varicella zoster virus extracellular vesicles

ARTICLE PUBLICATION DATE

25-Jul-2024